Climatic extremes lead to species-specific legume facilitation in an experimental temperate grassland
Nitrogen-fixing legumes are key species in grassland ecosystems, as their ability to fix atmospheric nitrogen can facilitate neighboring plants. However, little is known about the fate of this legume effect in the face of extreme weather events, which are increasingly expected to occur.
Here, we examined experimentally how the presence of a legume modifies above-ground net primary production (ANPP) and nitrogen supply of neighboring non-legumes under annually recurrent pulsed drought and heavy rainfall events by comparing responses of three key species in European grassland versus without legume presence over 4 years.
Legume presence facilitated community productivity of neighboring non-legumes under ambient weather conditions and also under experimental heavy rainfall. However, no facilitation of community productivity by the legume was found under experimental drought. Productivity of the three target species responded species-specifically to legume presence under different weather conditions: Holcus lanatus was facilitated only under control conditions, Plantago lanceolata was facilitated only under heavy rainfall, and Arrhenatherum elatius was facilitated irrespective of climate manipulations. The legume effects on δ 15N, leaf N concentration, and N uptake were also species-specific, yet irrespective of the climate manipulations. The data suggest that the missing legume effect on community productivity under the pulsed drought was rather caused by reduced N-uptake of the target species than by reduced N-fixation by the legume.
In contrast to heavy rain, the presence of a legume could not effectively buffer community ANPP against the negative effects of extreme drought events in an experimental temperate grassland. Facilitation also depends on the key species that are dominating a grassland community.
Keywords15N natural abundance Biomass production Mesic Plant-plant interactions Precipitation Species-specific traits Water stress
Above-ground net primary production
Arrhenatherum elatius (L.) P. Beauv. ex J. Presl & C. Presl
Geranium pratense L.
Holcus lanatus L.
Lotus corniculatus L.
- Legume neighbors
A single mixture of three target non-legumes grown in the presence of a legume forb (L. corniculatus)
- Non-legume neighbors
A single mixture of three target non-legumes grown in the presence of a non-legume forb (G. pratense)
Plantago lanceolata L.
Research funding was provided by the German Science Foundation (DFG), by the “Bavarian Climate Programme 2020” within the framework of the research cooperation FORKAST, and research stay of first author was supported by German Academic Exchange Service (DAAD). We thank the Helmholtz Center for Environmental Research for providing lab space for isotope measurements and the German Weather Service for long-term precipitation data, and the Ecological Botanical Garden of University of Bayreuth and the Bayreuth Center for Ecology and Environmental Research (BayCEER) for providing continuous support. We are also grateful to Andrey Malyshev for language correction and to anonymous reviewers for their useful comments on the initial version of the manuscript.
- Beierkuhnlein C, Jentsch A (2005) Ecological importance of species diversity. A review on the ecological implications of species diversity in plant communities. In: Henry R (ed) Plant diversity and evolution: genotypic and phenotypic variation in higher plants. CAB International, Wallingford, pp 249–285CrossRefGoogle Scholar
- Faraway JJ (2005) Linear models with R. Chapman & Hall/CRC, Boca Raton, pp 1–242Google Scholar
- IPCC (2012) Summary for policymakers. In: Field CB, Barros V, Stocker TF, Qin D, Dokken DJ, Ebi KL, Mastrandrea MD, Mach KJ, Plattner GK, Allen SK, Tignor M, Midgley PM (eds) Managing the risks of extreme events and disasters to advance climate change adaptation. A special report of working groups I and II of the intergovernmental panel on climate change. Cambridge University Press, Cambridge and New York, pp 1–19Google Scholar
- Jentsch A, Kreyling J, Elmer M, Gellesch E, Glaser B, Grant K, Hein R, Lara M, Mirzae H, Nadler SE, Nagy L, Otieno D, Pritsch K, Rascher U, Schädler M, Schloter M, Singh BK, Stadler J, Walter J, Wellstein C, Wöllecke J, Beierkuhnlein C (2011) Climate extremes initiate ecosystem regulating functions while maintaining productivity. J Ecol 99:689–702CrossRefGoogle Scholar
- Kutschera L, Lichtenegger E, Sobotik M (2009) Wurzelatlas der Kulturpflanzen gemäßigter Gebiete mit Arten des Feldgemüsebaues. DLG-Verlag, Frankfurt am MainGoogle Scholar
- Morales M, R Development Core Team (2012) sciplot: scientific graphing functions for factorial designs. R package version 1.0-9Google Scholar
- Pinheiro J, Bates D, DebRoy S, Sarkar D, the R Development Core Team (2012) nlme: linear and nonlinear mixed effects models. R package version 3.1-104Google Scholar
- R Development Core Team (2011) R: a language and environment for statistical computing, R version 2.13.2. R foundation for statistical computing, ISBN: 3-900051-07-0, Vienna, Austria. URL http://www.Rproject.org/
- Sadale AN, Karadge BA (2010) Effect of water stress on some morphological characters and nitrogen metabolism in Sesbania grandiflora (L.) Poir. Adv Plant Sci 23:505–509Google Scholar
- Serraj R, Sinclair TR, Purcell LC (1999) Symbiotic N2 fixation response to drought. J Exp Bot 50:143–155Google Scholar
- Spehn EM, Scherer-Lorenzen M, Schmid B, Hector A, Caldeira MC, Dimitrakopoulos PG, Finn JA, Jumpponen A, Ódonnavan G, Pereira JS, Schulze E-D, Troumbis AY, Körner C (2002) The role of legumes as a component of biodiversity in a cross-European study of grassland biomass nitrogen. Oikos 98:205–218CrossRefGoogle Scholar
- Witty JF, Minchin FR, Skøt L, Sheehy JE (1986) Nitrogen fixation and oxygen in legume root nodules. Oxf Surv Plant Mol Cell Biol 3:275–314Google Scholar
- Yang Y, Fang J, Ma W, Wang W (2008) Relationship between variability in aboveground net primary production and precipitation in global grasslands. Geophys Res Lett 35:1–4Google Scholar