TY - JOUR A1 - Klaus, Valentin H. A1 - Kleinebecker, Till A1 - Hoelzel, Norbert A1 - Bluethgen, Nico A1 - Boch, Steffen A1 - Müller, Jörg A1 - Socher, Stephanie A. A1 - Prati, Daniel A1 - Fischer, Markus T1 - Nutrient concentrations and fibre contents of plant community biomass reflect species richness patterns along a broad range of land-use intensities among agricultural grasslands JF - Perspectives in plant ecology, evolution and systematics N2 - 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. KW - Biodiversity exploratories KW - Fertilization KW - Grazing KW - Land use KW - Mowing KW - Nitrogen KW - Nutrient limitation KW - Phosphorus KW - Productivity Y1 - 2011 U6 - https://doi.org/10.1016/j.ppees.2011.07.001 SN - 1433-8319 VL - 13 IS - 4 SP - 287 EP - 295 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 -