TY - JOUR A1 - Plue, Jan A1 - De Frenne, Pieter A1 - Acharya, Kamal A1 - Brunet, Jörg A1 - Chabrerie, Olivier A1 - Decocq, Guillaume A1 - Diekmann, Martin A1 - Graae, Bente J. A1 - Heinken, Thilo A1 - Hermy, Martin A1 - Kolb, Annette A1 - Lemke, Isgard A1 - Liira, Jaan A1 - Naaf, Tobias A1 - Verheyen, Kris A1 - Wulf, Monika A1 - Cousins, Sara A. O. T1 - Where does the community start, and where does it end? BT - including the seed bank to reassess forest herb layer responses to the environment JF - Journal of vegetation science N2 - 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. KW - Above-ground KW - Below-ground KW - Canopy KW - Disturbance KW - Diversity KW - Light availability KW - NWEurope KW - Plant community KW - Species co-existence KW - Storage effect Y1 - 2017 U6 - https://doi.org/10.1111/jvs.12493 SN - 1100-9233 SN - 1654-1103 VL - 28 IS - 2 SP - 424 EP - 435 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Vanneste, Thomas A1 - Valdes, Alicia A1 - Verheyen, Kris A1 - Perring, Michael P. A1 - Bernhardt-Roemermann, Markus A1 - Andrieu, Emilie A1 - Brunet, Jorg A1 - Cousins, Sara A. O. A1 - Deconchat, Marc A1 - De Smedt, Pallieter A1 - Diekmann, Martin A1 - Ehrmann, Steffen A1 - Heinken, Thilo A1 - Hermy, Martin A1 - Kolb, Annette A1 - Lenoir, Jonathan A1 - Liira, Jaan A1 - Naaf, Tobias A1 - Paal, Taavi A1 - Wulf, Monika A1 - Decocq, Guillaume A1 - De Frenne, Pieter T1 - Functional trait variation of forest understorey plant communities across Europe JF - Basic and applied ecology : Journal of the Gesellschaft für Ökologie N2 - 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. KW - Agricultural landscapes KW - Biogeography KW - Community ecology KW - Forest understorey KW - Functional trait diversity KW - Fragmentation KW - Global environmental change KW - Landscape connectivity KW - Macroclimatic gradient KW - Multi-scale analysis Y1 - 2018 U6 - https://doi.org/10.1016/j.baae.2018.09.004 SN - 1439-1791 SN - 1618-0089 VL - 34 SP - 1 EP - 14 PB - Elsevier GmbH CY - München ER - TY - JOUR A1 - de Frenne, Pieter A1 - Graae, Bente Jessen A1 - Kolb, Annette A1 - Brunet, Jörg A1 - Chabrerie, Olivier A1 - Cousins, Sara A. O. A1 - Decocq, Guillaume A1 - Dhondt, Rob A1 - Diekmann, Martin A1 - Eriksson, Olof A1 - Heinken, Thilo A1 - Hermy, Martin A1 - Jögar, uelle A1 - Saguez, Robert A1 - Shevtsova, Anna A1 - Stanton, Sharon A1 - Zindel, Renate A1 - Zobel, Martin A1 - Verheyen, Kris T1 - Significant effects of temperature on the reproductive output of the forest herb Anemone nemorosa L. N2 - 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. Y1 - 2010 UR - http://www.sciencedirect.com/science/journal/03781127 U6 - https://doi.org/10.1016/j.foreco.2009.04.038 SN - 0378-1127 ER - TY - JOUR A1 - Plue, Jan A1 - De Frenne, Pieter A1 - Acharya, Kamal P. A1 - Brunet, Jorg A1 - Chabrerie, Olivier A1 - Decocq, Guillaume A1 - Diekmann, Martin A1 - Graae, Bente J. A1 - Heinken, Thilo A1 - Hermy, Martin A1 - Kolb, Annette A1 - Lemke, Isgard A1 - Liira, Jaan A1 - Naaf, Tobias A1 - Shevtsova, Anna A1 - Verheyen, Kris A1 - Wulf, Monika A1 - Cousins, Sara A. O. T1 - Climatic control of forest herb seed banks along a latitudinal gradient JF - Global ecology and biogeography : a journal of macroecology N2 - 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. KW - Climate change KW - interspecific variation KW - plant-climate interaction KW - seed longevity KW - seed production KW - temperate deciduous forest KW - temperature Y1 - 2013 U6 - https://doi.org/10.1111/geb.12068 SN - 1466-822X SN - 1466-8238 VL - 22 IS - 10 SP - 1106 EP - 1117 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Wasof, Safaa A1 - Lenoir, Jonathan A1 - Gallet-Moron, Emilie A1 - Jamoneau, Aurelien A1 - Brunet, Jörg A1 - Cousins, Sara A. O. A1 - De Frenne, Pieter A1 - Diekmann, Martin A1 - Hermy, Martin A1 - Kolb, Annette A1 - Liira, Jaan A1 - Verheyen, Kris A1 - Wulf, Monika A1 - Decocq, Guillaume T1 - Ecological niche shifts of understorey plants along a latitudinal gradient of temperate forests in north-western Europe JF - Global ecology and biogeography : a journal of macroecology N2 - Aim In response to environmental changes and to avoid extinction, species may either track suitable environmental conditions or adapt to the modified environment. However, whether and how species adapt to environmental changes remains unclear. By focusing on the realized niche (i.e. the actual space that a species inhabits and the resources it can access as a result of limiting biotic factors present in its habitat), we here examine shifts in the realized-niche width (i.e. ecological amplitude) and position (i.e. ecological optimum) of 26 common and widespread forest understorey plants across their distributional ranges. Location Temperate forests along a ca. 1800-km-long latitudinal gradient from northern France to central Sweden and Estonia. Methods We derived species' realized-niche width from a -diversity metric, which increases if the focal species co-occurs with more species. Based on the concept that species' scores in a detrended correspondence analysis (DCA) represent the locations of their realized-niche positions, we developed a novel approach to run species-specific DCAs allowing the focal species to shift its realized-niche position along the studied latitudinal gradient while the realized-niche positions of other species were held constant. Results None of the 26 species maintained both their realized-niche width and position along the latitudinal gradient. Few species (9 of 26: 35%) shifted their realized-niche width, but all shifted their realized-niche position. With increasing latitude, most species (22 of 26: 85%) shifted their realized-niche position for soil nutrients and pH towards nutrient-poorer and more acidic soils. Main conclusions Forest understorey plants shifted their realized niche along the latitudinal gradient, suggesting local adaptation and/or plasticity. This macroecological pattern casts doubt on the idea that the realized niche is stable in space and time, which is a key assumption of species distribution models used to predict the future of biodiversity, hence raising concern about predicted extinction rates. KW - Beta diversity KW - climate change KW - detrended correspondence analyses KW - Ellenberg indicator values KW - forest understorey plant species KW - niche optimum KW - niche width KW - plant community KW - realized niche Y1 - 2013 U6 - https://doi.org/10.1111/geb.12073 SN - 1466-822X VL - 22 IS - 10 SP - 1130 EP - 1140 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - de Frenne, Pieter A1 - Kolb, Annette A1 - Verheyen, Kris A1 - Brunet, Johanne A1 - Chabrerie, Olivier A1 - Decocq, Guillaume A1 - Diekmann, Martin A1 - Eriksson, Ove A1 - Heinken, Thilo A1 - Hermy, Martin A1 - Jõgar, Ülle A1 - Stanton, Sara A1 - Quataert, Paul A1 - Zindel, Renate A1 - Zobel, Martin A1 - Graae, Bente Jessen T1 - Unravelling the effects of temperature, latitude and local environment on the reproduction of forest herbs N2 - 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. Y1 - 2009 UR - http://www3.interscience.wiley.com/journal/118545893/home U6 - https://doi.org/10.1111/j.1466-8238.2009.00487.x SN - 1466-822X ER - TY - JOUR A1 - Graae, Bente Jessen A1 - Verheyen, Kris A1 - Kolb, Annette A1 - van der Veken, Sebastian A1 - Heinken, Thilo A1 - Chabrerie, Olivier A1 - Diekmann, Martin A1 - Valtinat, Karin A1 - Zindel, Renate A1 - Karlsson, Elisabeth A1 - Ström, Lotta A1 - Decocq, Guillaume A1 - Hermy, Martin A1 - Baskin, Carol C. T1 - Germination requirements and seed mass of slow- and fast-colonizing temperate forest herbs along a latitudinal gradient N2 - 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. Y1 - 2009 UR - http://www.bioone.org/loi/ecos U6 - https://doi.org/10.2980/16-2-3234 SN - 1195-6860 ER - TY - JOUR A1 - Caron, Maria Mercedes A1 - De Frenne, Pieter A1 - Brunet, Jörg A1 - Chabrerie, Olivier A1 - Cousins, Sara A. O. A1 - Decocq, Guillaume A1 - Diekmann, Martin A1 - Graae, Bente Jessen A1 - Heinken, Thilo A1 - Kolb, Annette A1 - Lenoir, Jonathan A1 - Naaf, Tobias A1 - Plue, Jan A1 - Selvi, Federico A1 - Wulf, Monika A1 - Verheyen, Kris T1 - Divergent regeneration responses of two closely related tree species to direct abiotic and indirect biotic effects of climate change JF - Forest ecology and management N2 - Changing temperature and precipitation can strongly influence plant reproduction. However, also biotic interactions might indirectly affect the reproduction and recruitment success of plants in the context of climate change. Information about the interactive effects of changes in abiotic and biotic factors is essential, but still largely lacking, to better understand the potential effects of a changing climate on plant populations. Here we analyze the regeneration from seeds of Acer platanoides and Acer pseudoplatanus, two currently secondary forest tree species from seven regions along a 2200 km-wide latitudinal gradient in Europe. We assessed the germination, seedling survival and growth during two years in a common garden experiment where temperature, precipitation and competition with the understory vegetation were manipulated. A. platanoides was more sensitive to changes in biotic conditions while A. pseudoplatanus was affected by both abiotic and biotic changes. In general, competition reduced (in A. platanoides) and warming enhanced (in A. pseudoplatanus) germination and survival, respectively. Reduced competition strongly increased the growth of A. platanoides seedlings. Seedling responses were independent of the conditions experienced by the mother tree during seed production and maturation. Our results indicate that, due to the negative effects of competition on the regeneration of A. platanoides, it is likely that under stronger competition (projected under future climatic conditions) this species will be negatively affected in terms of germination, survival and seedling biomass. Climate-change experiments including both abiotic and biotic factors constitute a key step forward to better understand the response of tree species' regeneration to climate change. (C) 2015 Elsevier B.V. All rights reserved. KW - Acer KW - Regeneration KW - Latitudinal gradient KW - Temperature KW - Precipitation KW - Competition Y1 - 2015 U6 - https://doi.org/10.1016/j.foreco.2015.01.003 SN - 0378-1127 SN - 1872-7042 VL - 342 SP - 21 EP - 29 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - De Frenne, Pieter A1 - Graae, Bente J. A1 - Brunet, Jörg A1 - Shevtsova, Anna A1 - De Schrijver, An A1 - Chabrerie, Olivier A1 - Cousins, Sara A. O. A1 - Decocq, Guillaume A1 - Diekmann, Martin A1 - Hermy, Martin A1 - Heinken, Thilo A1 - Kolb, Annette A1 - Nilsson, Christer A1 - Stanton, Sharon A1 - Verheyen, Kris T1 - The response of forest plant regeneration to temperature variation along a latitudinal gradient JF - Annals of botany N2 - 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. KW - Anemone nemorosa KW - climate change KW - common garden KW - growth chambers KW - latitudinal gradient KW - local adaptation KW - Milium effusum KW - plant regeneration KW - range edges KW - recruitment KW - seedling establishment KW - temperature Y1 - 2012 U6 - https://doi.org/10.1093/aob/mcs015 SN - 0305-7364 VL - 109 IS - 5 SP - 1037 EP - 1046 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - De Frenne, P. A1 - Kolb, Annette A1 - Graae, Benete Jessen A1 - Decocq, Guillaume A1 - Baltora, S. A1 - De Schrijver, A. A1 - Brunet, J. A1 - Chabrerie, Olivier A1 - Cousins, Sara A. O. A1 - Dhondt, Rob A1 - Diekmann, Martin A1 - Gruwez, R. A1 - Heinken, Thilo A1 - Hermy, Martin A1 - Liira, J. A1 - Saguez, R. A1 - Shevtsova, Anna A1 - Baskin, Carol C. A1 - Verheyen, Kris T1 - A latitudinal gradient in seed nutrients of the forest herb Anemone nemorosa JF - Plant biology N2 - 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. KW - Collection date KW - latitude KW - nutrient stoichiometry KW - seed nitrogen KW - seed predation KW - seed provisioning KW - sexual reproduction KW - wood anemone Y1 - 2011 U6 - https://doi.org/10.1111/j.1438-8677.2010.00404.x SN - 1435-8603 VL - 13 IS - 3 SP - 493 EP - 501 PB - Wiley-Blackwell CY - Malden ER -