@article{WinklerHeinken2007, author = {Winkler, Eckart and Heinken, Thilo}, title = {Spread of an ant-dispersed annual herb : an individual-based simulation study on population development of Melampyrum pratense L.}, issn = {0304-3800}, year = {2007}, abstract = {The paper presents a simulation and parameter-estimation approach for evaluating stochastic patterns of population growth and spread of an annual forest herb, Melampyrum pratense (Orobanchaceae). The survival of a species during large-scale changes in land use and climate will depend, to a considerable extent, on its dispersal and colonisation abilities. Predictions on species migration need a combination of field studies and modelling efforts. Our study on the ability of M. pratense to disperse into so far unoccupied areas is based on experiments in secondary woodland in NE Germany. Experiments started in 1997 at three sites where the species was not yet present, with 300 seeds sown within 1m2. Population development was then recorded until 2001 by mapping of individuals with a resolution of 5 cm. Additional observations considered density dependence of seed production. We designed a spatially explicit individual-based computer simulation model to explain the spatial patterns of population development and to predict future population spread. Besides primary drop of seeds (barochory) it assumed secondary seed transport by ants (myrmecochory) with an exponentially decreasing dispersal tail. An important feature of population-pattern explanation was the simultaneous estimation of both population-growth and dispersal parameters from consistent spatio-temporal data sets. As the simulation model produced stochastic time series and random spatially discrete distributions of individuals we estimated parameters by minimising the expectation of weighted sum of squares. These sums of squares criteria considered population sizes, radial population distributions around the area of origin and distributions of individuals within squares of 25cm×25 cm, the range of density action. Optimal parameter values, together with the precision of the estimates, were obtained from calculating sum of squares in regular grids of parameter values. Our modelling results showed that transport of fractions of seeds by ants over distances of 1-2m was indispensable for explaining the observed population spread that led to distances of at most 8mfrom population origin within 3 years. Projections of population development over four additional years gave a diffusion-like increase of population area without any "outposts". This prediction generated by the simulation model gave a hypothesis which should be revised by additional field observations. Some structural deviations between observations and model output already indicated that for full understanding of population spread the set of dispersal mechanisms assumed in the model may have to be extended by additional features of plant-animal mutualism.}, language = {en} } @article{VerheyenBaetenDeFrenneetal.2012, author = {Verheyen, Kris and Baeten, Lander and De Frenne, Pieter and Bernhardt-R{\"o}mermann, Markus and Brunet, Jorg and Cornelis, Johnny and Decocq, Guillaume and Dierschke, Hartmut and Eriksson, Ove and Hedl, Radim and Heinken, Thilo and Hermy, Martin and Hommel, Patrick and Kirby, Keith J. and Naaf, Tobias and Peterken, George and Petrik, Petr and Pfadenhauer, Joerg and Van Calster, Hans and Walther, Gian-Reto and Wulf, Monika and Verstraeten, Gorik}, title = {Driving factors behind the eutrophication signal in understorey plant communities of deciduous temperate forests}, series = {The journal of ecology}, volume = {100}, journal = {The journal of ecology}, number = {2}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0022-0477}, doi = {10.1111/j.1365-2745.2011.01928.x}, pages = {352 -- 365}, year = {2012}, abstract = {1. Atmospheric nitrogen (N) deposition is expected to change forest understorey plant community composition and diversity, but results of experimental addition studies and observational studies are not yet conclusive. A shortcoming of observational studies, which are generally based on resurveys or sampling along large deposition gradients, is the occurrence of temporal or spatial confounding factors. 2. We were able to assess the contribution of N deposition versus other ecological drivers on forest understorey plant communities by combining a temporal and spatial approach. Data from 1205 (semi-)permanent vegetation plots taken from 23 rigorously selected understorey resurvey studies along a large deposition gradient across deciduous temperate forest in Europe were compiled and related to various local and regional driving factors, including the rate of atmospheric N deposition, the change in large herbivore densities and the change in canopy cover and composition. 3. Although no directional change in species richness occurred, there was considerable floristic turnover in the understorey plant community and a shift in species composition towards more shade-tolerant and nutrient-demanding species. However, atmospheric N deposition was not important in explaining the observed eutrophication signal. This signal seemed mainly related to a shift towards a denser canopy cover and a changed canopy species composition with a higher share of species with more easily decomposed litter. 4. Synthesis. Our multi-site approach clearly demonstrates that one should be cautious when drawing conclusions about the impact of atmospheric N deposition based on the interpretation of plant community shifts in single sites or regions due to other, concurrent, ecological changes. Even though the effects of chronically increased N deposition on the forest plant communities are apparently obscured by the effects of canopy changes, the accumulated N might still have a significant impact. However, more research is needed to assess whether this N time bomb will indeed explode when canopies will open up again.}, language = {en} } @article{VannesteValdesVerheyenetal.2018, author = {Vanneste, Thomas and Valdes, Alicia and Verheyen, Kris and Perring, Michael P. and Bernhardt-Roemermann, Markus and Andrieu, Emilie and Brunet, Jorg and Cousins, Sara A. O. and Deconchat, Marc and De Smedt, Pallieter and Diekmann, Martin and Ehrmann, Steffen and Heinken, Thilo and Hermy, Martin and Kolb, Annette and Lenoir, Jonathan and Liira, Jaan and Naaf, Tobias and Paal, Taavi and Wulf, Monika and Decocq, Guillaume and De Frenne, Pieter}, title = {Functional trait variation of forest understorey plant communities across Europe}, series = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, volume = {34}, journal = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, publisher = {Elsevier GmbH}, address = {M{\"u}nchen}, issn = {1439-1791}, doi = {10.1016/j.baae.2018.09.004}, pages = {1 -- 14}, year = {2018}, abstract = {Global environmental changes are expected to alter the functional characteristics of understorey herb-layer communities, potentially affecting forest ecosystem functioning. However, little is known about what drives the variability of functional traits in forest understories. Here, we assessed the role of different environmental drivers in shaping the functional trait distribution of understorey herbs in fragmented forests across three spatial scales. We focused on 708 small, deciduous forest patches located in 16 agricultural landscape windows, spanning a 2500-km macroclimatic gradient across the temperate forest biome in Europe. We estimated the relative effect of patch-scale, landscape-scale and macroclimatic variables on the community mean and variation of plant height, specific leaf area and seed mass. Macroclimatic variables (monthly temperature and precipitation extremes) explained the largest proportion of variation in community trait means (on average 77\% of the explained variation). In contrast, patch-scale factors dominated in explaining community trait variation (on average 68\% of the explained variation). Notably, patch age, size and internal heterogeneity had a positive effect on the community-level variability. Landscape-scale variables explained only a minor part of the variation in both trait distribution properties. The variation explained by shared combinations of the variable groups was generally negligible. These findings highlight the importance of considering multiple spatial scales in predictions of environmental-change effects on the functionality of forest understories. We propose that forest management sustainability could benefit from conserving larger, historically continuous and internally heterogeneous forest patches to maximise ecosystem service diversity in rural landscapes. (C) 2018 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.}, language = {en} } @article{TischewDierschkeSchwabeetal.2018, author = {Tischew, Sabine and Dierschke, Hartmut and Schwabe, Angelika and Garve, Eckhard and Heinken, Thilo and Holzel, Norbert and Bergmeier, Erwin and Remy, Dominique and Haerdtle, Werner}, title = {Pflanzengesellschaft des Jahres 2019: Die Glatthaferwiese}, series = {Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft}, journal = {Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft}, number = {38}, publisher = {Floristisch-Soziologische Arbeitsgemeinschaft}, address = {G{\"o}ttingen}, issn = {0722-494X}, doi = {10.14471/2018.38.011}, pages = {287 -- 295}, year = {2018}, abstract = {Um Themen des Schutzes von Pflanzengemeinschaften wirksamer in der breiten {\"O}ffentlichkeit zu kommunizieren wird der Vorstand der „Floristisch-Soziologischen Arbeitsgemeinschaft (FlorSoz)" ab 2019 eine „Pflanzengesellschaft des Jahres" ausrufen. Damit sollen politische und administrative Entscheidungs- und Umsetzungsprozesse zur Erhaltung der Vielfalt von {\"O}kosystemen und Pflanzengesellschaften in Deutschlands gezielt unterst{\"u}tzt werden. F{\"u}r das Jahr 2019 wurde die Glatthaferwiese ausgew{\"a}hlt. Sie z{\"a}hlt aktuell zu den durch Artenverarmung und Fl{\"a}chenr{\"u}ckgang besonders bedrohten Pflanzengesellschaften Deutschlands. Es sind deshalb dringend Maßnahmen zum Schutz und zur Wiederherstellung notwendig. Dieser Artikel gibt einen kurzen {\"U}berblick zur naturschutzfachlichen Bedeutung von Glatthaferwiesen und deren {\"O}kosystemleistungen sowie zur floristisch-soziologischen Erforschung, zu Ursachen ihres R{\"u}ckgangs und zu geeigneten Gegenmaßnahmen.}, language = {de} } @article{SchoepkeHeinzePaetzigetal.2019, author = {Sch{\"o}pke, Benito and Heinze, Johannes and P{\"a}tzig, Marlene and Heinken, Thilo}, title = {Do dispersal traits of wetland plant species explain tolerance against isolation effects in naturally fragmented habitats?}, series = {Plant ecology : an international journal}, volume = {220}, journal = {Plant ecology : an international journal}, number = {9}, publisher = {Springer}, address = {Dordrecht}, issn = {1385-0237}, doi = {10.1007/s11258-019-00955-8}, pages = {801 -- 815}, year = {2019}, abstract = {The effects of habitat fragmentation and isolation on plant species richness have been verified for a wide range of anthropogenically fragmented habitats, but there is currently little information about their effects in naturally small and isolated habitats. We tested whether habitat area, heterogeneity, and isolation affect the richness of wetland vascular plant species in kettle holes, i.e., small glacially created wetlands, in an agricultural landscape of 1 km(2) in NE Germany. We compared fragmentation effects with those of forest fragments in the same landscape window. Since wetland and forest species might differ in their tolerance to isolation, and because isolation effects on plant species may be trait dependent, we asked which key life history traits might foster differences in isolation tolerance between wetland and forest plants. We recorded the flora and vegetation types in 83 isolated sites that contained 81 kettle holes and 25 forest fragments. Overall, the number of wetland species increased with increasing area and heterogeneity, i.e., the number of vegetation types, while area was not a surrogate for heterogeneity in these naturally fragmented systems. Isolation did not influence the number of wetland species but decreased the number of forest species. We also found that seeds of wetland species were on average lighter, more persistent and better adapted to epizoochory, e.g., by waterfowl, than seeds of forest species. Therefore, we suggest that wetland species are more tolerant to isolation than forest species due to their higher dispersal potential in space and time, which may counterbalance the negative effects of isolation.}, language = {en} } @article{SchwarzerHeinkenLuthardtetal.2013, author = {Schwarzer, Christian and Heinken, Thilo and Luthardt, Vera and Joshi, Jasmin Radha}, title = {Latitudinal shifts in species interactions interfere with resistance of southern but not of northern bog-plant communities to experimental climate change}, series = {The journal of ecology}, volume = {101}, journal = {The journal of ecology}, number = {6}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0022-0477}, doi = {10.1111/1365-2745.12158}, pages = {1484 -- 1497}, year = {2013}, abstract = {The persistence of species under changed climatic conditions depends on adaptations and plastic responses to these conditions and on interactions with their local plant community resulting in direct and indirect effects of changed climatic conditions. Populations at species' range margins may be especially crucial in containing a gene pool comprising adaptations to extreme climatic conditions. Many species of northern European bog ecosystems reach their southern lowland range limit in central Europe. In a common-garden experiment, we experimentally assessed the impact of projected climatic changes on five bog-plant species (including peat moss Sphagnum magellanicum) sampled along a latitudinal gradient of 1400km from Scandinavia to the marginal lowland populations in Germany. Populations were cultivated in monocultures and in experimental communities composed of all five species from their local community, and exposed to five combinations of three climate treatments (warming, fluctuating water-tables, fertilization) in a southern common garden. Whereas most monocultures showed a decreasing biomass production from southern to northern origins under southern environmental conditions, in the experimental mixed-species communities, an increasing biomass production towards northern communities was observed together with a shift in interspecific interactions along the latitudinal gradient. While negative dominance effects prevailed in southern communities, higher net biodiversity effects were observed in northern subarctic communities. The combined effects of climate treatments increased biomass production in monocultures of most origins. In communities, however, overall the treatments did not result in significantly changed biomass production. Among individual treatments, water-table fluctuations caused a significant decrease in biomass production, but only in southern communities, indicating higher vulnerability to changed climatic conditions. Here, negative effects of climate treatments on graminoids were not compensated by the slightly increased growth of peat moss that benefited from interspecific interactions only in northern communities.Synthesis. We conclude that shifting interactions within multispecies communities caused pronounced responses to changed climatic conditions in wetland communities of temperate southern marginal, but not of northern subarctic origin. Therefore, future models investigating the impacts of climate change on plant communities should consider geographical variation in species interactions an important factor influencing community responses to changed climatic conditions.}, language = {en} } @article{SchwabeTischewBergmeieretal.2019, author = {Schwabe, Angelika and Tischew, Sabine and Bergmeier, Erwin and Garve, Eckhard and H{\"a}rdtle, Werner and Heinken, Thilo and H{\"o}lzel, Norbert and Peppler-Lisbach, Cord and Remy, Dominique and Dierschke, Hartmut}, title = {Pflanzengesellschaft des Jahres 2020}, series = {Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft}, journal = {Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft}, number = {39}, publisher = {Floristisch-soziologischen Arbeitsgemeinschaft e.V.}, address = {G{\"o}ttingen}, issn = {0722-494X}, doi = {10.14471/2019.39.017}, pages = {287 -- 308}, year = {2019}, abstract = {Wie erstmals 2019 wird auch f{\"u}r das Jahr 2020 von der „Floristisch-soziologischen Arbeitsgemeinschaft" (FlorSoz) f{\"u}r Deutschland die „Pflanzengesellschaft des Jahres" vorgestellt. Damit soll wiederum f{\"u}r die {\"O}ffentlichkeit die Notwendigkeit des Schutzes gef{\"a}hrdeter Pflanzengesellschaften aufgezeigt werden. F{\"u}r das Jahr 2020 wurden die Borstgrasrasen ausgew{\"a}hlt. Wie alle Pflanzengemeinschaften n{\"a}hrstoffarmer Standorte, sind auch die Borstgrasrasen stark gef{\"a}hrdet und regional sogar unmittelbar vom Aussterben bedroht. Wir konzentrieren uns vor allem auf die Best{\"a}nde der planaren bis montanen Stufe (Unterverband Violenion caninae: Hundsveilchen-Borstgrasrasen). Die Standorte von Violenion caninae-Gesellschaften werden nicht ged{\"u}ngt und sind auf extensive Beweidung, z.T. auch auf einsch{\"u}rige Mahd angewiesen. F{\"u}r Borstgrasrasen bezeichnend sind eine F{\"u}lle gef{\"a}hrdeter Pflanzenarten wie z.B. Arnica montana (Arnika) und Antennaria dioica (Zweih{\"a}usiges Katzenpf{\"o}tchen). Bei den Borstgrasrasen spielen f{\"u}r die zunehmend hohe Gef{\"a}hrdung nicht nur Fl{\"a}chenr{\"u}ckg{\"a}nge durch Nutzungsaufgabe, Aufforstung, Sport- und Freizeitaktivit{\"a}ten und {\"U}berbauung eine Rolle, sondern auch {\"A}nderungen der Struktur und Artenzusammensetzung durch direkte D{\"u}ngung sowie atmogene Stickstoffeintr{\"a}ge sind von Bedeutung. N{\"a}hrstoffanreicherungen f{\"u}hren zum Verlust der konkurrenzschwachen, gef{\"a}hrdeten Arten zugunsten einiger allgemein verbreiteter, h{\"a}ufig dominanter Gr{\"a}ser sowie konkurrenzkr{\"a}ftiger Kr{\"a}uter. Wir skizzieren die Bedeutung der Borstgrasrasen als gef{\"a}hrdete Lebensgemeinschaften, geben Hinweise zur floristisch-soziologischen Erforschung und zu weiteren Naturschutz-Aspekten (R{\"u}ckgang, Erhaltung, M{\"o}glichkeiten der Restitution). Ein wirksamer Schutz ist nur bei einem integrativen Naturschutzansatz mit geeigneter Nutzung m{\"o}glich.}, language = {de} } @article{SchulzeBuchwaldHeinken2014, author = {Schulze, Kiowa Alraune and Buchwald, Rainer and Heinken, Thilo}, title = {Epizoochory via the hooves - the European bison (Bison bonasus L.) as a dispersal agent of seeds in an open-forest-mosaic}, series = {Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft}, journal = {Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft}, number = {34}, publisher = {Floristisch-Soziologische Arbeitsgemeinschaft}, address = {G{\"o}ttingen}, issn = {0722-494X}, pages = {131 -- 144}, year = {2014}, abstract = {Large herbivores are significant vectors for the long-distance dispersal of seeds in various habitats, both attached to animals (epizoochory) and via gut passage (endozoochory). The majority of studies on epizoochory have examined dispersal in the fur of domesticated ungulates. Studies on wild ungulates are important to understand dispersal processes in many habitats, but rare due to methodological constraints. We studied epizoochory of seeds by European bison in an open-forest-mosaic (nutrient-poor grassland and heathland, mixed forest) in NW Germany, where bison had been introduced for the purpose of nature conservation. At the study site it was possible to apply a method by which hoof material of free-ranging bison was non-invasively collected. We identified a total of 1082 seeds from 32 plant species in the hoof material. The three most abundant species were Polygonum aviculare, Agrostis capillaris and Betula spp. Seed species originated from various habitat types of the study area, while the majority of seeds derived from trampled areas. Compared to the non-dispersed plant species of the study area, dispersed plant species had a higher seed longevity index, suggesting that many seeds were picked up from the soil seed bank. Epizoochory ranking indices of dispersed seed species, classifying the importance of epizoochory, revealed that transport in the fur may be of minor importance for many species, i.e. epizoochory by the hooves turned out to be negatively correlated to epizoochory in the fur. We conclude that European bison disperses a considerable number of seed species through trampling. Further research should consider epizoochory via the hooves and include integrative approaches to understand the different dispersal mechanisms by ungulates and their long-term synergetic effect on plant communities.}, language = {en} } @article{SchmidtFischerGuenzletal.2008, author = {Schmidt, Marcus and Fischer, Petra and G{\"u}nzl, Bettina and Heinken, Thilo and Kelm, Hans-J{\"u}rgen and Meyer, Peter and Pr{\"u}ter, Johannes and Waesch, Gunnar}, title = {Flechten-Kiefernw{\"a}lder : Artenvielfalt durch alte Nutzungsformen?}, issn = {1430-2713}, year = {2008}, language = {de} } @article{ReineckeKlemmHeinken2014, author = {Reinecke, Jennifer and Klemm, Gunther and Heinken, Thilo}, title = {Vegetation change and homogenization of species composition in temperate nutrient deficient scots pine forests after 45 yr}, series = {Journal of vegetation science}, volume = {25}, journal = {Journal of vegetation science}, number = {1}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {1100-9233}, doi = {10.1111/jvs.12069}, pages = {113 -- 121}, year = {2014}, abstract = {QuestionDoes eutrophication drive vegetation change in pine forests on nutrient deficient sites and thus lead to the homogenization of understorey species composition? LocationForest area (1600ha) in the Lower Spreewald, Brandenburg, Germany. MethodsResurvey of 77 semi-permanent plots after 45yr, including vascular plants, bryophytes and ground lichens. We applied multidimensional ordination of species composition, dissimilarity indices, mean Ellenberg indicator values and the concept of winner/loser species to identify vegetation change between years. Differential responses along a gradient of nutrient availability were analysed on the basis of initial vegetation type, reflecting topsoil N availability of plots. ResultsSpecies composition changed strongly and overall shifted towards higher N and slightly lower light availability. Differences in vegetation change were related to initial vegetation type, with strongest compositional changes in the oligotrophic forest type, but strongest increase of nitrophilous species in the mesotrophic forest type. Despite an overall increase in species number, species composition was homogenized between study years due to the loss of species (mainly ground lichens) on the most oligotrophic sites. ConclusionsThe response to N enrichment is confounded by canopy closure on the N-richest sites and probably by water limitation on N-poorest sites. The relative importance of atmospheric N deposition in the eutrophication effect is difficult to disentangle from natural humus accumulation after historical litter raking. However, the profound differences in species composition between study years across all forest types suggest that atmospheric N deposition contributes to the eutrophication, which drives understorey vegetation change and biotic homogenization in Central European Scots pine forests on nutrient deficient sites.}, language = {en} } @article{ReineckeWulfBaetenetal.2016, author = {Reinecke, J. and Wulf, M. and Baeten, Lander and Brunet, J. and Decocq, G. and De Frenne, G. and Diekmann, M. and Graae, B. J. and Heinken, Thilo and Hermy, M. and Jamoneau, A. and Lenoir, J. and Plue, J. and Orczewska, A. and Van Calster, H. and Verheyen, Kris and Naaf, T.}, title = {Acido- and neutrophilic temperate forest plants display distinct shifts in ecological pH niche across north-western Europe}, series = {Ecography : pattern and diversity in ecology ; research papers forum}, volume = {39}, journal = {Ecography : pattern and diversity in ecology ; research papers forum}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0906-7590}, doi = {10.1111/ecog.02051}, pages = {1164 -- 1175}, year = {2016}, abstract = {Ecological niches of organisms vary across geographical space, but niche shift patterns between regions and the underlying mechanisms remain largely unexplored. We studied shifts in the pH niche of 42 temperate forest plant species across a latitudinal gradient from northern France to boreo-nemoral Sweden. We asked 1) whether species restrict their niches with increasing latitude as they reach their northern range margin (environmental constraints); 2) whether species expand their niches with increasing latitude as regional plant species richness decreases (competitive release); and 3) whether species shift their niche position toward more acidic sites with increasing latitude as the relative proportion of acidic soils increases (local adaptation). Based on 1458 vegetation plots and corresponding soil pH values, we modelled species response curves using Huisman-Olff-Fresco models. Four niche measures (width, position, left and right border) were compared among regions by randomization tests. We found that with increasing latitude, neutrophilic species tended to retreat from acidic sites, indicating that these species retreat to more favorable sites when approaching their range margin. Alternatively, these species might benefit from enhanced nitrogen deposition on formerly nutrient-poor, acidic sites in southern regions or lag behind in post-glacial recolonization of potential habitats in northern regions. Most acidophilic species extended their niche toward more base-rich sites with increasing latitude, indicating competitive release from neutrophilic species. Alternatively, acidophilic species might benefit from optimal climatic conditions in the north where some have their core distribution area. Shifts in the niche position suggested that local adaptation is of minor importance. We conclude that shifts in the pH niche of temperate forest plants are the rule, but the directions of the niche shifts and possible explanations vary. Our study demonstrates that differentiating between acidophilic and neutrophilic species is crucial to identify general patterns and underlying mechanisms.}, language = {en} } @article{PlueDeFrenneAcharyaetal.2013, author = {Plue, Jan and De Frenne, Pieter and Acharya, Kamal P. and Brunet, Jorg and Chabrerie, Olivier and Decocq, Guillaume and Diekmann, Martin and Graae, Bente J. and Heinken, Thilo and Hermy, Martin and Kolb, Annette and Lemke, Isgard and Liira, Jaan and Naaf, Tobias and Shevtsova, Anna and Verheyen, Kris and Wulf, Monika and Cousins, Sara A. O.}, title = {Climatic control of forest herb seed banks along a latitudinal gradient}, series = {Global ecology and biogeography : a journal of macroecology}, volume = {22}, journal = {Global ecology and biogeography : a journal of macroecology}, number = {10}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {1466-822X}, doi = {10.1111/geb.12068}, pages = {1106 -- 1117}, year = {2013}, abstract = {Aim Seed banks are central to the regeneration strategy of many plant species. Any factor altering seed bank density thus affects plant regeneration and population dynamics. Although seed banks are dynamic entities controlled by multiple environmental drivers, climatic factors are the most comprehensive, but still poorly understood. This study investigates how climatic variation structures seed production and resulting seed bank patterns. Location Temperate forests along a 1900km latitudinal gradient in north-western (NW) Europe. Methods Seed production and seed bank density were quantified in 153 plots along the gradient for four forest herbs with different seed longevity: Geum urbanum, Milium effusum, Poa nemoralis and Stachys sylvatica. We tested the importance of climatic and local environmental factors in shaping seed production and seed bank density. Results Seed production was determined by population size, and not by climatic factors. G.urbanum and M.effusum seed bank density declined with decreasing temperature (growing degree days) and/or increasing temperature range (maximum-minimum temperature). P.nemoralis and S.sylvatica seed bank density were limited by population size and not by climatic variables. Seed bank density was also influenced by other, local environmental factors such as soil pH or light availability. Different seed bank patterns emerged due to differential seed longevities. Species with long-lived seeds maintained constant seed bank densities by counteracting the reduced chance of regular years with high seed production at colder northern latitudes. Main conclusions Seed bank patterns show clear interspecific variation in response to climate across the distribution range. Not all seed banking species may be as well equipped to buffer climate change via their seed bank, notably in short-term persistent species. Since the buffering capacity of seed banks is key to species persistence, these results provide crucial information to advance climatic change predictions on range shifts, community and biodiversity responses.}, language = {en} } @article{PlueDeFrenneAcharyaetal.2017, author = {Plue, Jan and De Frenne, Pieter and Acharya, Kamal and Brunet, J{\"o}rg and Chabrerie, Olivier and Decocq, Guillaume and Diekmann, Martin and Graae, Bente J. and Heinken, Thilo and Hermy, Martin and Kolb, Annette and Lemke, Isgard and Liira, Jaan and Naaf, Tobias and Verheyen, Kris and Wulf, Monika and Cousins, Sara A. O.}, title = {Where does the community start, and where does it end?}, series = {Journal of vegetation science}, volume = {28}, journal = {Journal of vegetation science}, number = {2}, publisher = {Wiley}, address = {Hoboken}, issn = {1100-9233}, doi = {10.1111/jvs.12493}, pages = {424 -- 435}, year = {2017}, abstract = {QuestionBelow-ground processes are key determinants of above-ground plant population and community dynamics. Still, our understanding of how environmental drivers shape plant communities is mostly based on above-ground diversity patterns, bypassing below-ground plant diversity stored in seed banks. As seed banks may shape above-ground plant communities, we question whether concurrently analysing the above- and below-ground species assemblages may potentially enhance our understanding of community responses to environmental variation. LocationTemperate deciduous forests along a 2000km latitudinal gradient in NW Europe. MethodsHerb layer, seed bank and local environmental data including soil pH, canopy cover, forest cover continuity and time since last canopy disturbance were collected in 129 temperate deciduous forest plots. We quantified herb layer and seed bank diversity per plot and evaluated how environmental variation structured community diversity in the herb layer, seed bank and the combined herb layer-seed bank community. ResultsSeed banks consistently held more plant species than the herb layer. How local plot diversity was partitioned across the herb layer and seed bank was mediated by environmental variation in drivers serving as proxies of light availability. The herb layer and seed bank contained an ever smaller and ever larger share of local diversity, respectively, as both canopy cover and time since last canopy disturbance decreased. Species richness and -diversity of the combined herb layer-seed bank community responded distinctly differently compared to the separate assemblages in response to environmental variation in, e.g. forest cover continuity and canopy cover. ConclusionsThe seed bank is a below-ground diversity reservoir of the herbaceous forest community, which interacts with the herb layer, although constrained by environmental variation in e.g. light availability. The herb layer and seed bank co-exist as a single community by means of the so-called storage effect, resulting in distinct responses to environmental variation not necessarily recorded in the individual herb layer or seed bank assemblages. Thus, concurrently analysing above- and below-ground diversity will improve our ecological understanding of how understorey plant communities respond to environmental variation.}, language = {en} } @article{PerringBernhardtRoemermannBaetenetal.2018, author = {Perring, Michael P. and Bernhardt-Roemermann, Markus and Baeten, Lander and Midolo, Gabriele and Blondeel, Haben and Depauw, Leen and Landuyt, Dries and Maes, Sybryn L. and De Lombaerde, Emiel and Caron, Maria Mercedes and Vellend, Mark and Brunet, Joerg and Chudomelova, Marketa and Decocq, Guillaume and Diekmann, Martin and Dirnboeck, Thomas and Doerfler, Inken and Durak, Tomasz and De Frenne, Pieter and Gilliam, Frank S. and Hedl, Radim and Heinken, Thilo and Hommel, Patrick and Jaroszewicz, Bogdan and Kirby, Keith J. and Kopecky, Martin and Lenoir, Jonathan and Li, Daijiang and Malis, Frantisek and Mitchell, Fraser J. G. and Naaf, Tobias and Newman, Miles and Petrik, Petr and Reczynska, Kamila and Schmidt, Wolfgang and Standovar, Tibor and Swierkosz, Krzysztof and Van Calster, Hans and Vild, Ondrej and Wagner, Eva Rosa and Wulf, Monika and Verheyen, Kris}, title = {Global environmental change effects on plant community composition trajectories depend upon management legacies}, series = {Global change biology}, volume = {24}, journal = {Global change biology}, number = {4}, publisher = {Wiley}, address = {Hoboken}, issn = {1354-1013}, doi = {10.1111/gcb.14030}, pages = {1722 -- 1740}, year = {2018}, abstract = {The contemporary state of functional traits and species richness in plant communities depends on legacy effects of past disturbances. Whether temporal responses of community properties to current environmental changes are altered by such legacies is, however, unknown. We expect global environmental changes to interact with land-use legacies given different community trajectories initiated by prior management, and subsequent responses to altered resources and conditions. We tested this expectation for species richness and functional traits using 1814 survey-resurvey plot pairs of understorey communities from 40 European temperate forest datasets, syntheses of management transitions since the year 1800, and a trait database. We also examined how plant community indicators of resources and conditions changed in response to management legacies and environmental change. Community trajectories were clearly influenced by interactions between management legacies from over 200 years ago and environmental change. Importantly, higher rates of nitrogen deposition led to increased species richness and plant height in forests managed less intensively in 1800 (i.e., high forests), and to decreases in forests with a more intensive historical management in 1800 (i.e., coppiced forests). There was evidence that these declines in community variables in formerly coppiced forests were ameliorated by increased rates of temperature change between surveys. Responses were generally apparent regardless of sites' contemporary management classifications, although sometimes the management transition itself, rather than historic or contemporary management types, better explained understorey responses. Main effects of environmental change were rare, although higher rates of precipitation change increased plant height, accompanied by increases in fertility indicator values. Analysis of indicator values suggested the importance of directly characterising resources and conditions to better understand legacy and environmental change effects. Accounting for legacies of past disturbance can reconcile contradictory literature results and appears crucial to anticipating future responses to global environmental change.}, language = {en} } @article{PauliukMuellerHeinken2011, author = {Pauliuk, Franziska and M{\"u}ller, J{\"o}rg and Heinken, Thilo}, title = {Bryophyte dispersal by sheep on dry grassland}, series = {Nova Hedwigia : Zeitschrift f{\"u}r Kryptogamenkunde}, volume = {92}, journal = {Nova Hedwigia : Zeitschrift f{\"u}r Kryptogamenkunde}, number = {3-4}, publisher = {Cramer}, address = {Stuttgart}, issn = {0029-5035}, doi = {10.1127/0029-5035/2011/0092-0327}, pages = {327 -- 341}, year = {2011}, abstract = {Many bryophytes may depend on epizoochorous dispersal by large mammals for maintaining their populations and colonizing new habitats. On dry grassland we investigated the transport of bryophyte diaspores by sheep, which are known to be effective epizoochorous dispersal vectors of seed plants. Twelve sheep of two breeds were examined by collecting gametophyte fragments from their fleece and hooves. Furthermore, microscopic diaspores from the soil adhering to the hooves were grown in a greenhouse. Species frequency and composition were compared to bryophyte vegetation on the pasture. Considerable amounts of unspecialized gametophyte fragments from 16 moss species, 40\% of the species growing on the pasture, were transported by sheep, especially on the belly and the tail. Additionally, we provide first evidence of epizoochorous dispersal of thallus fragments from fruticose lichens. Sheep breeds differed in species spectrum and frequency, i.e. sheep with dense, curly fleece carried more fragments and larger species than those with smooth and fine hair. Among the dispersed bryophytes pleurocarps, certain taxa, sizes (small species) and life forms (mats) were overrepresented compared to the vegetation of the pasture, while large species, acrocarps, wefts and turfs were underrepresented, reflecting fragmentation and adhesion features of the species. In the hooves mostly acrocarpous colonist species were transported. We conclude that sheep are important dispersal vectors with the potential of long-range dispersal for bryophytes, especially for species without sexual reproduction, and that epizoochorous dispersal of microscopic diaspores might be underestimated in its importance so far.}, language = {en} } @article{MaesPerringVanhellemontetal.2018, author = {Maes, Sybryn L. and Perring, Michael P. and Vanhellemont, Margot and Depauw, Leen and Van den Bulcke, Jan and Brumelis, Guntis and Brunet, Jorg and Decocq, Guillaume and den Ouden, Jan and H{\"a}rdtle, Werner and Hedl, Radim and Heinken, Thilo and Heinrichs, Steffi and Jaroszewicz, Bogdan and Kopeck{\´y}, Martin and Malis, Frantisek and Wulf, Monika and Verheyen, Kris}, title = {Environmental drivers interactively affect individual tree growth across temperate European forests}, series = {Global change biology}, volume = {25}, journal = {Global change biology}, number = {1}, publisher = {Wiley}, address = {Hoboken}, issn = {1354-1013}, doi = {10.1111/gcb.14493}, pages = {201 -- 217}, year = {2018}, abstract = {Forecasting the growth of tree species to future environmental changes requires abetter understanding of its determinants. Tree growth is known to respond to global-change drivers such as climate change or atmospheric deposition, as well as to localland-use drivers such as forest management. Yet, large geographical scale studiesexamining interactive growth responses to multiple global-change drivers are relativelyscarce and rarely consider management effects. Here, we assessed the interactiveeffects of three global-change drivers (temperature, precipitation and nitrogen deposi-tion) on individual tree growth of three study species (Quercus robur/petraea, Fagus syl-vatica and Fraxinus excelsior). We sampled trees along spatial environmental gradientsacross Europe and accounted for the effects of management for Quercus. We collectedincrement cores from 267 trees distributed over 151 plots in 19 forest regions andcharacterized their neighbouring environment to take into account potentially confounding factors such as tree size, competition, soil conditions and elevation. Wedemonstrate that growth responds interactively to global-change drivers, with species -specific sensitivities to the combined factors. Simultaneously high levels of precipita-tion and deposition benefited Fraxinus, but negatively affected Quercus' growth, high-lighting species-specific interactive tree growth responses to combined drivers. ForFagus, a stronger growth response to higher temperatures was found when precipita-tion was also higher, illustrating the potential negative effects of drought stress underwarming for this species. Furthermore, we show that past forest management canmodulate the effects of changing temperatures on Quercus' growth; individuals in plotswith a coppicing history showed stronger growth responses to higher temperatures.Overall, our findings highlight how tree growth can be interactively determined by glo-bal-change drivers, and how these growth responses might be modulated by past for-est management. By showing future growth changes for scenarios of environmentalchange, we stress the importance of considering multiple drivers, including past man-agement and their interactions, when predicting tree growth.}, language = {en} } @article{MaesBlondeelPerringetal.2019, author = {Maes, Sybryn L. and Blondeel, Haben and Perring, Michael P. and Depauw, Leen and Brumelis, Guntis and Brunet, J{\"o}rg and Decocq, Guillaume and den Ouden, Jan and Haerdtle, Werner and Hedl, Radim and Heinken, Thilo and Heinrichs, Steffi and Jaroszewicz, Bogdan and Kirby, Keith J. and Kopecky, Martin and Malis, Frantisek and Wulf, Monika and Verheyen, Kris}, title = {Litter quality, land-use history, and nitrogen deposition effects on topsoil conditions across European temperate deciduous forests}, series = {Forest ecology and management}, volume = {433}, journal = {Forest ecology and management}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0378-1127}, doi = {10.1016/j.foreco.2018.10.056}, pages = {405 -- 418}, year = {2019}, abstract = {Topsoil conditions in temperate forests are influenced by several soil-forming factors, such as canopy composition (e.g. through litter quality), land-use history, atmospheric deposition, and the parent material. Many studies have evaluated the effects of single factors on physicochemical topsoil conditions, but few have assessed the simultaneous effects of multiple drivers. Here, we evaluate the combined effects of litter quality, land-use history (past land cover as well as past forest management), and atmospheric deposition on several physicochemical topsoil conditions of European temperate deciduous forest soils: bulk density, proportion of exchangeable base cations, carbon/nitrogen-ratio (C/N), litter mass, bio-available and total phosphorus, pH(KCI)and soil organic matter. We collected mineral soil and litter layer samples, and measured site characteristics for 190 20 x 20 m European mixed forest plots across gradients of litter quality (derived from the canopy species composition) and atmospheric deposition, and for different categories of past land cover and past forest management. We accounted for the effects of parent material on topsoil conditions by clustering our plots into three soil type groups based on texture and carbonate concentration. We found that litter quality was a stronger driver of topsoil conditions compared to land-use history or atmospheric deposition, while the soil type also affected several topsoil conditions here. Plots with higher litter quality had soils with a higher proportion of exchangeable base cations, and total phosphorus, and lower C/N-ratios and litter mass. Furthermore, the observed litter quality effects on the topsoil were independent from the regional nitrogen deposition or the soil type, although the soil type likely (co)-determined canopy composition and thus litter quality to some extent in the investigated plots. Litter quality effects on topsoil phosphorus concentrations did interact with past land cover, highlighting the need to consider land-use history when evaluating canopy effects on soil conditions. We conclude that forest managers can use the canopy composition as an important tool for influencing topsoil conditions, although soil type remains an important factor to consider.}, language = {en} } @article{LozadaGobilardStangPirhoferWalzletal.2019, author = {Lozada Gobilard, Sissi Donna and Stang, Susanne and Pirhofer-Walzl, Karin and Kalettka, Thomas and Heinken, Thilo and Schr{\"o}der, Boris and Eccard, Jana and Joshi, Jasmin Radha}, title = {Environmental filtering predicts plant-community trait distribution and diversity}, series = {Ecology and evolution}, volume = {9}, journal = {Ecology and evolution}, number = {4}, publisher = {Wiley}, address = {Hoboken}, issn = {2045-7758}, doi = {10.1002/ece3.4883}, pages = {1898 -- 1910}, year = {2019}, abstract = {Meta-communities of habitat islands may be essential to maintain biodiversity in anthropogenic landscapes allowing rescue effects in local habitat patches. To understand the species-assembly mechanisms and dynamics of such ecosystems, it is important to test how local plant-community diversity and composition is affected by spatial isolation and hence by dispersal limitation and local environmental conditions acting as filters for local species sorting.We used a system of 46 small wetlands (kettle holes)natural small-scale freshwater habitats rarely considered in nature conservation policiesembedded in an intensively managed agricultural matrix in northern Germany. We compared two types of kettle holes with distinct topographies (flat-sloped, ephemeral, frequently plowed kettle holes vs. steep-sloped, more permanent ones) and determined 254 vascular plant species within these ecosystems, as well as plant functional traits and nearest neighbor distances to other kettle holes.Differences in alpha and beta diversity between steep permanent compared with ephemeral flat kettle holes were mainly explained by species sorting and niche processes and mass effect processes in ephemeral flat kettle holes. The plant-community composition as well as the community trait distribution in terms of life span, breeding system, dispersal ability, and longevity of seed banks significantly differed between the two habitat types. Flat ephemeral kettle holes held a higher percentage of non-perennial plants with a more persistent seed bank, less obligate outbreeders and more species with seed dispersal abilities via animal vectors compared with steep-sloped, more permanent kettle holes that had a higher percentage of wind-dispersed species. In the flat kettle holes, plant-species richness was negatively correlated with the degree of isolation, whereas no such pattern was found for the permanent kettle holes.Synthesis: Environment acts as filter shaping plant diversity (alpha and beta) and plant-community trait distribution between steep permanent compared with ephemeral flat kettle holes supporting species sorting and niche mechanisms as expected, but we identified a mass effect in ephemeral kettle holes only. Flat ephemeral kettle holes can be regarded as meta-ecosystems that strongly depend on seed dispersal and recruitment from a seed bank, whereas neighboring permanent kettle holes have a more stable local species diversity.}, language = {en} } @article{LozadaGobilardStangPirhoferWalzletal.2019, author = {Lozada Gobilard, Sissi Donna and Stang, Susanne and Pirhofer-Walzl, Karin and Kalettka, Thomas and Heinken, Thilo and Schr{\"o}der, Boris and Eccard, Jana and Jasmin Radha, Jasmin}, title = {Environmental filtering predicts plant-community trait distribution and diversity}, series = {Ecology and Evolution}, journal = {Ecology and Evolution}, publisher = {John Wiley \& Sons, Inc.}, address = {Hoboken}, issn = {2045-7758}, doi = {10.1002/ece3.4883}, pages = {13}, year = {2019}, abstract = {Meta-communities of habitat islands may be essential to maintain biodiversity in anthropogenic landscapes allowing rescue effects in local habitat patches. To understand the species-assembly mechanisms and dynamics of such ecosystems, it is important to test how local plant-community diversity and composition is affected by spatial isolation and hence by dispersal limitation and local environmental conditions acting as filters for local species sorting. We used a system of 46 small wetlands (kettle holes)—natural small-scale freshwater habitats rarely considered in nature conservation policies—embedded in an intensively managed agricultural matrix in northern Germany. We compared two types of kettle holes with distinct topographies (flatsloped, ephemeral, frequently plowed kettle holes vs. steep-sloped, more permanent ones) and determined 254 vascular plant species within these ecosystems, as well as plant functional traits and nearest neighbor distances to other kettle holes. Differences in alpha and beta diversity between steep permanent compared with ephemeral flat kettle holes were mainly explained by species sorting and niche processes and mass effect processes in ephemeral flat kettle holes. The plant-community composition as well as the community trait distribution in terms of life span, breeding system, dispersal ability, and longevity of seed banks significantly differed between the two habitat types. Flat ephemeral kettle holes held a higher percentage of non-perennial plants with a more persistent seed bank, less obligate outbreeders and more species with seed dispersal abilities via animal vectors compared with steep-sloped, more permanent kettle holes that had a higher percentage of wind-dispersed species. In the flat kettle holes, plant-species richness was negatively correlated with the degree of isolation, whereas no such pattern was found for the permanent kettle holes. Synthesis: Environment acts as filter shaping plant diversity (alpha and beta) and plant-community trait distribution between steep permanent compared with ephemeral flat kettle holes supporting species sorting and niche mechanisms as expected, but we identified a mass effect in ephemeral kettle holes only. Flat ephemeral kettle holes can be regarded as meta-ecosystems that strongly depend on seed dispersal and recruitment from a seed bank, whereas neighboring permanent kettle holes have a more stable local species diversity.}, language = {en} } @article{LiangHeinrichSimardetal.2013, author = {Liang, Wei and Heinrich, Ingo and Simard, Sonia and Helle, Gerhard and Linan, Isabel Dorado and Heinken, Thilo}, title = {Climate signals derived from cell anatomy of Scots pine in NE Germany}, series = {Tree physiology}, volume = {33}, journal = {Tree physiology}, number = {8}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0829-318X}, doi = {10.1093/treephys/tpt059}, pages = {833 -- 844}, year = {2013}, abstract = {Tree-ring chronologies of Pinus sylvestris L. from latitudinal and altitudinal limits of the species distribution have been widely used for climate reconstructions, but there are many sites within the temperate climate zone, as is the case in northeastern Germany, at which there is little evidence of a clear climate signal in the chronologies. In this study, we developed long chronologies of several cell structure variables (e. g., average lumen area and cell wall thickness) from P. sylvestris growing in northeastern Germany and investigated the influence of climate on ring widths and cell structure variables. We found significant correlations between cell structure variables and temperature, and between tree-ring width and relative humidity and vapor pressure, respectively, enabling the development of robust reconstructions from temperate sites that have not yet been realized. Moreover, it has been shown that it may not be necessary to detrend chronologies of cell structure variables and thus low-frequency climate signals may be retrieved from longer cell structure chronologies. The relatively extensive resource of archaeological material of P. sylvestris covering approximately the last millennium may now be useful for climate reconstructions in northeastern Germany and other sites in the temperate climate zone.}, language = {en} } @article{LiangHeinrichHelleetal.2013, author = {Liang, Wei and Heinrich, Ingo and Helle, Gerhard and Linan, Isabel Dorado and Heinken, Thilo}, title = {Applying CLSM to increment core surfaces for histometric analyses a novel advance in quantitative wood anatomy}, series = {Dendrochronologia : an interdisciplinary journal of tree-ring science}, volume = {31}, journal = {Dendrochronologia : an interdisciplinary journal of tree-ring science}, number = {2}, publisher = {Elsevier}, address = {Jena}, issn = {1125-7865}, doi = {10.1016/j.dendro.2012.09.002}, pages = {140 -- 145}, year = {2013}, abstract = {A novel procedure has been developed to conduct cell structure measurements on increment core samples of conifers. The procedure combines readily available hardware and software equipment. The essential part of the procedure is the application of a confocal laser scanning microscope (CLSM) which captures images directly from increment cores surfaced with the advanced WSL core-microtome. Cell wall and lumen are displayed with a strong contrast due to the monochrome black and green nature of the images. Consecutive images are merged into long images representing entire increment cores which are then analysed for cell structures in suitable software.}, language = {en} } @article{LemkeKolbGraaeetal.2015, author = {Lemke, Isgard H. and Kolb, Annette and Graae, Bente J. and De Frenne, Pieter and Acharya, Kamal P. and Blandino, Cristina and Brunet, Jorg and Chabrerie, Olivier and Cousins, Sara A. O. and Decocq, Guillaume and Heinken, Thilo and Hermy, Martin and Liira, Jaan and Schmucki, Reto and Shevtsova, Anna and Verheyen, Kris and Diekmann, Martin}, title = {Patterns of phenotypic trait variation in two temperate forest herbs along a broad climatic gradient}, series = {Plant ecology : an international journal}, volume = {216}, journal = {Plant ecology : an international journal}, number = {11}, publisher = {Springer}, address = {Dordrecht}, issn = {1385-0237}, doi = {10.1007/s11258-015-0534-0}, pages = {1523 -- 1536}, year = {2015}, abstract = {Phenotypic trait variation plays a major role in the response of plants to global environmental change, particularly in species with low migration capabilities and recruitment success. However, little is known about the variation of functional traits within populations and about differences in this variation on larger spatial scales. In a first approach, we therefore related trait expression to climate and local environmental conditions, studying two temperate forest herbs, Milium effusum and Stachys sylvatica, along a similar to 1800-2500 km latitudinal gradient. Within each of 9-10 regions in six European countries, we collected data from six populations of each species and recorded several variables in each region (temperature, precipitation) and population (light availability, soil parameters). For each plant, we measured height, leaf area, specific leaf area, seed mass and the number of seeds and examined environmental effects on within-population trait variation as well as on trait means. Most importantly, trait variation differed both between and within populations. Species, however, differed in their response. Intrapopulation variation in Milium was consistently positively affected by higher mean temperatures and precipitation as well as by more fertile local soil conditions, suggesting that more productive conditions may select for larger phenotypic variation. In Stachys, particularly light availability positively influenced trait variation, whereas local soil conditions had no consistent effects. Generally, our study emphasises that intra-population variation may differ considerably across larger scales-due to phenotypic plasticity and/or underlying genetic diversity-possibly affecting species response to global environmental change.}, language = {en} } @article{KurzeHeinkenFartmann2018, author = {Kurze, Susanne and Heinken, Thilo and Fartmann, Thomas}, title = {Nitrogen enrichment in host plants increases the mortality of common Lepidoptera species}, series = {Oecologia}, volume = {188}, journal = {Oecologia}, number = {4}, publisher = {Springer}, address = {New York}, issn = {0029-8549}, doi = {10.1007/s00442-018-4266-4}, pages = {1227 -- 1237}, year = {2018}, abstract = {The recent decline of Lepidoptera species strongly correlates with the increasing intensification of agriculture in Western and Central Europe. However, the effects of changed host-plant quality through agricultural fertilization on this insect group remain largely unexplored. For this reason, we tested the response of six common butterfly and moth species to host-plant fertilization using fertilizer quantities usually applied in agriculture. The larvae of the study species Coenonympha pamphilus, Lycaena phlaeas, Lycaena tityrus, Pararge aegeria, Rivula sericealis and Timandra comae were distributed according to a split-brood design to three host-plant treatments comprising one control treatment without fertilization and two fertilization treatments with an input of 150 and 300kgNha(-1)year(-1), respectively. In L.tityrus, we used two additional fertilization treatments with an input of 30 and 90kgNha(-1)year(-1), respectively. Fertilization increased the nitrogen concentration of both host-plant species, Rumex acetosella and Poa pratensis, and decreased the survival of larvae in all six Lepidoptera species by at least one-third, without clear differences between sorrel- and grass-feeding species. The declining survival rate in all species contradicts the well-accepted nitrogen-limitation hypothesis, which predicts a positive response in species performance to dietary nitrogen content. In contrast, this study presents the first evidence that current fertilization quantities in agriculture exceed the physiological tolerance of common Lepidoptera species. Our results suggest that (1) the negative effect of plant fertilization on Lepidoptera has previously been underestimated and (2) that it contributes to the range-wide decline of Lepidoptera.}, language = {en} } @article{KurzeHeinkenFartmann2017, author = {Kurze, Susanne and Heinken, Thilo and Fartmann, Thomas}, title = {Nitrogen enrichment of host plants has mostly beneficial effects on the life-history traits of nettle-feeding butterflies}, series = {Acta oecologica : international journal of ecology}, volume = {85}, journal = {Acta oecologica : international journal of ecology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1146-609X}, doi = {10.1016/j.actao.2017.11.005}, pages = {157 -- 164}, year = {2017}, abstract = {Butterflies rank among the most threatened animal groups throughout Europe. However, current population trends differ among species. The nettle-feeding butterflies Aglais io and Aglais urticae cope successfully with the anthropogenic land-use change. Both species are assumed to be pre-adapted to higher nitrogen contents in their host plant, stinging nettle (Urtica dioica). However, it is currently unknown, whether this pre-adaptation enables both Aglais species to cope successfully or even to benefit from the excessive nitrogen availabilities in nettles growing in modern farmlands. For this reason, this study focused on the response of both Aglais species to unfertilized nettles compared to nettles receiving 150 or 300 kg N ha(-1) yr(-1) (i.e., common fertilizer quantities of modern-day agriculture). Fertilized nettles were characterized by higher nitrogen concentrations and lower C:N ratios compared to the control group. In both Aglais species, the individuals feeding on fertilized nettles had higher survival rates, shorter larval periods and heavier pupae and, in A. urticae also longer forewings. All these trait shifts are beneficial for the individuals, lowering their risk to die before reproduction and increasing their reproductive potential. These responses agree with the well-accepted nitrogen-limitation hypothesis predicting a positive relationship between the nitrogen content of the diet and the performance of herbivorous insects. Furthermore, our findings suggest that the increasing abundance of both Aglais species may result not only from the increasing spread of nettles into the farmland but also from changes in their quality due to the eutrophication of the landscape during recent decades.}, language = {en} } @article{KruseSteinBachingerGottwaldetal.2016, author = {Kruse, Michaela and Stein-Bachinger, Karin and Gottwald, Frank and Schmidt, Elisabeth and Heinken, Thilo}, title = {Influence of grassland management on the biodiversity of plants and butterflies on organic suckler cow farms}, series = {Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft}, volume = {37}, journal = {Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft}, publisher = {Floristisch-Soziologische Arbeitsgemeinschaft}, address = {G{\"o}ttingen}, issn = {0722-494X}, doi = {10.14471/2016.56.006}, pages = {97 -- 119}, year = {2016}, abstract = {The intensification of agricultural practices has led to a severe decrease in grassland biodiversity. Although there is strong evidence that organic farming can reduce the negative impacts of land use, knowledge regarding the most beneficial management system for species richness on organic grasslands is still scarce. This study examines differences in the biodiversity of plants and butterflies on rotationally and continuously grazed pastures as well as on meadows cut twice per year on two large organic suckler cow farms in NE Germany. Vegetation and flower abundance, as factors likely to influence butterfly abundance and diversity, were compared and used to explain the differences. The data attained by vegetation assessments and monthly transect inspections from May to August were analyzed using descriptive statistics and nonparametric methods. The abiotic site conditions of the studied plots had more influence on plant species numbers than the management method. Dry and nutrient-poor areas (mainly poor types of Cynosurion) and undrained wet fens (Calthion) were important for phytodiversity, measured by the absolute number of species, indicator species for ecologically valuable grasslands and the Shannon Index. Meadows tended to have more indicator species than pastures, where small-scale special sites such as wet depressions were crucial for plant diversity. Butterfly diversity was very low, and 90\% of the recorded butterflies were individuals of the generalist species Pieris napi. Butterfly abundance depended mainly on occurrence of specific habitat types and specific larval host plants. Supply of flowers was crucial only in certain time periods. Differences in butterfly abundance between the management systems could be explained by the site conditions of the studied grasslands. We conclude that meadows are more favorable to support ecologically valuable plant species; however, their extension is contradictory to the organic farming method of suckler cows maintained outside of stables. Rotationally grazed pastures could be a compromise that would enhance the temporal heterogeneity of flower abundance and vegetation structure. The plant diversity on pastures should be improved by less intensive grazing on special sites and plant species enrichment by means of hay transfer. For enhancing butterfly diversity we suggest to reduce land use intensity especially on poor soils. Considering the economic perspective of the farms, small parts of the agricultural area could be sufficient if connectivity to other suitable habitats is assured. Flower abundance and diversity of larval host plants could be promoted by high diversity of farming practices as well as preserving small uncut strips of meadows.}, language = {en} } @article{HeinkenZippel2004, author = {Heinken, Thilo and Zippel, Elke}, title = {Natural re-colonization of experimental gaps by terricolous bryophytes in Central European pine forests}, issn = {0029-5035}, year = {2004}, abstract = {In northeastern German pine forests we studied re-colonization patterns of experimental gaps by four dominant bryophyte species (Dicranum scoparium, Hypnum jutlandicum, Pleurozium schreberi and Scleropodium purum) over three years. Both vegetation and litter layer were removed on 1 m(2) plots within +/- pure colonies of the experimental species, while the humus layer was left intact. All plots were vegetatively re-colonized by the species which was dominant before gap creation. Three mechanisms of re-colonization occurred and interacted: (1) advance of surrounding shoots from the edge into the gaps by clonal growth, (2) dispersal of detached single shoots as well as larger clumps of multiple shoots into the plots, resulting in new colonies by continuing growth, and (3) regeneration from a soil diaspore bank consisting of seemingly dead stem fragments in the humus layer of the gaps. Scleropodium purum, which occurs at locations with good water and nutrient supply, displayed the most rapid growth. Here, some plots were completely recovered after three years. Despite lower rates of advance from the edge, colonization of Hypnum jutlandicum was faster than and of Dicranum scoparium as fast than that of Pleurozium schreberi because of a larger diaspore bank. Thus, each bryophyte species was characterized by a different habitat occupation strategy. The different clonal colonization strategies account for the high competitive capacity and regeneration potential of the investigated bryophyte species in pine forests despite of the lack of generative reproduction. Experimental disturbance resulted in a temporary increase of bryophyte diversity, because short-lived Colonists with a low competitive capacity colonized the gaps, before they will be overgrown by the dominant Perennials}, language = {en} } @article{HeinkenWeber2013, author = {Heinken, Thilo and Weber, Ewald}, title = {Consequences of habitat fragmentation for plant species do we know enough?}, series = {Perspectives in plant ecology, evolution and systematics}, volume = {15}, journal = {Perspectives in plant ecology, evolution and systematics}, number = {4}, publisher = {Elsevier}, address = {Jena}, issn = {1433-8319}, doi = {10.1016/j.ppees.2013.05.003}, pages = {205 -- 216}, year = {2013}, abstract = {Habitat fragmentation is one of the most important causes for the decline of plant species. However, plants differing in phylogeny, habitat requirements and biology are likely to respond differently to habitat fragmentation. We ask whether case studies on the effects of habitat fragmentation conducted so far allow generalizations about its effects on the fitness and genetic diversity of populations of endangered plant species. We compared the characteristics of plant species endangered in Germany whose sensitivity to habitat fragmentation had been studied with those of the endangered species that had not been studied. We found strong discrepancies between the two groups with regard to their taxonomy and traits relevant to their sensitivity to habitat fragmentation. Monocots, graminoids, clonal, abiotically pollinated and self compatible species were underrepresented among the studied species, and most study species were from a few habitat types, in particular grasslands. We conclude that our current knowledge of the effects of habitat fragmentation on plant populations is not sufficient to provide widely applicable guidelines for species management. The selection of species studied so far has been biased toward species from certain habitats and species exhibiting traits that probably make them vulnerable to habitat fragmentation. Future studies should include community-wide approaches in different habitats, e.g. re-visitation studies in which the species pool is assessed at different time intervals, and population-biological studies of species from a wide range of habitats, and of different life forms and growth strategies. A more representative picture of the effects of habitat fragmentation would allow a better assessment of threats and more specific recommendations for optimally managing populations of endangered plants.}, language = {en} } @article{HeinkenSchmidtvonOheimbetal.2006, author = {Heinken, Thilo and Schmidt, Marcus and von Oheimb, Goddert and Kriebitzsch, Wolf-Ulrich and Ellenberg, Hermann}, title = {Soil seed banks near rubbing trees indicate dispersal of plant species into forests by wild boar}, issn = {1439-1791}, doi = {10.1016/j.baae.2005.04.006}, year = {2006}, abstract = {Current knowledge about processes that generate long-distance dispersal of plants is still limited despite its importance for persistence of populations and colonization of new potential habitats. Today wild Large mammals are presumed to be important vectors for long-distance transport of diaspores within and between European temperate forest patches, and in particular wild boars recently came into focus. Here we use a specific habit of wild boar, i.e. wallowing in mud and subsequent rubbing against trees, to evaluate epizoochorous dispersal of vascular plant diaspores. We present soil seed bank data from 27 rubbing trees versus 27 control trees from seven forest areas in Germany. The mean number of viable seeds and the plant species number were higher in soil samples near rubbing trees compared with control trees. Ten of the 20 most frequent species were more frequent, and many species exclusively appeared in the soil samples near rubbing trees. The large number of plant species and seeds - more than 1000 per tree - in the soils near rubbing trees is difficult to explain unless the majority were dispersed by wild boar. Hooked and bristly diaspores, i.e. those adapted to epizoochory, were more frequent; however, many species with unspecialized diaspores occurred exclusively near rubbing trees. As opposed to plant species closely tied to forests species which occur both in forest and open vegetation and non-forest species were more frequent near rubbing trees compared with controls. These findings are consistent with previous studies on diaspore loads in the coats and hooves of shot wild boars. However, our method allows to identify the transport of diaspores from the open landscape into forest stands, where they might especially emerge after disturbance, and a clustered distribution of epizoochorically dispersed seeds. Moreover, accumulation of seeds of wetness indicators near rubbing trees demonstrates directed dispersal of plant species inhabiting wet places among remote wallows.}, language = {en} } @article{HeinkenSchmidtvonOheimbetal.2005, author = {Heinken, Thilo and Schmidt, M. and von Oheimb, Goddert and Kriebitzsch, Wolf-Ulrich and Ellenberg, H.}, title = {Ausbreitung von Pflanzen durch Schalenwild}, issn = {0936-1294 -}, year = {2005}, language = {de} } @article{HeinkenRohnerHoppert2007, author = {Heinken, Thilo and Rohner, Maria-Sofie and Hoppert, Michael}, title = {Red wood ants (Formica rufa group) disperse bryophyte and lichen fragments on a local scale}, issn = {0078-2238}, year = {2007}, abstract = {Gametophyte and thallus fragments, respectively, may be an important or even the only mode of reproduction for many bryophytes and lichens species. Until now especially birds and mammals have been identifi ed as potential animal dispersal vectors of fragments. This study investigates the dispersal of bryophyte and lichen fragments by red wood ants which build large nest mounds from plant material and are abundant in European coniferous forests. We sampled nest material from 25 nest mounds in fi ve different pine and spruce forest types in Germany and found numerous fragments of 20 bryophyte and ten lichen species. As they occurred on almost all studied mounds and often in large numbers we conclude that collecting cryptogam fragments as nest material is a characteristic feature for the Formica rufa group in coniferous forests. Species number and composition of fragments on mounds coincided with the epigeic vegetation around ant nests to a large extent: Almost all collected species were present in the vegetation, and dominant fragment species occurred in large amounts in the vicinity of ant nests. Lichen fragments were larger than bryophyte fragments. Certain life forms (weft-forming bryophytes, reindeer lichens) were accumulated on mounds, while others (tall turfs, cup-type Cladonia species) were discriminated, refl ecting fragmentation features of species. Collected fragments may regenerate to mature plants if nest mounds are abandoned, and especially if they are lost during transport over several metres. We conclude that dispersal of fragments by red wood ants contributes to maintain epigeic bryophyte and lichen diversity of coniferous forests by supporting colonisation after disturbances, which occur on different spatial and temporal scales.}, language = {en} } @article{Heinken2008, author = {Heinken, Thilo}, title = {Vegetation und Standort bodensaurer Buchenw{\"a}lder am Arealrand : am Beispiel Mittelbrandenburgs}, issn = {0018-0637}, year = {2008}, abstract = {Different from NW Germany, the northern part of NE Germany and the "Hohe Flaeming" region, central Brandenburg is considered as being largely devoid of natural beech forests because of its subcontinental, dry climate. In the present study the vegetation ecology of beech forests of the region is comprehensively documented for the first time, and they are compared with NW German stands in Lower Saxony. In the study area beech forests are concentrated in the Berlin-Potsdam region along the Havel river lakes which is characterised by relatively high precipitation and a specific land use history. All belong to the Luzulo-Fagetum growing on acid soils. Four subtypes are distinguished according to nutrient availability and soil moisture. The central Brandenburg Luzulo-Fagetum does not markedly deviate from other beech forests in the northern German lowlands with respect to vegetation structure and edaphic subtypes. However, numerous indicator species for humid or moist conditions are less frequent than under atlantic climate conditions in the lowlands of Lower Saxony, a pattern occurring also in other forest communities. On the other hand, nitrogen and disturbance indicators are more frequent in central Brandenburg. As expected, podzolisation of the soils and humus accumulation is lower in beech forests under subcontinental climate, but surprisingly the soils are more sandy and thus drier. However, beech forests are lacking on south-exposed slopes, and they are notably occurring in northern exposition. A combined analysis of distribution patterns and climatic data, postglacial vegetation history and forest use history, and actual rejuvenation dynamics reveals that the present-day beech forests in central Brandenburg have to be considered as near-natural relics, which are currently spreading. The range of potentially natural beech forests is larger than assumed until now, but further on it is not clearly to define.}, language = {de} } @article{Heinken2009, author = {Heinken, Thilo}, title = {Populationsbiologische und genetische Konsequenzen von Habitatfragmentierung bei Pflanzen : wissenschaftliche Grundlagen f{\"u}r Biotopverbundsysteme}, issn = {0722-494X}, year = {2009}, abstract = {Besides habitat loss, population-biological and genetic consequences of habitat fragmentation are thought to be a major threat to species since the 1990's and thus are now in the focus of plant species conservation. Using examples, this article gives an overview on the state of the art. It aims to evaluate the relevance habitat fragmentation and the resulting small size and isolation of populations may have for Central European plant populations. Stochasticity, edge effects, pollinator limitation, genetic drift and inbreeding depression are identified as important and very widespread negative effects. Together with changed habitat quality due to eutrophication, drainage or altered land use they negatively affect the fitness of individuals and populations, resulting in an increased risk of extinction. This negative effect of small populations on the fitness of individuals is called the Allee-effect, irrespective of the underlying causes, which can only be identified by scientific experiments. Metapopulation dynamics that are supported by a habitat network may prevent a permanent extinction of plant populations and minimize the negative genetic effects of habitat fragmentation by increasing gene flow via pollen and seeds. However, existing studies from Central Europe mainly concentrated on certain plant families (Gentianaceae, Primulaceae), habitats (species- rich grasslands), insect-pollinated and outcrossing species, and species mainly relying on sexual reproduction. On the other hand, few insights exist about grasses, ruderal plants and weeds, non-indigenous, wind- and self-pollinated species, and species mainly reproducing vegetatively or via apomictic seeds. However, according to the present state of knowledge especially these plant species, and those with a high dispersal potential, have to be considered as less sensitive to habitat fragmentation. Based on these findings, habitat types are classified with regard to their sensitivity to fragmentation, and ecological characters and species traits of sensitive and less sensitive species are compared. Finally, general consequences for conservation practice are presented with regard to target species and habitats for the formation of habitat networks, minimum viable population sizes, genetic rescue of populations, and deploying plants from ex-situ conservation to natural habitats.}, language = {de} } @article{Heinken2008, author = {Heinken, Thilo}, title = {Welche populationsbiologischen und genetischen Konsequenzen hat Habitatfragmentierung f{\"u}r Pflanzen? : Wissenschaftliche Grundlagen f{\"u}r ein Biotopverbundsystem f{\"u}r Pflanzen in Brandenburg}, issn = {0942-9328}, year = {2008}, abstract = {Neben dem Habitatverlust gelten Konsequenzen der Habitatfragmentierung seit den 1990er Jahren als wesentliche Ursache der Gefaehrdung von Pflanzen und stehen damit nun auch im Fokus des botanischen Artenschutzes. Der vorliegende Beitrag gibt einen ueberblick ueber den Stand der populationsbiologischen und genetischen Forschung und versucht abzuschaetzen, welche Bedeutung Habitatfragmentierung und die dadurch entstehenden kleinen, isolierten Populationen auf heimische Pflanzenarten haben koennen. Als wesentliche und offenbar sehr weit verbreitete negative Effekte werden Zufallsereignisse, Randeffekte, Bestaeuberlimitierung, Gendrift und Inzuchtdepression identifiziert. Zusammen mit verringerter Habitatqualitaet durch Eutrophierung, Entwaesserung oder Nutzungsaenderung wirken sie zumeist negativ auf die Fitness der Individuen und Populationen und erhoehen so deren Aussterberisiko. Dieser negative Effekt kleiner Populationen auf die individuelle Fitness wird unabhaengig von der Ursache als Allee-Effekt bezeichnet. Eine durch einen Biotopverbund gefoerderte Metapopulationsdynamik kann das dauerhafte Aussterben von Pflanzenpopulationen verhindern und mindert die negativen genetischen Effekte der Habitatfragmentierung ueber einen erhoehten Genfluss durch Pollen und Samen. Die bisherigen wissenschaftlichen Studien in Mitteleuropa beruhen allerdings in ueberproportionaler Weise auf bestimmten Pflanzenfamilien (Gentianaceae, Primulaceae), Habitaten (Trocken- und Magerrasen, Wirtschaftsgruenland), insekten- und obligat fremdbestaeubten sowie weitgehend auf sexuelle Fortpflanzung angewiesenen Arten, waehrend etwa ueber Grasartige, Ruderalpflanzen, wind- und selbstbestaeubte sowie an vegetative Fortpflanzung angepasste Arten nur wenige Erkenntnisse vorliegen. Gerade diese und Pflanzenarten mit hohem Ausbreitungspotenzial muessen aber nach derzeitigem Wissensstand als weniger sensitiv gegenueber Habitatfragmentierung eingestuft werden. Auf diesen Befunden aufbauend werden fuer die Naturschutzpraxis Biotoptypen hinsichtlich ihrer Sensitivitaet gegenueber Habitatfragmentierung klassifiziert und ein auf biologischen Merkmalen basierender Kriterienkatalog zur Auswahl von Zielarten des Biotopverbunds vorgestellt. Schließlich wird eroertert, was bei Maßnahmen zur Regeneration kleiner bzw. bereits ausgestorbener Populationen zu beachten ist, und es werden allgemeine Folgerungen zur Ausgestaltung eines Biotopverbundskonzepts fuer Pflanzen gezogen.}, language = {de} } @article{HeimHoelzelHeinkenetal.2019, author = {Heim, Ramona J. and H{\"o}lzel, Norbert and Heinken, Thilo and Kamp, Johannes and Thomas, Alexander and Darman, Galina F. and Smirenski, Sergei M. and Heim, Wieland}, title = {Post-burn and long-term fire effects on plants and birds in floodplain wetlands of the Russian Far East}, series = {Biodiversity and conservation}, volume = {28}, journal = {Biodiversity and conservation}, number = {6}, publisher = {Springer}, address = {Dordrecht}, issn = {0960-3115}, doi = {10.1007/s10531-019-01746-3}, pages = {1611 -- 1628}, year = {2019}, abstract = {Wildfires affect biodiversity at multiple levels. While vegetation is directly changed by fire events, animals are often indirectly affected through changes in habitat and food availability. Globally, fire frequency and the extent of fires are predicted to increase in the future. The impact of fire on the biodiversity of temperate wetlands has gained little attention so far. We compared species richness and abundance of plants and birds in burnt and unburnt areas in the Amur floodplain/Russian Far East in the year of fire and 1 year after. We also analysed vegetation recovery in relation to time since fire over a period of 18 years. Plant species richness was higher in burnt compared to unburnt plots in the year of the fire, but not in the year after. This suggests that fire has a positive short-term effect on plant diversity. Bird species richness and abundance were lower on burnt compared to unburnt plots in the year of the fire, but not in the year after. Over a period of 18 years, high fire frequency led to an increase in herb cover and a decrease in grass cover. We show that the effects on biodiversity are taxon- and species-specific. Fire management strategies in temperate wetlands should consider fire frequency as a key driving force of vegetation structure, with carry-over effects on higher trophic levels. Designing fire refuges, i.e., areas that do not burn annually, might locally be necessary to maintain high species richness.}, language = {en} } @article{GuentherSchmidtQuittetal.2021, author = {G{\"u}nther, Kerstin and Schmidt, Marcus and Quitt, Heinz and Heinken, Thilo}, title = {Ver{\"a}nderungen der Waldvegetation im Elbe-Havelwinkel von 1960 bis 2015}, series = {Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft}, journal = {Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft}, number = {41}, publisher = {Floristisch-Soziologische Arbeitsgemeinschaft}, address = {G{\"o}ttingen}, issn = {0722-494X}, doi = {10.14471/2021.41.005}, pages = {53 -- 85}, year = {2021}, abstract = {Forest ecosystems are subject to a variety of influences such as forest management, nitrogen deposition, changes in the groundwater level or the immigration of invasive species. The repetition of historical releves is an important means of documenting the resulting changes in plant communities and determining their main drivers. In 2015, we examined the vegetation change in 140 semi-permanent plots in managed forests in the Elbe valley in the NE German lowlands (Saxony-Anhalt, Brandenburg). The first survey took place from 1956 to 1963. The releves cover an almost uniquely broad spectrum of different site conditions, ranging from wet forests (alluvial, swamp and bog forests of Alnion incanae, Alnion glutinosae and Betulion pubescentis) to acidic mixed oak forests (Quercion roboris) up to acidic, mostly dry pine forests with different nutrient status (Dicrano-Pinion). We analyzed the changes in the vegetation with the help of forest stand data, winner and loser species, alpha- and beta-diversity as well as the Ellenberg indicator values for nitrogen, reaction, moisture and light. In contrast to previous resurvey studies, areas were also taken into account on which a complete change of forest stand had taken place before the second survey. Particularly in the wet forests and acidic forests with a moderately good nutrient supply, changes in the main tree species have been recorded, and many pine stands have been newly established in the meantime. The species richness has decreased overall and in almost all forest types, but the beta-diversity has remained unchanged or has increased. The Ellenberg values indicate a decrease in soil moisture in the wet forests, while the acidic pine forests in particular have become darker, richer in nutrients and more humid. The number of loser species is more than twice as high as that of the winner species, but with different developments in the individual forest types. In particular, the wet forests, the acidic mixed oak forests and the lichen-pine forests have lost most of their characteristic species. The resurvey after more than 50 years shows a different development of the individual forest types. Vegetation changes in the wet forests are mainly due to local groundwater level drawdown and the resulting increased availability of nutrients. The alluvial forests were also strongly influenced by forest interventions. The reasons for the trend towards more humid and more nutrient-rich conditions in formerly dry acidic pine and oak forests are nitrogen depositions and a succession after the abandonment of historical forms of forest use (litter raking, forest pasture). Although the individual forest types have developed differently, eutrophication, falling groundwater levels and silviculture are the most important causes for the changes in vegetation. Silvicultural interventions such as clear cutting and stand conversion with a change of tree species are at the same time the main reason why the vegetation has not been homogenized despite the leveling of the site gradient as measured by the beta-diversity.}, language = {de} } @article{GraaeVerheyenKolbetal.2009, author = {Graae, Bente Jessen and Verheyen, Kris and Kolb, Annette and van der Veken, Sebastian and Heinken, Thilo and Chabrerie, Olivier and Diekmann, Martin and Valtinat, Karin and Zindel, Renate and Karlsson, Elisabeth and Str{\"o}m, Lotta and Decocq, Guillaume and Hermy, Martin and Baskin, Carol C.}, title = {Germination requirements and seed mass of slow- and fast-colonizing temperate forest herbs along a latitudinal gradient}, issn = {1195-6860}, doi = {10.2980/16-2-3234}, year = {2009}, abstract = {Predictions on displacement of suitable habitats due to climate change suggest that plant species with poor colonization ability may be unable to move fast enough to match forecasted climate-induced changes in habitat distribution. However, studies on early Holocene plant migration show fast migration of many plant species that are poor colonizers today. We hypothesize that warmer temperatures during the early Holocene yielded higher seed quality, contributing to explaining the fast migration. We studied how the 3 seed quality variables, seed mass, germinability, and requirements for break of seed dormancy, vary for seeds of 11 forest herb species with varying colonization capacity collected along a 1400-km latitudinal gradient. Within species, seed mass showed a positive correlation with latitude, whereas germinability was more positively correlated with temperature (growing degree hours obtained at time of seed collection). Only slow-colonizing species increased germinability with temperature, whereas only fast-colonizing species increased germinability with latitude. These interactions were only detectable when analyzing germinability of the seeds, even though this trait and seed mass were correlated. The requirement for dormancy break did not correlate with latitude or temperature. The results indicate that seed development of slow colonizers may be favoured by a warmer climate, which in turn may be important for their migration capacity.}, language = {en} } @article{GraaeDeFrenneKolbetal.2012, author = {Graae, Bente J. and De Frenne, Pieter and Kolb, Annette and Brunet, Jorg and Chabrerie, Olivier and Verheyen, Kris and Pepin, Nick and Heinken, Thilo and Zobel, Martin and Shevtsova, Anna and Nijs, Ivan and Milbau, Ann}, title = {On the use of weather data in ecological studies along altitudinal and latitudinal gradients}, series = {Oikos}, volume = {121}, journal = {Oikos}, number = {1}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0030-1299}, doi = {10.1111/j.1600-0706.2011.19694.x}, pages = {3 -- 19}, year = {2012}, abstract = {Global warming has created a need for studies along climatic gradients to assess the effects of temperature on ecological processes. Altitudinal and latitudinal gradients are often used as such, usually in combination with air temperature data from the closest weather station recorded at 1.52 m above the ground. However, many ecological processes occur in, at, or right above the soil surface. To evaluate how representative the commonly used weather station data are for the microclimate relevant for soil surface biota, we compared weather station temperatures for an altitudinal (500900 m a.s.l.) and a latitudinal gradient (4968 degrees N) with data obtained by temperature sensors placed right below the soil surface at five sites along these gradients. The mean annual temperatures obtained from weather stations and adjusted using a lapse rate of -5.5 degrees C km-1 were between 3.8 degrees C lower and 1.6 degrees C higher than those recorded by the temperature sensors at the soil surface, depending on the position along the gradients. The monthly mean temperatures were up to 10 degrees C warmer or 5 degrees C colder at the soil surface. The within-site variation in accumulated temperature was as high as would be expected from a 300 m change in altitude or from a 4 degrees change in latitude or a climate change scenario corresponding to warming of 1.63.8 degrees C. Thus, these differences introduced by the decoupling are significant from a climate change perspective, and the results demonstrate the need for incorporating microclimatic variation when conducting studies along altitudinal or latitudinal gradients. We emphasize the need for using relevant temperature data in climate impact studies and further call for more studies describing the soil surface microclimate, which is crucial for much of the biota.}, language = {en} } @article{FischerHeinkenMeyeretal.2009, author = {Fischer, Petra and Heinken, Thilo and Meyer, Peter and Schmidt, Marcus and Waesch, Gunnar}, title = {Zur Abgrenzung und Situation des FFH-Lebensraumtyps "Mitteleurop{\"a}ische Flechten-Kiefernw{\"a}lder" (91TO) in Deutschland}, issn = {0028-0615}, year = {2009}, abstract = {Die in Deutschland gegenw{\"a}rtig durch N{\"a}hrstoffeintr{\"a}ge und ausbleibenden N{\"a}hrstoffentzug stark im R{\"u}ckgang begriffenen Flechten-Kiefernw{\"a}lder werden als Biotoptyp wie auch als Lebensraumtyp "Mitteleurop{\"a}ische Flechten-Kiefernw{\"a}lder" (Code 91T0) diskutiert. Die bisherige, sehr uneinheitliche Differenzierung von Flechten-Kiefernw{\"a}ldern auf der Ebene von Biotoptypen wird dargestellt. Auf der Grundlage neuerer vegetationskundlicher {\"u}bersichten werden Vorschl{\"a}ge f{\"u}r eine einheitliche Abgrenzung des Biotoptyps "Flechten-Kiefernwald" und des Lebensraumtyps 91T0 unterbreitet. Im nieders{\"a}chsischen Naturwaldreservat "Kaarßer Sandberge" (Niedersachsen) wurde die Anwendung des Konzeptes erfolgreich erprobt. Nicht nur hier, sondern auch deutschlandweit wird der R{\"u}ckgang der Erdflechten in den Kieferw{\"a}ldern zugunsten von Drahtschmiele und/ oder pleurokarpen Moosen deutlich. Nach der derzeitigen Definition des Lebensraumtyps 91T0 besteht auf der Grundlage der FFH-Richtlinie nicht f{\"u}r alle Flechten-Kiefernw{\"a}lder eine Chance der Verbesserung. Der Ausschluss von außerhalb des nat{\"u}rlichen Verbreitungsgebietes der Wald-Kiefer gelegenen sowie von durch Aufforstung angepflanzten Best{\"a}nden bringt Probleme mit sich, die diskutiert werden. F{\"u}r den Erhalt und die Wiederherstellung der gr{\"o}ßtenteils nutzungsbedingt entstandenen Flechten-Kiefernw{\"a}lder sind praktikable Pflegemaßnahmen notwendig, die im Rahmen von Streunutzungsversuchen erprobt werden m{\"u}ssen.}, language = {de} } @article{DittmannHeinkenSchmidt2018, author = {Dittmann, Thea and Heinken, Thilo and Schmidt, Marcus}, title = {Die W{\"a}lder von Magdeburgerforth (Fl{\"a}ming, Sachsen-Anhalt)}, series = {Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft}, journal = {Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft}, number = {38}, publisher = {Floristisch-Soziologische Arbeitsgemeinschaft}, address = {G{\"o}ttingen}, issn = {0722-494X}, doi = {10.14471/2018.38.009}, pages = {11 -- 42}, year = {2018}, abstract = {In einem rund 2.200 ha großen Waldgebiet bei Magdeburgerforth (Fl{\"a}ming, Sachsen-Anhalt) wurden 1948 bis 1950 von Harro Passarge 120 Vegetationsaufnahmen sowie eine Vegetationskartierung erstellt. Das Gebiet zeichnet sich durch eine große Vielfalt an Waldtypen aus den Verb{\"a}nden Agrostio-Quercion petraeae, Alnion glutinosae, Alnion incanae, Carpinion betuli, Dicrano-Pinion und Quercion roboris aus. Daher und weil viele der heute in W{\"a}ldern wirksamen Prozesse (z. B. Stickstoffeintrag, Klimawandel) vor 60 Jahren noch nicht sp{\"u}rbar waren, bietet sich das Gebiet f{\"u}r eine Wiederholungsuntersuchung besonders an. Da die Aufnahmefl{\"a}chen von Passarge nicht punktgenau verortet waren, wurden im Jahr 2014 in einem {\"u}ber die Forstabteilungen und die Vegetationskarte definierten Suchraum immer die der Erstaufnahme {\"a}hnlichsten Waldbest{\"a}nde erfasst. Insgesamt konnten 97 (81 \%) der Aufnahmen wiederholt werden. Vegetationsver{\"a}nderungen werden mithilfe einer NMDS-Ordination, der Gegen{\"u}berstellung von α -Diversit{\"a}t, Zeigerwerten und Waldbindungskategorien f{\"u}r die beiden Aufnahmezeitpunkte sowie {\"u}ber die Identifikation von Gewinner- und Verlierer-Arten analysiert. Auch wenn methodenbedingt bei der Wiederholungsuntersuchung nur die jeweils geringstm{\"o}gliche Vegetationsver{\"a}nderung abgebildet wird, konnten Ergebnisse erzielt werden, die mit denen quasi permanenter Plots {\"u}bereinstimmen. Die beobachteten allgemeinen Trends (Eutrophierung, Sukzession nach Nutzungswandel, Verlust lichtliebender und magerkeitszeigender Arten, Ausbreitung von stickstoffliebenden Arten und mesophilen Waldarten, Einwanderung von Neophyten, keine generelle Abnahme der Artenzahl) stimmen gut mit den in zahlreichen Studien aus mitteleurop{\"a}ischen W{\"a}ldern festgestellten {\"u}berein. Durch das von nassen bis trockenen sowie von bodensauer-n{\"a}hrstoffarmen bis zu relativ basenreichen B{\"o}den reichende Standortsspektrum innerhalb des Untersuchungsgebietes konnte aber - deutlicher als in den meisten bisherigen Fallstudien - gezeigt werden, dass sich die Resilienz der W{\"a}lder gegen{\"u}ber Vegetationsver{\"a}nderung je nach Ausgangsgesellschaft stark unterscheidet und jeweils unterschiedliche Treiber wirksam sind. Stellario-Carpinetum und Luzulo-Quercetum erwiesen sich als relativ stabil, und auch in den Feuchtw{\"a}ldern des Circaeo-Alnetum gab es trotz eines Artenwechsels wenig Hinweise auf Umweltver{\"a}nderungen. Dagegen wiesen die W{\"a}lder n{\"a}hrstoffarmer Standorte (Sphagno-Alnetum, Betulo-Quercetum, Dicrano-Pinion) viele Verliererarten und eine starke Eutrophierungstendenz auf. Die in besonderem Maße von historischen Waldnutzungsformen abh{\"a}ngigen thermophilen W{\"a}lder und die Flechten-Kiefernw{\"a}lder gingen weitgehend verloren.}, language = {de} } @article{DiekmannMuellerHeinkenetal.2015, author = {Diekmann, Martin and M{\"u}ller, Josef and Heinken, Thilo and Dupre, Cecilia}, title = {Survey and statistical analysis of plant reintroductions in Germany}, series = {Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft}, journal = {Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft}, number = {35}, publisher = {Floristisch-Soziologische Arbeitsgemeinschaft}, address = {G{\"o}ttingen}, issn = {0722-494X}, pages = {249 -- 265}, year = {2015}, abstract = {Aim - Plant reintroductions and other forms of targeted species translocations will in the future gain growing importance for nature conservation. In fragmented habitats, species reintroductions offer one of the most efficient tools for preserving or restoring plant diversity. In our study, we have compiled available data about plant reintroduction projects in Germany to answer the following questions: (1) What are the characteristics, habitat preferences and ecological strategies of species considered in plant reintroduction trials, and are these representative of the entire class of threatened species in Germany? (2) Is the judgment of the success or failure of plant reintroductions biased by the choice of species used in the experiments? (3) Do reintroduction efforts focus on those species for which Germany has a particularly high responsibility for conservation? Methods - Information about reintroduction projects in Germany were obtained from published and internet sources as well as unpublished reports. In our search we focused on single-species trials in the framework of scientific or conservation projects. For all threatened species included in our database, we compiled information on their systematics, life form, ecological strategies and habitat preferences. A list of all species being threatened nationally or regionally, comprising both reintroduced and not reintroduced species, served as a reference for statistical analysis. Results - The list of vascular plants used in conservation-oriented reintroductions consisted of 196 taxa. Species of families with large and conspicuous, mostly insect-pollinated flowers (for example, Orchidaceae) were over-represented among the reintroduced species compared to those threatened species not included in reintroduction trials. Species considered were also more often than expected found in semi-natural open habitats such as heathlands and grasslands. Notably, many projects focused on calcareous grasslands, characterized by dry, high-pH and infertile soils. In contrast, species of more near-natural vegetation (alpine and rocky formations, forests) were under-represented. About 25\% of the species that were reintroduced are not threatened on the national scale. Out of 150 species for which Germany has a particularly high responsibility for conservation, only 14 (9.3\%) were reintroduced. For only about 1/3 of all reintroduction attempts, success or failure were documented; whereas the success rate appears to be relatively low in nutrient-poor environments, trials with nutrient-demanding and competitive species were more successful. Conclusions - We conclude that conservation-oriented reintroduction attempts should focus more on species for which the country or a region has a particular high responsibility. Reintroductions, to a larger extent than at present, also need to consider the different chances of success in different habitat types and environments.}, language = {de} } @article{DiekmannAndresBeckeretal.2019, author = {Diekmann, Martin and Andres, Christian and Becker, Thomas and Bennie, Jonathan and Blueml, Volker and Bullock, James M. and Culmsee, Heike and Fanigliulo, Miriam and Hahn, Annett and Heinken, Thilo and Leuschner, Christoph and Luka, Stefanie and Meissner, Justus and M{\"u}ller, Josef and Newton, Adrian and Peppler-Lisbach, Cord and Rosenthal, Gert and van den Berg, Leon J. L. and Vergeer, Philippine and Wesche, Karsten}, title = {Patterns of long-term vegetation change vary between different types of semi-natural grasslands in Western and Central Europe}, series = {Journal of vegetation science}, volume = {30}, journal = {Journal of vegetation science}, number = {2}, publisher = {Wiley}, address = {Hoboken}, issn = {1100-9233}, doi = {10.1111/jvs.12727}, pages = {187 -- 202}, year = {2019}, abstract = {Questions Has plant species richness in semi-natural grasslands changed over recent decades? Do the temporal trends of habitat specialists differ from those of habitat generalists? Has there been a homogenization of the grassland vegetation? Location Different regions in Germany and the UK. Methods We conducted a formal meta-analysis of re-survey vegetation studies of semi-natural grasslands. In total, 23 data sets were compiled, spanning up to 75 years between the surveys, including 13 data sets from wet grasslands, six from dry grasslands and four from other grassland types. Edaphic conditions were assessed using mean Ellenberg indicator values for soil moisture, nitrogen and pH. Changes in species richness and environmental variables were evaluated using response ratios. Results In most wet grasslands, total species richness declined over time, while habitat specialists almost completely vanished. The number of species losses increased with increasing time between the surveys and were associated with a strong decrease in soil moisture and higher soil nutrient contents. Wet grasslands in nature reserves showed no such changes or even opposite trends. In dry grasslands and other grassland types, total species richness did not consistently change, but the number or proportions of habitat specialists declined. There were also considerable changes in species composition, especially in wet grasslands that often have been converted into intensively managed, highly productive meadows or pastures. We did not find a general homogenization of the vegetation in any of the grassland types. Conclusions The results document the widespread deterioration of semi-natural grasslands, especially of those types that can easily be transformed to high production grasslands. The main causes for the loss of grassland specialists are changed management in combination with increased fertilization and nitrogen deposition. Dry grasslands are most resistant to change, but also show a long-term trend towards an increase in more mesotrophic species.}, language = {en} } @article{DeLombaerdeVerheyenPerringetal.2018, author = {De Lombaerde, Emiel and Verheyen, Kris and Perring, Michael P. and Bernhardt-Roemermann, Markus and Van Calster, Hans and Brunet, Jorg and Chudomelova, Marketa and Decocq, Guillaume and Diekmann, Martin and Durak, Tomasz and Hedl, Radim and Heinken, Thilo and Hommel, Patrick and Jaroszewicz, Bogdan and Kopecky, Martin and Lenoir, Jonathan and Macek, Martin and M{\´a}liš, František and Mitchell, Fraser J. G. and Naaf, Tobias and Newman, Miles and Petř{\´i}k, Petr and Reczyńska, Kamila and Schmidt, Wolfgang and Swierkosz, Krzysztof and Vild, Ondrej and Wulf, Monika and Baetena, Lander}, title = {Responses of competitive understorey species to spatial environmental gradients inaccurately explain temporal changes}, series = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, volume = {30}, journal = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, publisher = {Elsevier GMBH}, address = {M{\"u}nchen}, issn = {1439-1791}, doi = {10.1016/j.baae.2018.05.013}, pages = {52 -- 64}, year = {2018}, abstract = {Understorey plant communities play a key role in the functioning of forest ecosystems. Under favourable environmental conditions, competitive understorey species may develop high abundances and influence important ecosystem processes such as tree regeneration. Thus, understanding and predicting the response of competitive understorey species as a function of changing environmental conditions is important for forest managers. In the absence of sufficient temporal data to quantify actual vegetation changes, space-for-time (SFT) substitution is often used, i.e. studies that use environmental gradients across space to infer vegetation responses to environmental change over time. Here we assess the validity of such SFT approaches and analysed 36 resurvey studies from ancient forests with low levels of recent disturbances across temperate Europe to assess how six competitive understorey plant species respond to gradients of overstorey cover, soil conditions, atmospheric N deposition and climatic conditions over space and time. The combination of historical and contemporary surveys allows (i) to test if observed contemporary patterns across space are consistent at the time of the historical survey, and, crucially, (ii) to assess whether changes in abundance over time given recorded environmental change match expectations from patterns recorded along environmental gradients in space. We found consistent spatial relationships at the two periods: local variation in soil variables and overstorey cover were the best predictors of individual species' cover while interregional variation in coarse-scale variables, i.e. N deposition and climate, was less important. However, we found that our SFT approach could not accurately explain the large variation in abundance changes over time. We thus recommend to be cautious when using SFT substitution to infer species responses to temporal changes.}, language = {en} } @article{DeFrenneRodriguezSanchezCoomesetal.2013, author = {De Frenne, Pieter and Rodriguez-Sanchez, Francisco and Coomes, David Anthony and B{\"a}ten, Lander and Verstr{\"a}ten, Gorik and Vellend, Mark and Bernhardt-R{\"o}mermann, Markus and Brown, Carissa D. and Brunet, J{\"o}rg and Cornelis, Johnny and Decocq, Guillaume M. and Dierschke, Hartmut and Eriksson, Ove and Gilliam, Frank S. and Hedl, Radim and Heinken, Thilo and Hermy, Martin and Hommel, Patrick and Jenkins, Michael A. and Kelly, Daniel L. and Kirby, Keith J. and Mitchell, Fraser J. G. and Naaf, Tobias and Newman, Miles and Peterken, George and Petrik, Petr and Schultz, Jan and Sonnier, Gregory and Van Calster, Hans and Waller, Donald M. and Walther, Gian-Reto and White, Peter S. and Woods, Kerry D. and Wulf, Monika and Graae, Bente Jessen and Verheyen, Kris}, title = {Microclimate moderates plant responses to macroclimate warming}, series = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {110}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {46}, publisher = {National Acad. of Sciences}, address = {Washington}, issn = {0027-8424}, doi = {10.1073/pnas.1311190110}, pages = {18561 -- 18565}, year = {2013}, abstract = {Recent global warming is acting across marine, freshwater, and terrestrial ecosystems to favor species adapted to warmer conditions and/or reduce the abundance of cold-adapted organisms (i.e., "thermophilization" of communities). Lack of community responses to increased temperature, however, has also been reported for several taxa and regions, suggesting that "climatic lags" may be frequent. Here we show that microclimatic effects brought about by forest canopy closure can buffer biotic responses to macroclimate warming, thus explaining an apparent climatic lag. Using data from 1,409 vegetation plots in European and North American temperate forests, each surveyed at least twice over an interval of 12-67 y, we document significant thermophilization of ground-layer plant communities. These changes reflect concurrent declines in species adapted to cooler conditions and increases in species adapted to warmer conditions. However, thermophilization, particularly the increase of warm-adapted species, is attenuated in forests whose canopies have become denser, probably reflecting cooler growing-season ground temperatures via increased shading. As standing stocks of trees have increased in many temperate forests in recent decades, local microclimatic effects may commonly be moderating the impacts of macroclimate warming on forest understories. Conversely, increases in harvesting woody biomass-e.g., for bioenergy-may open forest canopies and accelerate thermophilization of temperate forest biodiversity.}, language = {en} } @article{deFrenneKolbVerheyenetal.2009, author = {de Frenne, Pieter and Kolb, Annette and Verheyen, Kris and Brunet, Johanne and Chabrerie, Olivier and Decocq, Guillaume and Diekmann, Martin and Eriksson, Ove and Heinken, Thilo and Hermy, Martin and J{\~o}gar, {\"U}lle and Stanton, Sara and Quataert, Paul and Zindel, Renate and Zobel, Martin and Graae, Bente Jessen}, title = {Unravelling the effects of temperature, latitude and local environment on the reproduction of forest herbs}, issn = {1466-822X}, doi = {10.1111/j.1466-8238.2009.00487.x}, year = {2009}, abstract = {Aim To investigate the effect of temperature, latitude and local environment on the reproductive traits of widespread perennial forest herbs to better understand the potential impacts of rising temperatures on their population dynamics and colonization capacities. Location Six regions along a latitudinal gradient from France to Sweden. Methods Within each region, we collected data from three to five populations of up to six species. For each species, several variables were recorded in each region (temperature, latitude) and population (local abiotic and biotic environmental variables), and seed production and germination were estimated. Resource investment in reproduction (RIR) was quantified as seed number ¥ seed mass, while germinable seed output (GSO) was expressed as seed number ¥ germination percentage.We performed linear regression and mixed effect models to investigate the effects of temperature (growing degree hours), latitude and local abiotic and biotic environment on RIR and GSO. Results Temperature and latitude explained most of the variation in RIR and GSO for early flowering species with a northerly distribution range edge (Anemone nemorosa, Paris quadrifolia and Oxalis acetosella). Reproduction of the more southerly distributed species (Brachypodium sylvaticum, Circaea lutetiana and Primula elatior), in contrast, was independent of temperature/latitude. In the late summer species, B. sylvaticum and C. lutetiana, variation in RIR and GSO was best explained by local environmental variables, while none of the investigated variables appeared to be related to reproduction in P. elatior. Main conclusions We showed that reproduction of only two early flowering, northerly distributed species was related to temperature. This suggests that the potential reproductive response of forest herbs to climate warming partly depends on their phenology and distribution, but also that the response is to some extent species dependent. These findings should be taken into account when predictions about future shifts in distribution range are made.}, language = {en} } @article{deFrenneGraaeKolbetal.2010, author = {de Frenne, Pieter and Graae, Bente Jessen and Kolb, Annette and Brunet, J{\"o}rg and Chabrerie, Olivier and Cousins, Sara A. O. and Decocq, Guillaume and Dhondt, Rob and Diekmann, Martin and Eriksson, Olof and Heinken, Thilo and Hermy, Martin and J{\"o}gar, uelle and Saguez, Robert and Shevtsova, Anna and Stanton, Sharon and Zindel, Renate and Zobel, Martin and Verheyen, Kris}, title = {Significant effects of temperature on the reproductive output of the forest herb Anemone nemorosa L.}, issn = {0378-1127}, doi = {10.1016/j.foreco.2009.04.038}, year = {2010}, abstract = {Climate warming is already influencing plant migration in different parts of the world. Numerous models have been developed to forecast future plant distributions. Few studies, however, have investigated the potential effect of warming on the reproductive output of plants. Understorey forest herbs in particular, have received little attention in the debate on climate change impacts. This study focuses on the effect of temperature on sexual reproductive output (number of seeds, seed mass, germination percentage and seedling mass) of Anemone nemorosa L., a model species for slow colonizing herbaceous forest plants. We sampled seeds of A. nemorosa in populations along a 2400 km latitudinal gradient from northern France to northern Sweden during three growing seasons (2005,2006 and 2008). This study design allowed us to isolate the effects of accumulated temperature (Growing Degree Hours; GDH) from latitude and the local abiotic and biotic environment. Germination and seed sowing trials were performed in incubators, a greenhouse and under field conditions in a forest. Finally, we disentangled correlations between the different reproductive traits of A. nemorosa along the latitudinal gradient. We found a clear positive relationship between accumulated temperature and seed and seedling traits: reproductive output of A. nemorosa improved with increasing GDH along the latitudinal gradient. Seed mass and seedling mass, for instance, increased by 9.7\% and 10.4\%, respectively, for every 1000 degrees C h increase in GDH. We also derived strong correlations between several seed and seedling traits both under field conditions and in incubators. Our results indicate that seed mass, incubator-based germination percentage (Germ\%(Inc)) and the output of germinable seeds (product of number of seeds and Germ\%(Inc) divided by 100) from plants grown along a latitudinal gradient (i.e. at different temperature regimes) provide valuable proxies to parameterize key population processes in models. We conclude that (1) climate warming may have a pronounced positive impact on sexual reproduction of A. nemorosa and (2) climate models forecasting plant distributions would benefit from including the temperature sensitivity of key seed traits and population processes.}, language = {en} } @article{DeFrenneGraaeKolbetal.2011, author = {De Frenne, Pieter and Graae, Bente J. and Kolb, Annette and Shevtsova, Anna and Baeten, Lander and Brunet, J{\"o}rg and Chabrerie, Olivier and Cousins, Sara A. O. and Decocq, Guillaume and Dhondt, Rob and Diekmann, Martin and Gruwez, Robert and Heinken, Thilo and Hermy, Martin and Oster, Mathias and Saguez, Robert and Stanton, Sharon and Tack, Wesley and Vanhellemont, Margot and Verheyen, Kris}, title = {An intraspecific application of the leaf-height-seed ecology strategy scheme to forest herbs along a latitudinal gradient}, series = {Ecography : pattern and diversity in ecology ; research papers forum}, volume = {34}, journal = {Ecography : pattern and diversity in ecology ; research papers forum}, number = {1}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {0906-7590}, doi = {10.1111/j.1600-0587.2010.06399.x}, pages = {132 -- 140}, year = {2011}, abstract = {We measured LHS traits in 41 Anemone nemorosa and 44 Milium effusum populations along a 1900-2300 km latitudinal gradient from N France to N Sweden. We then applied multilevel models to identify the effects of regional (temperature, latitude) and local (soil fertility and acidity, overstorey canopy cover) environmental factors on LHS traits. Both species displayed a significant 4\% increase in plant height with every degree northward shift (almost a two-fold plant height difference between the southernmost and northernmost populations). Neither seed mass nor SLA showed a significant latitudinal cline. Temperature had a large effect on the three LHS traits of Anemone. Latitude, canopy cover and soil nutrients were related to the SLA and plant height of Milium. None of the investigated variables appeared to be related to the seed mass of Milium. The variation in LHS traits indicates that the ecological strategy determined by the position of each population in this three-factor triangle is not constant along the latitudinal gradient. The significant increase in plant height suggests greater competitive abilities for both species in the northernmost populations. We also found that the studied environmental factors affected the LHS traits of the two species on various scales: spring-flowering Anemone was affected more by temperature, whereas early-summer flowering Milium was affected more by local and other latitude-related factors. Finally, previously reported cross-species correlations between LHS traits and latitude were generally unsupported by our within-species approach.}, language = {en} } @article{DeFrenneGraaeBrunetetal.2012, author = {De Frenne, Pieter and Graae, Bente J. and Brunet, J{\"o}rg and Shevtsova, Anna and De Schrijver, An and Chabrerie, Olivier and Cousins, Sara A. O. and Decocq, Guillaume and Diekmann, Martin and Hermy, Martin and Heinken, Thilo and Kolb, Annette and Nilsson, Christer and Stanton, Sharon and Verheyen, Kris}, title = {The response of forest plant regeneration to temperature variation along a latitudinal gradient}, series = {Annals of botany}, volume = {109}, journal = {Annals of botany}, number = {5}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0305-7364}, doi = {10.1093/aob/mcs015}, pages = {1037 -- 1046}, year = {2012}, abstract = {The response of forest herb regeneration from seed to temperature variations across latitudes was experimentally assessed in order to forecast the likely response of understorey community dynamics to climate warming. Seeds of two characteristic forest plants (Anemone nemorosa and Milium effusum) were collected in natural populations along a latitudinal gradient from northern France to northern Sweden and exposed to three temperature regimes in growth chambers (first experiment). To test the importance of local adaptation, reciprocal transplants were also made of adult individuals that originated from the same populations in three common gardens located in southern, central and northern sites along the same gradient, and the resulting seeds were germinated (second experiment). Seedling establishment was quantified by measuring the timing and percentage of seedling emergence, and seedling biomass in both experiments. Spring warming increased emergence rates and seedling growth in the early-flowering forb A. nemorosa. Seedlings of the summer-flowering grass M. effusum originating from northern populations responded more strongly in terms of biomass growth to temperature than southern populations. The above-ground biomass of the seedlings of both species decreased with increasing latitude of origin, irrespective of whether seeds were collected from natural populations or from the common gardens. The emergence percentage decreased with increasing home-away distance in seeds from the transplant experiment, suggesting that the maternal plants were locally adapted. Decreasing seedling emergence and growth were found from the centre to the northern edge of the distribution range for both species. Stronger responses to temperature variation in seedling growth of the grass M. effusum in the north may offer a way to cope with environmental change. The results further suggest that climate warming might differentially affect seedling establishment of understorey plants across their distribution range and thus alter future understorey plant dynamics.}, language = {en} } @article{DeFrenneBrunetShevtsovaetal.2011, author = {De Frenne, Pieter and Brunet, Jorg and Shevtsova, Anna and Kolb, Annette and Graae, Bente J. and Chabrerie, Olivier and Cousins, Sara Ao and Decocq, Guillaume and De Schrijver, An and Diekmann, Martin and Gruwez, Robert and Heinken, Thilo and Hermy, Martin and Nilsson, Christer and Stanton, Sharon and Tack, Wesley and Willaert, Justin and Verheyen, Kris}, title = {Temperature effects on forest herbs assessed by warming and transplant experiments along a latitudinal gradient}, series = {Global change biology}, volume = {17}, journal = {Global change biology}, number = {10}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {1354-1013}, doi = {10.1111/j.1365-2486.2011.02449.x}, pages = {3240 -- 3253}, year = {2011}, abstract = {Slow-colonizing forest understorey plants are probably not able to rapidly adjust their distribution range following large-scale climate change. Therefore, the acclimation potential to climate change within their actual occupied habitats will likely be key for their short-and long-term persistence. We combined transplant experiments along a latitudinal gradient with open-top chambers to assess the effects of temperature on phenology, growth and reproductive performance of multiple populations of slow-colonizing understorey plants, using the spring flowering geophytic forb Anemone nemorosa and the early summer flowering grass Milium effusum as study species. In both species, emergence time and start of flowering clearly advanced with increasing temperatures. Vegetative growth (plant height, aboveground biomass) and reproductive success (seed mass, seed germination and germinable seed output) of A. nemorosa benefited from higher temperatures. Climate warming may thus increase future competitive ability and colonization rates of this species. Apart from the effects on phenology, growth and reproductive performance of M. effusum generally decreased when transplanted southwards (e. g., plant size and number of individuals decreased towards the south) and was probably more limited by light availability in the south. Specific leaf area of both species increased when transplanted southwards, but decreased with open-top chamber installation in A. nemorosa. In general, individuals of both species transplanted at the home site performed best, suggesting local adaptation. We conclude that contrasting understorey plants may display divergent plasticity in response to changing temperatures which may alter future understorey community dynamics.}, language = {en} } @article{DeFrenneBlondeelBrunetetal.2018, author = {De Frenne, Pieter and Blondeel, H. and Brunet, J. and Caron, M. M. and Chabrerie, O. and Cougnon, M. and Cousins, S. A. O. and Decocq, G. and Diekmann, M. and Graae, B. J. and Hanley, M. E. and Heinken, Thilo and Hermy, M. and Kolb, A. and Lenoir, J. and Liira, J. and Orczewska, A. and Shevtsova, A. and Vanneste, T. and Verheyen, K.}, title = {Atmospheric nitrogen deposition on petals enhances seed quality of the forest herb Anemone nemorosa}, series = {Plant biology}, volume = {20}, journal = {Plant biology}, number = {3}, publisher = {Wiley}, address = {Hoboken}, issn = {1435-8603}, doi = {10.1111/plb.12688}, pages = {619 -- 626}, year = {2018}, abstract = {Elevated atmospheric input of nitrogen (N) is currently affecting plant biodiversity and ecosystem functioning. The growth and survival of numerous plant species is known to respond strongly to N fertilisation. Yet, few studies have assessed the effects of N deposition on seed quality and reproductive performance, which is an important life-history stage of plants. Here we address this knowledge gap by assessing the effects of atmospheric N deposition on seed quality of the ancient forest herb Anemone nemorosa using two complementary approaches. By taking advantage of the wide spatiotemporal variation in N deposition rates in pan-European temperate and boreal forests over 2years, we detected positive effects of N deposition on the N concentration (percentage N per unit seed mass, increased from 2.8\% to 4.1\%) and N content (total N mass per seed more than doubled) of A.nemorosa seeds. In a complementary experiment, we applied ammonium nitrate to aboveground plant tissues and the soil surface to determine whether dissolved N sources in precipitation could be incorporated into seeds. Although the addition of N to leaves and the soil surface had no effect, a concentrated N solution applied to petals during anthesis resulted in increased seed mass, seed N concentration and N content. Our results demonstrate that N deposition on the petals enhances bioaccumulation of N in the seeds of A.nemorosa. Enhanced atmospheric inputs of N can thus not only affect growth and population dynamics via root or canopy uptake, but can also influence seed quality and reproduction via intake through the inflorescences.}, language = {en} } @article{DeFrenneKolbGraaeetal.2011, author = {De Frenne, P. and Kolb, Annette and Graae, Benete Jessen and Decocq, Guillaume and Baltora, S. and De Schrijver, A. and Brunet, J. and Chabrerie, Olivier and Cousins, Sara A. O. and Dhondt, Rob and Diekmann, Martin and Gruwez, R. and Heinken, Thilo and Hermy, Martin and Liira, J. and Saguez, R. and Shevtsova, Anna and Baskin, Carol C. and Verheyen, Kris}, title = {A latitudinal gradient in seed nutrients of the forest herb Anemone nemorosa}, series = {Plant biology}, volume = {13}, journal = {Plant biology}, number = {3}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {1435-8603}, doi = {10.1111/j.1438-8677.2010.00404.x}, pages = {493 -- 501}, year = {2011}, abstract = {The nutrient concentration in seeds determines many aspects of potential success of the sexual reproductive phase of plants, including the seed predation probability, efficiency of seed dispersal and seedling performance. Despite considerable research interest in latitudinal gradients of foliar nutrients, a similar gradient for seeds remains unexplored. We investigated a potential latitudinal gradient in seed nutrient concentrations within the widespread European understorey forest herb Anemone nemorosa L. We sampled seeds of A. nemorosa in 15 populations along a 1900-km long latitudinal gradient at three to seven seed collection dates post-anthesis and investigated the relative effects of growing degree-hours > 5 degrees C, soil characteristics and latitude on seed nutrient concentrations. Seed nitrogen, nitrogen:phosphorus ratio and calcium concentration decreased towards northern latitudes, while carbon:nitrogen ratios increased. When taking differences in growing degree-hours and measured soil characteristics into account and only considering the most mature seeds, the latitudinal decline remained particularly significant for seed nitrogen concentration. We argue that the decline in seed nitrogen concentration can be attributed to northward decreasing seed provisioning due to lower soil nitrogen availability or greater investment in clonal reproduction. This pattern may have large implications for the reproductive performance of this forest herb as the degree of seed provisioning ultimately co-determines seedling survival and reproductive success.}, language = {en} }