Ecotypic diversity of a dominant grassland species resists exotic invasion
Yang, Callaway, Atwater
In this study, Lixue Yang showed that bluebunch wheatgrass (Pseudorogneria spicata) populations with greater within species diversity were pound-for-pound more resistant to invasion by spotted knapweed (Centaurea stoebe) than populations with less species diversity, by an order of magnitude.
Dr. Yang attributed this to two processes: 1) as seen in our previous study, more diverse bluebunch populations had greater yield, and 2) even accounting for their increased yield, diverse populations were more resistant to invasion than suspected.
The causes of this phenomenon remain mysterious, but they may have something to do with root recognition among related bluebunch or with activity of soil communities.
This paper takes an important step towards demonstrating the extreme–yet cryptic–effects that within-species diversity has on plant communities.