Thursday, August 9, 2007

PS 67-139: What beetles, bees, and birds can tell us about variability in response to riparian restoration

Gregory H. Golet, The Nature Conservancy, Thomas Gardali, PRBO Conservation Science, Helen Swagerty, River Partners, and Neal M. Williams, Bryn Mawr College.

Observed patterns in restoration response studies may be caused by many factors in addition to implemented restoration actions. And the already difficult task of understanding these patterns is made even more difficult when multiple taxa are studied, as different species respond to different factors in different ways.  As one part of our overall effort to better understand how the Sacramento River ecosystem is responding to implemented restoration actions, we conducted a cross-taxa comparison to characterize variability in restoration response.  We did this by comparing species abundance and richness data collected on bees, beetles and landbirds at a set of riparian restoration sites that span 71 river miles on the Sacramento River.  Our analyses suggest that some taxa are inherently more variable than others in how they respond to restoration.  In addition, we found that restoration success varied depending upon both the year and season in which taxa were studied.  The performance of individual sites relative to one another was not always consistent from year to year, and in general restoration sites had higher seasonal variability in response measures than the remnant habitats to which they were compared.  Finally, we determined that different taxa do not always vary consistently among sites in restoration response, such that knowing how one taxonomic group responded did not necessarily allow us to predict how other taxa faired.  The results of our cross-taxa comparisons have implications for the development and implementation of restoration monitoring programs.