Plant chemical defense allocation constrains evolution of tolerance to community change across a range boundary

Authors

  • David H. Siemens,

    Corresponding author
    1. Biology, Integrative Genomics Program, Black Hills State University, Spearfish, South Dakota
    • Correspondence

      David H. Siemens, Biology, Integrative Genomics Program, Black Hills State University, 1200 University St., Spearfish, SD 57799-9099. Tel: +1 605-642-6233; Fax: +1 605-642-6273; E-mail: david.siemens@bhsu.edu

    Search for more papers by this author
  • Riston Haugen

    1. Biology, Integrative Genomics Program, Black Hills State University, Spearfish, South Dakota
    Search for more papers by this author

Abstract

Because transplant experiments show that performance usually decreases across species range boundaries, some range limits might develop from factors and processes that prevent adaptation to stressful environments. Here, we determined whether an ecological cost of plant defense involving stress associated with changes in the local plant community may contribute to range limit development in the upland mustard species Boechera stricta. In a common garden experiment of 499 B. stricta plants, performance decreased and a multivariate axis of community structure increased across the boundary, indicating increased stress associated with the community change. There was also significant genetic variation (evolutionary potential) among marker-inferred inbred lines of B. stricta for tolerance to the stress; however, lines with high basal levels of glucosinolate toxins had lower tolerance to the change in community structure. We suggest that defense allocation, which is also needed across the range, may impede adaptation to the stress associated with the community change and thus contribute to range limit development.

Ancillary