科研之友
微信
新浪微博
Facebook
分享链接
摘要
Recovering biodiversity is a common goal during restoration; however, for many ecosystems, it is not well understood how restoration influences species diversity across space and time. I examined understory species diversity and composition after woody encroachment removal in a large-scale savanna restoration experiment in central Iowa, United States. Over a 4-year time series, restoration had profound effects across space and time, increasing richness at local and site-level scales. Restoration sites had increased alpha (within sample) Simpson's diversity and alpha and gamma (site level) species richness relative to control sites, although gamma and beta (among sample) Simpson's diversity, beta richness, and alpha species evenness were not affected. Changes in richness were driven by graminoids at the alpha and gamma scales and woody species (and some evidence for forbs) at the alpha scale. Interestingly, indicator species analysis revealed that at least some species from all functional groups were promoted by restoration, although no species were significant indicators of pre-treatment or control sites. Both savanna and nonsavanna species were indicators of restored sites. Restoration promoted exotic species at both scales, although species with spring phenologies were unaffected. Woody encroachment removal may be a means to promote species establishment in savannas; however, in this study, it resulted in establishment and proliferation of native and exotic and savanna and nonsavanna species. Future work might consider reintroduction of key savanna species to supplement those that have established. Work like this demonstrates the utility of restoration experiments for conducting research on large- and multiscale processes, such as species diversity.
- 出版日期2010-1
