Tama-risk? Avian responses to the invasion of saltcedars (Tamarix ramosissima) in Sonora, Mexico

Abstract

Although exotic plant invasions are one of the most important components of global change, previous studieshave found some of the alien species to provide resources and/or conditions to native biota. One example of this isthe saltcedar (Tamarix ramosissima). This exotic invasive tree has been related to several dramatic environmentalchanges in North America. However, previous studies suggest that they offer resources and conditions for nativebiota, such as the threatened southwestern willow flycatcher (Empidonax traillii). In this study, we surveyed aviancommunities and bird nests at sites severely invaded by saltcedars, moderately invaded sites, and non-invaded sitesin northwestern Mexico. Our results show that although bird species richness and abundances do not differ amongthe studied conditions, species composition did. Also, bird nest density differed among the studied conditions, withnon-invaded sites having the highest functional diversity of nesting birds. We suggest that future studies should gathernatural history and ecological information that allows managing this invasive species correctly both in the USA andMexico.