Height and clonality traits determine plant community responses to fertilization

Timothy L. Dickson, Gary G. Mittelbach, Heather L. Reynolds, Katherine L. Gross

Research output: Contribution to journalArticle

39 Scopus citations

Abstract

Fertilization via agricultural inputs and nutrient deposition is one of the major threats to global terrestrial plant richness, yet we still do not fully understand the mechanisms by which fertilization decreases plant richness. Tall clonal species have recently been proposed to cause declines in plant species richness by increasing in abundance in response to fertilization and competing strongly with other species. We tested this hypothesis in a fertilization experiment in a low productivity grassland by using a novel experimental manipulation of the presence vs. absence of clonal species and by examining the role of height within these treatments. We found that fertilization decreased species richness more in the presence than absence of clonal species. We also found that only tall species increased in biomass in response to fertilization. In the absence of clonal species, fertilization increased biomass of tall nonclonal species. However, in the presence of clonal species, fertilization decreased tall nonclonal biomass and only tall clonal biomass increased. Fertilization caused almost all short species to be lost in the presence, but not the absence, of clonal species and caused greater declines in the mean and variance of light levels in the presence of clonal species. These results show that the traits of species in a community can determine the magnitude of species loss due to fertilization. The strongly negative effect of tall clonals on species richness in fertilized plots is likely a result of their capacity to decrease light levels to a greater extent and more uniformly than nonclonal species, and thereby drive the exclusion of short species. These results help clarify the mechanisms whereby fertilization decreases grassland plant species richness and suggest that efforts to prevent the loss of species under fertilized conditions may be most effective when they focus on controlling the biomass of tall clonal species.

Original languageEnglish (US)
Pages (from-to)2443-2452
Number of pages10
JournalEcology
Volume95
Issue number9
DOIs
StatePublished - Sep 1 2014

Keywords

  • Biodiversity
  • Biomass production
  • Functional groups
  • Grassland
  • Nitrogen
  • Phosphorus
  • Plant species richness
  • Potassium fertilization
  • Species traits

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

Fingerprint Dive into the research topics of 'Height and clonality traits determine plant community responses to fertilization'. Together they form a unique fingerprint.

  • Cite this