Soil microbes generate stronger fitness differences than stabilization among California annual plants

Gaurav S. Kandlikar, Xinyi Yan, Jonathan M. Levine, Nathan J.B. Kraft

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Soil microorganisms influence a variety of processes in plant communities. Many theoretical and empirical studies have shown that dynamic feedbacks between plants and soil microbes can stabilize plant coexistence by generating negative frequencydependent plant population dynamics. However, inferring the net effects of soil microbes on plant coexistence requires also quantifying the degree to which they provide one species an average fitness advantage, an effect that has received little empirical attention. We conducted a greenhouse study to quantify microbially mediated stabilization and fitness differences among 15 pairs of annual plants that co-occur in southern California grasslands. We found that although soil microbes frequently generate negative frequencydependent dynamics that stabilize plant interactions, they simultaneously generate large average fitness differences between species. The net result is that if the plant species are otherwise competitively equivalent, the impact of plant-soil feedbacks is to often favor species exclusion over coexistence, a result that becomes evident only by quantifying the microbially mediated fitness difference. Our work highlights that comparing the stabilizing effects of plant-soil feedbacks to the fitness difference they generate is essential for understanding the influence of soil microbes on plant diversity.

Original languageEnglish (US)
Pages (from-to)E30-E39
JournalAmerican Naturalist
Issue number1
StatePublished - Jan 2021

All Science Journal Classification (ASJC) codes

  • Ecology, Evolution, Behavior and Systematics


  • Coexistence
  • Competition
  • Plant-microbe interactions
  • Plant-soil feedbacks
  • Rhizosphere
  • Soil biota


Dive into the research topics of 'Soil microbes generate stronger fitness differences than stabilization among California annual plants'. Together they form a unique fingerprint.

Cite this