@article{OlasApeltWatanabeetal.2021, author = {Olas, Justyna Jadwiga and Apelt, Federico and Watanabe, Mutsumi and H{\"o}fgen, Rainer and Wahl, Vanessa}, title = {Developmental stage-specific metabolite signatures in Arabidopsis thaliana under optimal and mild nitrogen limitation}, series = {Plant science : an international journal of experimental plant biology}, volume = {303}, journal = {Plant science : an international journal of experimental plant biology}, publisher = {Elsevier Science}, address = {Amsterdam [u.a.]}, issn = {0168-9452}, doi = {10.1016/j.plantsci.2020.110746}, pages = {14}, year = {2021}, abstract = {Metabolites influence flowering time, and thus are among the major determinants of yield. Despite the reported role of trehalose 6-phosphate and nitrate signaling on the transition from the vegetative to the reproductive phase, little is known about other metabolites contributing and responding to developmental phase changes. To increase our understanding which metabolic traits change throughout development in Arabidopsis thaliana and to identify metabolic markers for the vegetative and reproductive phases, especially among individual amino acids (AA), we profiled metabolites of plants grown in optimal (ON) and limited nitrogen (N) (LN) conditions, the latter providing a mild but consistent limitation of N. We found that although LN plants adapt their growth to a decreased level of N, their metabolite profiles are strongly distinct from ON plant profiles, with N as the driving factor for the observed differences. We demonstrate that the vegetative and the reproductive phase are not only marked by growth parameters such as biomass and rosette area, but also by specific metabolite signatures including specific single AA. In summary, we identified N-dependent and -independent indicators manifesting developmental stages, indicating that the plant's metabolic status also reports on the developmental phases.}, language = {en} } @article{RevereyGanzertLischeidetal.2018, author = {Reverey, Florian and Ganzert, Lars and Lischeid, Gunnar and Ulrich, Andreas and Premke, Katrin and Grossart, Hans-Peter}, title = {Dry-wet cycles of kettle hole sediments leave a microbial and biogeochemical legacy}, series = {The science of the total environment : an international journal for scientific research into the environment and its relationship with man}, volume = {627}, journal = {The science of the total environment : an international journal for scientific research into the environment and its relationship with man}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0048-9697}, doi = {10.1016/j.scitotenv.2018.01.220}, pages = {985 -- 996}, year = {2018}, abstract = {Understanding interrelations between an environment's hydrological past and its current biogeochemistry is necessary for the assessment of biogeochemical and microbial responses to changing hydrological conditions. The question how previous dry-wet events determine the contemporary microbial and biogeochemical state is addressed in this study. Therefore, sediments exposed to the atmosphere of areas with a different hydrological past within one kettle hole, i.e. (1) the predominantly inundated pond center, (2) the pond margin frequently desiccated for longer periods and (3) an intermediate zone, were incubated with the same rewetting treatment. Physicochemical and textural characteristics were related to structural microbial parameters regarding carbon and nitrogen turnover, i.e. abundance of bacteria and fungi, denitrifiers (targeted by the nirK und nirS functional genes) and nitrate ammonifiers (targeted by the nrfA functional gene). Our study reveals that, in combination with varying sediment texture, the hydrological history creates distinct microbial habitats with defined boundary conditions within the kettle hole, mainly driven by redox conditions, pH and organic matter (OM) composition. OM mineralization, as indicated by CO2-outgassing, was most efficient in exposed sediments with a less stable hydrological past. The potential for nitrogen retention via nitrate ammonification was highest in the hydrologically rather stable pond center, counteracting nitrogen loss due to denitrification. Therefore, the degree of hydrological stability is an important factor leaving a microbial and biogeochemical legacy, which determines carbon and nitrogen losses from small lentic freshwater systems in the long term run.}, language = {en} } @misc{RevereyGrossartPremkeetal.2016, author = {Reverey, Florian and Großart, Hans-Peter and Premke, Katrin and Lischeid, Gunnar}, title = {Carbon and nutrient cycling in kettle hole sediments depending on hydrological dynamics: a review}, series = {Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica}, volume = {775}, journal = {Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica}, publisher = {Springer}, address = {Dordrecht}, issn = {0018-8158}, doi = {10.1007/s10750-016-2715-9}, pages = {1 -- 20}, year = {2016}, abstract = {Kettle holes as a specific group of isolated, small lentic freshwater systems (LFS) often are (i) hot spots of biogeochemical cycling and (ii) exposed to frequent sediment desiccation and rewetting. Their ecological functioning is greatly determined by immanent carbon and nutrient transformations. The objective of this review is to elucidate effects of a changing hydrological regime (i.e., dry-wet cycles) on carbon and nutrient cycling in kettle hole sediments. Generally, dry-wet cycles have the potential to increase C and N losses as well as P availability. However, their duration and frequency are important controlling factors regarding direction and intensity of biogeochemical and microbiological responses. To evaluate drought impacts on sediment carbon and nutrient cycling in detail requires the context of the LFS hydrological history. For example, frequent drought events induce physiological adaptation of exposed microbial communities and thus flatten metabolic responses, whereas rare events provoke unbalanced, strong microbial responses. Different potential of microbial resilience to drought stress can irretrievably change microbial communities and functional guilds, gearing cascades of functional responses. Hence, dry-wet events can shift the biogeochemical cycling of organic matter and nutrients to a new equilibrium, thus affecting the dynamic balance between carbon burial and mineralization in kettle holes.}, language = {en} } @article{KlausKleinebeckerHoelzeletal.2011, author = {Klaus, Valentin H. and Kleinebecker, Till and Hoelzel, Norbert and Bluethgen, Nico and Boch, Steffen and M{\"u}ller, J{\"o}rg and Socher, Stephanie A. and Prati, Daniel and Fischer, Markus}, title = {Nutrient concentrations and fibre contents of plant community biomass reflect species richness patterns along a broad range of land-use intensities among agricultural grasslands}, series = {Perspectives in plant ecology, evolution and systematics}, volume = {13}, journal = {Perspectives in plant ecology, evolution and systematics}, number = {4}, publisher = {Elsevier}, address = {Jena}, issn = {1433-8319}, doi = {10.1016/j.ppees.2011.07.001}, pages = {287 -- 295}, year = {2011}, abstract = {Understanding changes in biodiversity in agricultural landscapes in relation to land-use type and intensity is a major issue in current ecological research. In this context nutrient enrichment has been identified as a key mechanism inducing species loss in Central European grassland ecosystems. At the same time, insights into the linkage between agricultural land use and plant nutrient status are largely missing. So far, studies on the relationship between chemical composition of plant community biomass and biodiversity have mainly been restricted to wetlands and all these studies neglected the effects of land use. Therefore, we analyzed aboveground biomass of 145 grassland plots covering a gradient of land-use intensities in three regions across Germany. In particular, we explored relationships between vascular plant species richness and nutrient concentrations as well as fibre contents (neutral and acid detergent fibre and lignin) in the aboveground community biomass. We found the concentrations of several nutrients in the biomass to be closely linked to plant species richness and land use. Whereas phosphorus concentrations increased with land-use intensity and decreased with plant species richness, nitrogen and potassium concentrations showed less clear patterns. Fibre fractions were negatively related to nutrient concentrations in biomass, but hardly to land-use measures and species richness. Only high lignin contents were positively associated with species richness of grasslands. The N:P ratio was strongly positively related to species richness and even more so to the number of endangered plant species, indicating a higher persistence of endangered species under P (co-)limited conditions. Therefore, we stress the importance of low P supply for species-rich grasslands and suggest the N:P ratio in community biomass to be a useful proxy of the conservation value of agriculturally used grasslands.}, language = {en} } @article{BluethgenDormannPratietal.2012, author = {Bl{\"u}thgen, Nico and Dormann, Carsten F. and Prati, Daniel and Klaus, Valentin H. and Kleinebecker, Till and Hoelzel, Norbert and Alt, Fabian and Boch, Steffen and Gockel, Sonja and Hemp, Andreas and M{\"u}ller, J{\"o}rg and Nieschulze, Jens and Renner, Swen C. and Sch{\"o}ning, Ingo and Schumacher, Uta and Socher, Stephanie A. and Wells, Konstans and Birkhofer, Klaus and Buscot, Francois and Oelmann, Yvonne and Rothenw{\"o}hrer, Christoph and Scherber, Christoph and Tscharntke, Teja and Weiner, Christiane N. and Fischer, Markus and Kalko, Elisabeth K. V. and Linsenmair, Karl Eduard and Schulze, Ernst-Detlef and Weisser, Wolfgang W.}, title = {A quantitative index of land-use intensity in grasslands integrating mowing, grazing and fertilization}, series = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, volume = {13}, journal = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, number = {3}, publisher = {Elsevier}, address = {Jena}, issn = {1439-1791}, doi = {10.1016/j.baae.2012.04.001}, pages = {207 -- 220}, year = {2012}, abstract = {Land use is increasingly recognized as a major driver of biodiversity and ecosystem functioning in many current research projects. In grasslands, land use is often classified by categorical descriptors such as pastures versus meadows or fertilized versus unfertilized sites. However, to account for the quantitative variation of multiple land-use types in heterogeneous landscapes, a quantitative, continuous index of land-use intensity (LUI) is desirable. Here we define such a compound, additive LUI index for managed grasslands including meadows and pastures. The LUI index summarizes the standardized intensity of three components of land use, namely fertilization, mowing, and livestock grazing at each site. We examined the performance of the LUI index to predict selected response variables on up to 150 grassland sites in the Biodiversity Exploratories in three regions in Germany(Alb, Hainich, Schorlheide). We tested the average Ellenberg nitrogen indicator values of the plant community, nitrogen and phosphorus concentration in the aboveground plant biomass, plant-available phosphorus concentration in the top soil, and soil C/N ratio, and the first principle component of these five response variables. The LUI index significantly predicted the principal component of all five response variables, as well as some of the individual responses. Moreover, vascular plant diversity decreased significantly with LUI in two regions (Alb and Hainich). Inter-annual changes in management practice were pronounced from 2006 to 2008, particularly due to variation in grazing intensity. This rendered the selection of the appropriate reference year(s) an important decision for analyses of land-use effects, whereas details in the standardization of the index were of minor importance. We also tested several alternative calculations of a LUI index, but all are strongly linearly correlated to the proposed index. The proposed LUI index reduces the complexity of agricultural practices to a single dimension and may serve as a baseline to test how different groups of organisms and processes respond to land use. In combination with more detailed analyses, this index may help to unravel whether and how land-use intensities, associated disturbance levels or other local or regional influences drive ecological processes.}, language = {en} } @article{KlausKleinebeckerBochetal.2012, author = {Klaus, Valentin H. and Kleinebecker, Till and Boch, Steffen and M{\"u}ller, J{\"o}rg and Socher, Stephanie A. and Prati, Daniel and Fischer, Markus and Hoelzel, Norbert}, title = {NIRS meets Ellenberg's indicator values prediction of moisture and nitrogen values of agricultural grassland vegetation by means of near-infrared spectral characteristics}, series = {Ecological indicators : integrating monitoring, assessment and management}, volume = {14}, journal = {Ecological indicators : integrating monitoring, assessment and management}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1470-160X}, doi = {10.1016/j.ecolind.2011.07.016}, pages = {82 -- 86}, year = {2012}, abstract = {Ellenberg indicator values are widely used ecological tools to elucidate relationships between vegetation and environment in ecological research and environmental planning. However, they are mainly deduced from expert knowledge on plant species and are thus subject of ongoing discussion. We researched if Ellenberg indicator values can be directly extracted from the vegetation biomass itself. Mean Ellenberg "moisture" (mF) and "nitrogen" (mN) values of 141 grassland plots were related to nutrient concentrations, fibre fractions and spectral information of the aboveground biomass. We developed calibration models for the prediction of mF and mN using spectral characteristics of biomass samples with near-infrared reflectance spectroscopy (NIRS). Prediction goodness was evaluated with internal cross-validations and with an external validation data set. NIRS could accurately predict Ellenberg mN, and with less accuracy Ellenberg mF. Predictions were not more precise for cover-weighted Ellenberg values compared with un-weighted values. Both Ellenberg mN and mF showed significant and strong correlations with some of the nutrient and fibre concentrations in the biomass. Against expectations, Ellenberg mN was more closely related to phosphorus than to nitrogen concentrations, suggesting that this value rather indicates productivity than solely nitrogen. To our knowledge we showed for the first time that mean Ellenberg indicator values could be directly predicted from the aboveground biomass, which underlines the usefulness of the NIRS technology for ecological studies, especially in grasslands ecosystems.}, language = {en} } @article{HancockWaeschkeSchumacheretal.2013, author = {Hancock, Christine and W{\"a}schke, Nicole and Schumacher, Uta and Linsenmair, Karl Eduard and Meiners, Torsten and Obermaier, Elisabeth}, title = {Fertilizer application decreases insect abundance on Plantago lanceolata - a large-scale experiment in three geographic regions}, series = {Arthropod-plant interactions : an international journal devoted to studies on interactions of insects, mites, and other arthropods with plants}, volume = {7}, journal = {Arthropod-plant interactions : an international journal devoted to studies on interactions of insects, mites, and other arthropods with plants}, number = {2}, publisher = {Springer}, address = {Dordrecht}, issn = {1872-8855}, doi = {10.1007/s11829-012-9237-9}, pages = {147 -- 158}, year = {2013}, abstract = {Humans have substantially altered the nitrogen cycle of ecosystems through the application of agricultural fertilizer. Fertilization may not only affect plant species diversity, but also insect dynamics by altering plant nitrogen supplies. We investigated the effect of experimental fertilization on the vegetation, with the ribwort plantain as the focal plant, and on higher trophic levels on differently managed grasslands throughout Germany. Over a period of 2 years, we examined two specialist herbivores and their parasitoid on Plantago lanceolata L., and the composition and structure of the surrounding vegetation. Over 70 sites in three geographic regions, within the large-scale project "German Biodiversity Exploratories", were included in the study. The model system consisted of the host plant P. lanceolata L., the monophagous weevils Mecinus labilis Herbst and M. pascuorum Gyllenhal, and their parasitoid Mesopolobus incultus Walker. Fertilization decreased plant species richness and host plant abundance, whereas it enhanced the total vegetation growth. The increased size and heigher leaf nitrogen content did not improve herbivore performance. On the contrary, the abundance of the two herbivores was decreased by fertilization. The parasitoid depended on the abundance of one of its hosts, M. pascuorum (positively density-dependent). Reduced herbivore abundance due to fertilization might be explained by a lower abundance of the host plant, a lower stalk number, and by changed patterns of host localization within higher vegetation. Fertilization negatively affected the third trophic level by cascading up via host abundance. The relationships between fertilization, surrounding vegetation and the tritrophic system were measured throughout the three regions and over the 2-year period. Our findings present consequences of intensification for a plant-herbivore-parasitoid system, and may have significant implications for the conservation of multitrophic systems in managed grasslands.}, language = {en} } @article{KlausKleinebeckerPratietal.2013, author = {Klaus, Valentin H. and Kleinebecker, Till and Prati, Daniel and Gossner, Martin M. and Alt, Fabian and Boch, Steffen and Gockel, Sonja and Hemp, Andreas and Lange, Markus and M{\"u}ller, J{\"o}rg and Oelmann, Yvonne and Pasalic, Esther and Renner, Swen C. and Socher, Stephanie A. and T{\"u}rke, Manfred and Weisser, Wolfgang W. and Fischer, Markus and H{\"o}lzel, Norbert}, title = {Does organic grassland farming benefit plant and arthropod diversity at the expense of yield and soil fertility?}, series = {Agriculture, ecosystems \& environment : an international journal for scientific research on the relationship of agriculture and food production to the biosphere}, volume = {177}, journal = {Agriculture, ecosystems \& environment : an international journal for scientific research on the relationship of agriculture and food production to the biosphere}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0167-8809}, doi = {10.1016/j.agee.2013.05.019}, pages = {1 -- 9}, year = {2013}, abstract = {Organic management is one of the most popular strategies to reduce negative environmental impacts of intensive agriculture. However, little is known about benefits for biodiversity and potential worsening of yield under organic grasslands management across different grassland types, i.e. meadow, pasture and mown pasture. Therefore, we studied the diversity of vascular plants and foliage-living arthropods (Coleoptera, Araneae, Heteroptera, Auchenorrhyncha), yield, fodder quality, soil phosphorus concentrations and land-use intensity of organic and conventional grasslands across three study regions in Germany. Furthermore, all variables were related to the time since conversion to organic management in order to assess temporal developments reaching up to 18 years. Arthropod diversity was significantly higher under organic than conventional management, although this was not the case for Araneae, Heteroptera and Auchenorrhyncha when analyzed separately. On the contrary, arthropod abundance, vascular plant diversity and also yield and fodder quality did not considerably differ between organic and conventional grasslands. Analyses did not reveal differences in the effect of organic management among grassland types. None of the recorded abiotic and biotic parameters showed a significant trend with time since transition to organic management, except soil organic phosphorus concentrations which decreased with time. This implies that permanent grasslands respond slower and probably weaker to organic management than crop fields do. However, as land-use intensity and inorganic soil phosphorus concentrations were significantly lower in organic grasslands, overcoming seed and dispersal limitation by re-introducing plant species might be needed to exploit the full ecological potential of organic grassland management. We conclude that although organic management did not automatically increase the diversity of all studied taxa, it is a reasonable and useful way to support agro-biodiversity.}, language = {en} } @article{LeuschnerWulfBaeuchleretal.2013, author = {Leuschner, Christoph and Wulf, Monika and B{\"a}uchler, Patricia and Hertel, Dietrich}, title = {Soil C and nutrient stores under Scots pine afforestations compared to ancient beech forests in the German Pleistocene - the role of tree species and forest history}, series = {Forest ecology and management}, volume = {310}, journal = {Forest ecology and management}, number = {6}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0378-1127}, doi = {10.1016/j.foreco.2013.08.043}, pages = {405 -- 415}, year = {2013}, abstract = {In the diluvial lowlands of northern Germany, the Netherlands and northern Poland, an estimated similar to 5 Mio ha of Scots pine plantations (Pinus sylvestris) has been established on sandy soil in the last 250 years replacing the former temperate broad-leaved forests after extended periods of cultivation in the Middle Ages. We examined the effect of variable stand continuity of pine plantations (recent vs. ancient: 51-128 vs. >230 years) on the soil organic carbon (SOC) store and soil nutrient capital in comparison to ancient beech forests (>230 years of continuity) which represent the potential natural forest vegetation. Recent and ancient pine stands had c. 75\% larger organic layer C stores than ancient beech forests, while the total C stock in the soil (organic layer and mineral soil to 100 cm) was similar to 25\% larger in the beech forests due to higher C concentrations in 0-50 cm depth of the mineral soil. The soil stores of N-tot were similar to 50\% and the exchangeable Ca, K and Mg pools about three times larger under beech than under the pine stands. Resin-exchangeable P was enriched in the soils under ancient pine stands probably due to manuring in the past. After clear-cut and long cultivation, it may take >230 years of forest presence to restore the greatly reduced mineral soil C and N pools. The C and N sequestration potential of the soils appeared to be particularly small under pine indicating a pronounced tree species (pine vs. beech) effect on soil C and N dynamics. We conclude that, in the face of rising greenhouse gas emissions, the limited soil C and nutrient storage potential of Scots pine plantations on sandy soils needs consideration when selecting suitable tree species for future forestry. (C) 2013 Elsevier B.V. All rights reserved.}, language = {en} }