Many exotic species have little apparent impact on ecosystem processes, whereas others have dramatic consequences for human and ecosystem health. There is growing evidence that invasions foster eutrophication. We need to identify species that are harmful and systems that are vulnerable to anticipate these consequences. Species’ traits may provide the necessary insights. We conducted a global meta-analysis to determine whether plant leaf and litter functional traits, and particularly leaf and litter nitrogen (N) content and carbon: nitrogen (C : N) ratio, explain variation in invasive species’ impacts on soil N cycling. Dissimilarity in leaf and litter traits among invaded and noninvaded plant communities control the magnitude and direction of invasion impacts on N cycling. Invasions that caused the greatest increases in soil inorganic N and mineralization rates had a much greater litter N content and lower litter C : N in the invaded than the reference community. Trait dissimilarities were better predictors than the trait values of invasive species alone. Quantifying baseline community tissue traits, in addition to those of the invasive species, is critical to understanding the impacts of invasion on soil N cycling.
Bibliographical noteFunding Information:
The study has been supported by the TRY initiative on plant traits (http://www.try-db.org). The TRY initiative and database is hosted, developed and maintained by J. Kattge and G. B?nisch (Max Planck Institute for Biogeochemistry, Jena, Germany). TRY is/has been supported by DIVERSITAS, IGBP, the Global Land Project, the UK Natural Environment Research Council (NERC) through its programme QUEST (Quantifying and Understanding the Earth System), the French Foundation for Biodiversity Research (FRB) and GIS ?Climat, Environnement et Soci?t?? France. M.R.L. received funding from the Garden Club of America Wetlands Scholarship, EPA-Science to Achieve Results Graduate Fellowship F13F31249, NSF-Doctoral Dissertation Improvement Grant 1406809, and NSF DEB 1354879. J.P. acknowledges the European Research Council Synergy grant ERC-2013-SyG-610028 IMBALANCE-P. BY benefited from a postdoctoral fund from the French National Research Agency LabEx ANR-10-LABX-0003-BCDiv, in the context of the ?Investissements d'avenir? ANR-11-IDEX-0004-02. We would also like to thank those who helped improve this manuscript: Cari Ficken, Aspen Reese, Bob Shriver and Rachel Mitchell.
© 2016 The Authors. New Phytologist © 2016 New Phytologist Trust
- functional trait
- leaf carbon to nitrogen
- leaf nitrogen content
- nitrogen cycling
- nutrient-use strategy
- plant invasions