TY - JOUR T1 - Increasing effects of chronic nutrient enrichment on plant diversity loss and ecosystem productivity over time JF - Ecology Y1 - 2021 A1 - Seabloom, E.W. A1 - Adler, P.B. A1 - Alberti, J. A1 - Biederman, L. A1 - Buckley, Y.M. A1 - Cadotte, M.W. A1 - S.L Collins A1 - Dee, L. A1 - Fay, P.A. A1 - Firn, J. A1 - Hagenah, N. A1 - Harpole, W. S. A1 - Hautier, Y. A1 - Hector, A. A1 - Hobbie, S.E. A1 - Isbell, F. A1 - Knops, J.M.H. A1 - Kimberly J. Komatsu A1 - Laungani, R. A1 - MacDougall, A. A1 - McCulley, R.L. A1 - Moore, J.L. A1 - Morgan, J.W. A1 - Ohlert, T. A1 - Prober, S.M. A1 - Risch, A.C. A1 - Schuetz, M. A1 - Stevens, C.J. A1 - Borer, E.T. AB -

Human activities are enriching many of Earth’s ecosystems with biologically limiting mineral nutrients such as nitrogen (N) and phosphorus (P). In grasslands, this enrichment generally reduces plant diversity and increases productivity. The widely demonstrated positive effect of diversity on productivity suggests a potential negative feedback, whereby nutrient‐induced declines in diversity reduce the initial gains in productivity arising from nutrient enrichment. In addition, plant productivity and diversity can be inhibited by accumulations of dead biomass, which may be altered by nutrient enrichment. Over longer timeframes, nutrient addition may increase soil fertility by increasing soil organic matter and nutrient pools. We examined the effects of 5‐11 years of nutrient addition at 47 grasslands in twelve countries. Nutrient enrichment increased aboveground live biomass and reduced plant diversity at nearly all sites, and these effects became stronger over time. We did not find evidence that nutrient‐induced losses of diversity reduced the positive effects of nutrients on biomass, however nutrient effects on live biomass increased more slowly at sites where litter was also increasing, regardless of plant diversity. This work suggests that short‐term experiments may underestimate the long‐term nutrient enrichment effects on global, grassland ecosystems.

VL - 102 UR - https://onlinelibrary.wiley.com/doi/10.1002/ecy.3218 IS - 2 ER - TY - JOUR T1 - Soil net nitrogen mineralisation across global grasslands JF - Nature Communications Y1 - 2019 A1 - Risch, A.C. A1 - Zimmermann, S. A1 - Ochoa-Hueso, R. A1 - schütz, M. A1 - Frey, B. A1 - Firn, J. L. A1 - Fay, P. A. A1 - Hagedorn, F. A1 - E.T. Borer A1 - Seabloom, E. W. A1 - Harpole, W. S. A1 - Knops, J. M. H. A1 - McCulley, R. L. A1 - Broadbent, A. A. D. A1 - Stevens, C. J. A1 - Silveira, M. L. A1 - P. Adler A1 - Báez, S. A1 - L.A. Biederman A1 - John M. Blair A1 - Brown, C. S. A1 - Caldeira, M. C. A1 - Scott. L. Collins A1 - Daleo, P. A1 - di Virgilio, A. A1 - Ebeling, A. A1 - Eisenhauer, N. A1 - Esch, E. A1 - Eskelinen, A. A1 - Hagenah, N. A1 - Hautier, Y. A1 - Kirkman, K. P. A1 - MacDougall, A. S. A1 - Joslin L. Moore A1 - Power, S. A. A1 - Prober, S. M. A1 - Roscher, C. A1 - Sankaran, M. A1 - Siebert, J. A1 - Speziale, K. L. A1 - Tognetti, P. M. A1 - Virtanen, R. A1 - Yahdjian, L. A1 - Moser, B. AB -

Soil nitrogen mineralisation (Nmin), the conversion of organic into inorganic N, is important for productivity and nutrient cycling. The balance between mineralisation and immobilisation (net Nmin) varies with soil properties and climate. However, because most global-scale assessments of net Nmin are laboratory-based, its regulation under field-conditions and implications for real-world soil functioning remain uncertain. Here, we explore the drivers of realised (field) and potential (laboratory) soil net Nmin across 30 grasslands worldwide. We find that realised Nmin is largely explained by temperature of the wettest quarter, microbial biomass, clay content and bulk density. Potential Nmin only weakly correlates with realised Nmin, but contributes to explain realised net Nmin when combined with soil and climatic variables. We provide novel insights of global realised soil net Nmin and show that potential soil net Nmin data available in the literature could be parameterised with soil and climate data to better predict realised Nmin.

VL - 10 UR - http://www.nature.com/articles/s41467-019-12948-2 IS - 4981 ER -