title: Homogenizing and diversifying effects of intensive agricultural land-use on plant species beta diversity in Central Europe - A call to adapt our conservation measures.
abstract: The prevention of biodiversity loss in agricultural landscapes to protect ecosystem stability and functions is of major importance to stabilize overall diversity. Intense agriculture leads to a loss in species richness and homogenization of species pools, but the processes behind are poorly understood due to a lack of systematic case studies: The specific impacts by agriculture in contrast to other land-use creating open habitat are not studied as such landscapes hardly exist in temperate regions. Applying systematic grids, we compared the plant species distribution at the landscape scale between an active military training areas in Europe and an adjacent rather intensively used agricultural landscape. As the study areas differ mainly in the type of disturbance regime (agricultural vs. non-agricultural), differences in species pattern can be traced back more or less directly to the management. Species trait analyses and multiple measures of beta diversity were applied to differentiate between species similarities between plots, distance-decay, or nestedness. Contrary to our expectation, overall beta diversity in the agricultural area was not reduced but increased under agricultural. This was probably the result of species nestedness due to fragmentation. The natural process of increasing dissimilarity with distance (distance-decay) was suppressed by intense agricultural land-use, generalist and long-distance dispersers gained importance, while rare species lost continuity. There are two independent processes that need to be addressed separately to halt biodiversity loss in agricultural land. There is a need to conserve semi-natural open habitat patches of diverse size to favor poor dispersers and specialist species. At the same time, we stress the importance of mediating biotic homogenization caused by the decrease of distance-decay: The spread of long-distance dispersers in agricultural fields may be acceptable, however, optimized fertilizer input and erosion control are needed to stop the homogenization of environmental gradients due to nitrogen input into semi-natural habitat.
authors: Geoecology/Physical Geography, Institute for Environmental Sciences Landau, University of Koblenz-Landau, Landau, Germany. Electronic address: buhk@uni-landau.de.
authors: Constanze
authors: C
authors: Buhk
authors: Environmental and Soil Chemistry, Institute for Environmental Sciences Landau, University of Koblenz-Landau, Landau, Germany. Electronic address: alt@uni-landau.de.
authors: Martin
authors: M
authors: Alt
authors: Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, 8000 Aarhus, Denmark. Electronic address: Steinbauer@bios.au.dk.
authors: Manuel J
authors: MJ
authors: Steinbauer
authors: Biogeography, University of Bayreuth, Bayreuth, Germany. Electronic address: carl.beierkuhnlein@uni-bayreuth.de.
authors: Carl
authors: C
authors: Beierkuhnlein
authors: US Forest Service, Rocky Mountain Research Station, Provoe, UT, USA. Electronic address: swarren02@fs.fed.us.
authors: Steven D
authors: SD
authors: Warren
authors: Disturbance Ecology, University of Bayreuth, Bayreuth, Germany. Electronic address: anke.jentsch@uni-bayreuth.de.
authors: Anke
authors: A
authors: Jentsch
mesh_terms: D000383:Agriculture; D044822:Biodiversity; D003247:Conservation of Natural Resources; D017753:Ecosystem; D005060:Europe
keywords: Biotic homogenization; Conservation; Dissimilarity; Distance-decay; Intense agricultural land-use; Landscape eutrophication