Diversity effects under different nutrient addition and cutting frequency environments in experimental plant communities
The effects of biodiversity on productivity have been well studied in the past decades. However, the responses of these biodiversity effects to modern grassland managements have not been explicitly tested. By establishing a five years diversity-manipulated experiment with different cutting frequency and nutrient addition levels, we explored the changes of biodiversity effects and the underlying mechanisms under these managements. Our results showed that community biomass increased with species richness. The correlations were observed under all management regimes, but their strengths varied with management intensity. The net biodiversity effects (NE) increased with nutrient supply, but reduced with frequent cutting. These two factors also interactively influenced NE. Importantly, their influences could last 5 years or longer. The NE changes mainly resulted from the variations of complementarity effects (CE), i.e., the aboveground space partitioning of our species. However, the selection effects (SE) were minimally influenced by nutrient addition and cutting frequency, indicating that under these conditions our species had comparably competitive strength. Especially, CE increased over time in highly cutting subplots, suggesting that this relationship was condition–dependent. We conclude that biodiversity is vitally important for ecosystem functioning even when the ecosystems are disturbed by human activities, and is most effective in enhancing biomass productivity under nutrient supply and low cutting frequency conditions. Field studies with species that come from other functional groups are needed to draw a more general conclusion.
KeywordsAboveground biomass Complementarity effect Management practice Selection effect Species richness
The study is supported by the National Natural Science Foundation of China granted to Guozhen Du (41430749) and Wei Qi (31600329), and the Fundamental Research Funds for the Central Universities granted to Wei Qi (lzujbky-2016-90). We thank Ang Li, Menghe Gu and other field assistants for their help with field work, and Perfersor Miaojun Ma for his useful suggestions.
- Bissels S, Hölzel N, Otte A (2004) Population structure of the threatened perennial Serratula tinctoria in relation to vegetation and management. Appl Veg Sci 7:267–274Google Scholar
- Bobbink R (1989) Brachypodium pinnatum and the species diversity in chalk grassland. Ph.D. thesis. Utrecht University, Utrecht, The NetherlandsGoogle Scholar
- Fargione J, Tilman D, Dybzinski R, Lambers JHR, Clark C, Harpole WS, Knops JMH, Reich PB, Loreau M (2007) From selection to complementarity: shifts in the causes of biodiversity-productivity relationships in a long-term biodiversity experiment. P Natl Acad Sci USA 274:871–876Google Scholar
- Harpole WS, Sullivan LL, Lind EM, Firn J, Adler PB, Borer ET, Chase J, Fay PA, Hautier Y, Hillebrand H, MacDougall AS, Seabloom EW, Williams R, Bakker JD, Cadotte MW, Chaneton EJ, Chu CJ, Cleland EE, D’Antonio C, Davies KF, Gruner DS, Hagenah N, Kirkman K, Knops JMH, Pierre KJL, McCulley RL, Moore JL, Morgan JW, Prober SM, Rosch AC, Schuetz M, Stevens CJ, Wragg PD (2016) Addition of multiple limiting resources reduces grassland diversity. Nature 537:93–96CrossRefPubMedGoogle Scholar
- Knapp AK, Hoover DL, Blair JM, Buis G, Burkepile DE, Chamberlain A, Collins SL, Fynn RWS, Kirkman KP, Smith MD, Blake D, Govender N, O’Neal P, Schreck T, Zinn A (2012) A test of two mechanisms proposed to optimize grassland aboveground primary productivity in response to grazing. J Plant Ecol 5:357–365CrossRefGoogle Scholar
- R Development Core Team (2013) R: a language and environment for statistical computing. R Foundation for Statistical ComputingGoogle Scholar
- Socher SA, Prati D, Boch S, Müller J, Baumbach H, Gockel S, Hemp A, Schöning I, Wells K, Buscot F, Kalko EKV, Linsenmair KE, Schulze ED, Weisser WW, Fischer M (2013) Interacting effects of fertilization, mowing and grazing on plant species diversity of 1500 grasslands in Germany differ between regions. Basic Appl Ecol 14:126–136CrossRefGoogle Scholar
- Tilman D (1999) The ecological consequences of changes in biodiversity—a search for general principles. Ecology 80:1455–1474Google Scholar