PARENT SESSION
Poster Session #30: Long-Term Ecological Research.
Wednesday, August 8, 2001. Presentation from 3:30 PM to 5:00 PM. Exhibition Hall

Analysis of Sonoran desert vegetation in the CAP-LTER study area, Phoenix, AZ.

Stiles, Arthur¹, Gries, Corinna¹, Scheiner, Samuel², ^{1 2}

ABSTRACT- In accordance with its mission to study the ecological characteristics of a large urban center, the CAP-LTER has undertaken a large scale sampling of the Phoenix metropolitan area and the surrounding landscape. A sample point was randomly assigned within each of two hundred grid cells established over the study area. Data collected at each point includes information describing the plants, arthropods, birds, soils, and human influences within a 900 m2 quadrat. This poster presents the results of analyses conducted on woody plant data collected in undeveloped desert locales. NMS ordination was used to generate graphs of species similarity between site groupings. These groups include: outlying areas versus remnant patches, disturbed versus non-disturbed areas, habitat types (i.e. flats, washes, slopes), and Arizona Upland versus Lower Colorado River provinces of the Sonoran desert. Additionally, classification techniques were used in order to delineate community types. It was found that habitat type, disturbance status, and province identity influences mean species richness. According to the ordination graphs, habitat type and location relative to the urban fringe produced a high degree of clustering in at least some of the groups; province had slight clustering, whereas disturbance showed no evidence of clustering. This poster demonstrates that urban areas need not be ignored by ecologists. Meaningful ecological comparisons can be made within this system.

KEY WORDS: Sonoran desert, urban ecology, woody plants, CAP-LTER