Plant and animal diversity in restored and disturbed reaches along the urbanized Salt River in central Arizona.

Riparian areas provide important ecosystem services. Additional research is needed to determine effective ways to restore services to degraded urban riparian ecosystems and to assess restoration success. The Salt River in the Phoenix metropolitan area (CAP study site) has been altered by upstream damming, flow diversion, stream channelization, and floodplain conversion to urban lands. Portions of the river and its riparian zone have undergone active restoration, some areas have revegetated on their own in response to discharge of perennial water from urban storm drains, and other areas remain degraded with highly intermittent flows. Our project focuses on six, 1-km reaches along the Salt River. We sampled plant and animal communities along three cross-floodplain transects per study reach. At each site, we quantified herpetofauna (amphibians and reptiles) using visual-encounter-surveys in nine 10x20 m plots and surveyed for birds in six 25-m fixed radius, 10-minute point-count-surveys. During spring and summer 2012 surveys, we detected 11 species of herpetofauna and 39 species of birds. Wildlife species richness and abundance was greatest during summer surveys. Preliminary results show that compared to a non-urban reference site, generally herpetile and bird species richness and abundance were lowest in urban degraded sites and similar in active and passively restored perennial-flow sites. Plant cover, by species, was sampled in 30, 1x2m plots distributed along transects. Plant species richness was equally high among sites during the spring sampling, owing to high numbers of cool-season annuals. During the summer dry season, plant species richness was highest at passively restored perennial flow sites, intermediate at the actively restored site and non-urban reference site, and low at the passively restored site with intermittent flow (i.e. the urban degraded site). Our results will provide recommendation to natural resource managers of urban areas relating habitat and wildlife to restoration activities.