Estimating effects of nitrogen (N) deposition is essential for understanding human impacts on biodiversity. However, studies relating atmospheric N deposition to plant diversity are usually restricted to small plots of high conservation value. Here, we used data on 381 randomly selected 1 km2 plots covering most habitat types of Central Europe and an elevational range of 2900 m. We found that high atmospheric N deposition was associated with low values of six measures of plant diversity. The weakest negative relation to N deposition was found in the traditionally measured total species richness. The strongest relation to N deposition was in phylogenetic diversity, with an estimated loss of 19% due to atmospheric N deposition as compared with a homogeneously distributed historic N deposition without human influence, or of 11% as compared with a spatially varying N deposition for the year 1880, during industrialization in Europe. Because phylogenetic plant diversity is often related to ecosystem functioning, we suggest that atmospheric N deposition threatens functioning of ecosystems at the landscape scale.
swissBDM
This file contains the six measures of plant diversity for each of the 381 study plots, each of 1 km2 size, as obtained from the Swiss biodiversity monitoring indicator "species richness in landscapes" (www.biodiversitymonitoring.ch/en/data/indicators/z/z7.html). Additionally, the file contains the estimated atmospheric N deposition for each plot as well as the different covariates as obtained from [1]. The content of the columns is as follows: PLOT_ID: Unique identifier for each 1 km2 plot. TOTAL_SR: Number of recorded species. OLIGO_SR: Number of species typically found on nutrient-poor soils, i.e. oligotrophic species with N-values of one and two [2]. AGRI_SR : Number of target species for which Swiss agriculture has particular responsibility of conservation [3]. UNIQUE: Community uniqueness calculated as the average Simpson dissimilarity index [4] of species composition for the particular study plot paired with each other plot. FD: Functional diversity. PD :Phylogenetic diversity. Ndep: Atmospheric Nitrogen deposition (kg ha-1 yr-1). E.avg: Altitude (m.a.s.l.). L.agrilow: Lowland agricultural area (ha). L.tree: Open woody formation area (ha). CALC: Calcareous substrate (%). TR.ran: Range of temperature variation Jul.-Jan. (°C).
creek.sd: Standard deviation of creek length (m). REFERENCES: [1] Wohlgemuth, T., Nobis, M.P., Kienast, F. & Plattner, M. 2008 Modelling vascular plant diversity at the landscape scale using systematic samples. J. Biogeogr. 35, 1226-1240. (doi:j.1365-2699.2008.01884.x). [2] Landolt, E., Bäumler, B., Erhardt, A., Hegg, O., Klötzli, F., Lämmler, W., Nobis, M., Rudmann-Maurer, K., Schweingruber, F. & Theurillat, J. 2010 Flora Indicativa, Ecological Indicator Values and Biological Attributes of the Flora of Switzerland and the Alps. Bern, Haupt-Verlag; 382 p. [3] BAFU & BLW. 2008 Umweltziele Landwirtschaft. Hergeleitet aus bestehenden rechtlichen Grundlagen. Bern, Bundesamt für Umwelt; 221 p. [4] Koleff, P., Gaston, K.J. & Lennon, J.J. 2003 Measuring beta diversity for presence-absence data. J. Anim. Ecol. 72, 367-382. (doi:10.1046/J.1365-2656.2003.00710.x).
