Resource heterogeneity, soil fertility, and species diversity: Effects of clonal species on plant communities

J. Alexander Eilts, Gary G. Mittelbach, Heather L. Reynolds, Katherine L. Gross

Research output: Contribution to journalArticlepeer-review

66 Scopus citations

Abstract

Spatial heterogeneity in soil resources is widely thought to promote plant species coexistence, and this mechanism figures prominently in resource-ratio models of competition. However, most experimental studies have found that nutrient enhancements depress diversity regardless of whether nutrients are uniformly or heterogeneously applied. This mismatch between theory and empirical pattern is potentially due to an interaction between plant size and the scale of resource heterogeneity. Clonal plants that spread vegetatively via rhizomes or stolons can grow large and may integrate across resource patches, thus reducing the positive effect of small-scale resource heterogeneity on plant species richness. Many rhizomatous clonal species respond strongly to increased soil fertility, and they have been hypothesized to drive the descending arm of the hump-shaped productivity-diversity relationship in grasslands. We tested whether clonals reduce species richness in a grassland community by manipulating nutrient heterogeneity, soil fertility, and the presence of rhizomatous clonal species in a 6-year field experiment.We found strong and consistent negative effects of clonals on species richness. These effects were greatest at high fertility and when soil resources were applied at a scale at which rhizomatous clonals could integrate across resource patches. Thus, we find support for the hypothesis that plant size and resource heterogeneity interact to determine species diversity.

Original languageEnglish (US)
Pages (from-to)574-588
Number of pages15
JournalAmerican Naturalist
Volume177
Issue number5
DOIs
StatePublished - May 1 2011

Keywords

  • Clonal plants
  • Coexistence
  • Fertility
  • Nutrient enhancement
  • Resource heterogeneity
  • Species diversity

Fingerprint Dive into the research topics of 'Resource heterogeneity, soil fertility, and species diversity: Effects of clonal species on plant communities'. Together they form a unique fingerprint.

Cite this