TY - JOUR A1 - Blüthgen, Nico A1 - Dormann, Carsten F. A1 - Prati, Daniel A1 - Klaus, Valentin H. A1 - Kleinebecker, Till A1 - Hoelzel, Norbert A1 - Alt, Fabian A1 - Boch, Steffen A1 - Gockel, Sonja A1 - Hemp, Andreas A1 - Müller, Jörg A1 - Nieschulze, Jens A1 - Renner, Swen C. A1 - Schöning, Ingo A1 - Schumacher, Uta A1 - Socher, Stephanie A. A1 - Wells, Konstans A1 - Birkhofer, Klaus A1 - Buscot, Francois A1 - Oelmann, Yvonne A1 - Rothenwöhrer, Christoph A1 - Scherber, Christoph A1 - Tscharntke, Teja A1 - Weiner, Christiane N. A1 - Fischer, Markus A1 - Kalko, Elisabeth K. V. A1 - Linsenmair, Karl Eduard A1 - Schulze, Ernst-Detlef A1 - Weisser, Wolfgang W. T1 - A quantitative index of land-use intensity in grasslands integrating mowing, grazing and fertilization JF - Basic and applied ecology : Journal of the Gesellschaft für Ökologie N2 - 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. KW - Agro-ecosystems KW - Biodiversity exploratories KW - Grassland management KW - Land-use impacts KW - Livestock density KW - Meadows KW - Nitrogen KW - Pastures Y1 - 2012 U6 - https://doi.org/10.1016/j.baae.2012.04.001 SN - 1439-1791 VL - 13 IS - 3 SP - 207 EP - 220 PB - Elsevier CY - Jena ER - TY - JOUR A1 - Klaus, Valentin H. A1 - Kleinebecker, Till A1 - Boch, Steffen A1 - Müller, Jörg A1 - Socher, Stephanie A. A1 - Prati, Daniel A1 - Fischer, Markus A1 - Hoelzel, Norbert T1 - NIRS meets Ellenberg's indicator values prediction of moisture and nitrogen values of agricultural grassland vegetation by means of near-infrared spectral characteristics JF - Ecological indicators : integrating monitoring, assessment and management N2 - 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. KW - Biodiversity exploratories KW - Cover-weighting KW - Near-infrared reflectance spectroscopy (NIRS) KW - Nitrogen KW - Nutrient concentrations KW - Phosphorus Y1 - 2012 U6 - https://doi.org/10.1016/j.ecolind.2011.07.016 SN - 1470-160X VL - 14 IS - 1 SP - 82 EP - 86 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Müller, Jörg A1 - Klaus, Valentin H. A1 - Kleinebecker, Till A1 - Prati, Daniel A1 - Hölzel, Norbert A1 - Fischer, Markus T1 - Impact of Land-Use intensity and productivity on bryophyte diversity in agricultural grasslands JF - PLoS one N2 - While bryophytes greatly contribute to plant diversity of semi-natural grasslands, little is known about the relationships between land-use intensity, productivity, and bryophyte diversity in these habitats. We recorded vascular plant and bryophyte vegetation in 85 agricultural used grasslands in two regions in northern and central Germany and gathered information on land-use intensity. To assess grassland productivity, we harvested aboveground vascular plant biomass and analyzed nutrient concentrations of N, P, K, Ca and Mg. Further we calculated mean Ellenberg indicator values of vascular plant vegetation. We tested for effects of land-use intensity and productivity on total bryophyte species richness and on the species richness of acrocarpous (small & erect) and pleurocarpous (creeping, including liverworts) growth forms separately. Bryophyte species were found in almost all studied grasslands, but species richness differed considerably between study regions in northern Germany (2.8 species per 16 m(2)) and central Germany (6.4 species per 16 m(2)) due environmental differences as well as land-use history. Increased fertilizer application, coinciding with high mowing frequency, reduced bryophyte species richness significantly. Accordingly, productivity estimates such as plant biomass and nitrogen concentration were strongly negatively related to bryophyte species richness, although productivity decreased only pleurocarpous species. Ellenberg indicator values for nutrients proved to be useful indicators of species richness and productivity. In conclusion, bryophyte composition was strongly dependent on productivity, with smaller bryophytes that were likely negatively affected by greater competition for light. Intensive land-use, however, can also indirectly decrease bryophyte species richness by promoting grassland productivity. Thus, increasing productivity is likely to cause a loss of bryophyte species and a decrease in species diversity. Y1 - 2012 U6 - https://doi.org/10.1371/journal.pone.0051520 SN - 1932-6203 VL - 7 IS - 12 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Socher, Stephanie A. A1 - Prati, Daniel A1 - Boch, Steffen A1 - Müller, Jörg A1 - Klaus, Valentin H. A1 - Hölzel, Norbert A1 - Fischer, Markus T1 - Direct and productivity-mediated indirect effects of fertilization, mowing and grazing on grassland species richness JF - The journal of ecology N2 - Recent declines in biodiversity have given new urgency to questions about the relationship between land-use change, biodiversity and ecosystem processes. Despite the existence of a large body of research on the effects of land use on species richness, it is unclear whether the effects of land use on species richness are principally direct or indirect, mediated by concomitant changes in ecosystem processes. Therefore, we compared the direct effects of land use (fertilization, mowing and grazing) on species richness with indirect ones (mediated via grassland productivity) for grasslands in central Europe. We measured the richness and above-ground biomass in 150 grassland plots in 3 regions of Germany (the so-called Biodiversity Exploratories). We used univariate and structural equation models to examine direct and indirect land-use effects. The direct effects of mowing (-0.37, effect size) and grazing (0.04) intensity on species richness were stronger compared with the indirect effects of mowing (-0.04) and grazing (-0.01). However, the strong negative effect of fertilization (-0.23) on species richness was mainly indirect, mediated by increased productivity compared with the weak direct negative effect (-0.07). Differences between regions in land-use effects showed five times weaker negative effects of mowing (-0.13) in the region with organic soils (Schorfheide-Chorin), strong overall negative effects of grazing (-0.29) for the region with organic soils opposed to a similar strong positive effect (0.30) in the Hainich-Dun region, whereas the Schwabische Alb region displayed a five times weaker positive effect (0.06) only. Further, fertilization effects on species richness were positive (0.03) for the region with organic soils compared to up to 25 times stronger negative effects in the other two regions. Synthesis. Our results clearly show the importance of studying both direct and indirect effects of land-use intensity. They demonstrate the indirect nature, via productivity, of the negative effect of fertilization intensity on plant species richness in the real-world context of management-induced gradients of intensity of fertilization, mowing and grazing. Finally, they highlight that careful consideration of regional environments is necessary before attempting to generalize land-use effects on species diversity. KW - biodiversity KW - determinants of plant community diversity and structure KW - ecosystem functioning KW - functional plant group KW - land use KW - productivity KW - species richness KW - structural equation modelling Y1 - 2012 U6 - https://doi.org/10.1111/j.1365-2745.2012.02020.x SN - 0022-0477 VL - 100 IS - 6 SP - 1391 EP - 1399 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Türke, Manfred A1 - Andreas, Kerstin A1 - Gossner, Martin M. A1 - Kowalski, Esther A1 - Lange, Markus A1 - Boch, Steffen A1 - Socher, Stephanie A. A1 - Müller, Jörg A1 - Prati, Daniel A1 - Fischer, Markus A1 - Meyhöfer, Rainer A1 - Weisser, Wolfgang W. T1 - Are gastropods, rather than ants, important dispersers of seeds of myrmecochorous forest herbs? JF - The American naturalist : a bi-monthly journal devoted to the advancement and correlation of the biological sciences N2 - Seed dispersal by ants (myrmecochory) is widespread, and seed adaptations to myrmecochory are common, especially in the form of fatty appendices (elaiosomes). In a recent study, slugs were identified as seed dispersers of myrmecochores in a central European beech forest. Here we used 105 beech forest sites to test whether myrmecochore presence and abundance is related to ant or gastropod abundance and whether experimentally exposed seeds are removed by gastropods. Myrmecochorous plant cover was positively related to gastropod abundance but was negatively related to ant abundance. Gastropods were responsible for most seed removal and elaiosome damage, whereas insects (and rodents) played minor roles. These gastropod effects on seeds were independent of region or forest management. We suggest that terrestrial gastropods can generally act as seed dispersers of myrmecochorous plants and even substitute myrmecochory, especially where ants are absent or uncommon. KW - myrmecochory KW - gastropodochory KW - Arion KW - slug KW - seed dispersal Y1 - 2012 U6 - https://doi.org/10.1086/663195 SN - 0003-0147 VL - 179 IS - 1 SP - 124 EP - 131 PB - Univ. of Chicago Press CY - Chicago ER -