Nitrogen enrichment and foliar fungal pathogens affect the mechanisms of multispecies plant coexistence
Changes in resources (e.g. nitrogen) and enemies (e.g. foliar pathogens) are key drivers of plant diversity and composition. However, their effects have not been connected to the niche and fitness differences that determine multispecies coexistence.
Here, we combined a structuralist theoretical approach with a detailed grassland experiment factorially applying nitrogen addition and foliar fungal pathogen suppression to evaluate the joint effect of nitrogen and pathogens on niche and fitness differences, across a gradient from two to six interacting species.
Nitrogen addition and pathogen suppression modified species interaction strengths and intrinsic growth rates, leading to reduced multispecies fitness differences. However, contrary to expected, we also observed that they promote stabilising niche differences. Although these modifications did not substantially alter species richness, they predicted major changes in community composition. Indirect interactions between species explained these community changes in smaller assemblages (three and four species) but lost importance in favour of direct pairwise interactions when more species were involved (five and six).
Altogether, our work shows that explicitly considering the number of interacting species is critical for better understanding the direct and indirect processes by which nitrogen enrichment and pathogen communities shape coexistence in grasslands.
No keywords indexed for this article. Browse by subject →
Peter Chesson
Christopher M. Clark, David Tilman
W. Stanley Harpole, Lauren L. Sullivan, Eric M. Lind et al.
Showing 50 of 77 references
- Published
- Jan 04, 2023
- Vol/Issue
- 237(6)
- Pages
- 2332-2346
- License
- View
You May Also Like
Nate McDowell, William T. Pockman · 2008
3,684 citations
T. P. McGONIGLE, M. H. MILLER · 1990
3,111 citations
Hendrik Poorter, KARL J. NIKLAS · 2011
2,553 citations
Ian J. Wright, Peter B. Reich · 2005
2,502 citations