Submitted to: Arizona-Nevada Academy Of Science Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/2002
Publication Date: 12/1/2002
Citation: SNYDER, K.A., GUERTIN, D.P., JEMISON, R.L., FFOLLIOTT, P.F. RIPARIAN PLANT COMMUNITY PATTERNS: A CASE STUDY FROM SOUTHEASTERN ARIZONA. ARIZONA-NEVADA ACADEMY OF SCIENCE JOURNAL. 2002. V. 34(2). P. 106-111. Interpretive Summary: A survey was done to measure what plant species were present and the abundance of each species in different parts of the landscape surrounding a stream in southeastern AZ. The objective was to determine how patterns of plant distribution varied in respect to the influence of the stream. Around streams in arid regions there is a certain sphere of influence, known as the riparian zone, where groundwater and soil moisture are higher than the adjacent upland areas. Due to greater water availability, different plant species may be present in these riparian zones. To conserve these areas, it is important to understand how to identify them by vegetation and, in the absence of vegetation, what other factors may define these areas. We found three distinct community types. These community types appeared to be the result of differences in depth to groundwater. Subtle variations in depth to groundwater explained the variation between mesquite-dominated communities and more water-requiring riparian species, such as sycamore. This research provides valuable information to land managers that need to delineate the boundaries of riparian zones to ensure their effective conservation and management.
Technical Abstract: There is concern about the preservation and, when necessary, restoration of riparian areas in semiarid regions. Understanding patterns of plant species composition and distribution within riparian corridors is helpful in planning for the management and protection of buffer strips that reduce the delivery of sediments to stream systems, maintain streambank stability, and filter excess nutrients that occur in runoff water. To determine how plant community patterns varied along environmental gradients in a semiarid riparian ecosystem, 192 quadrats located on transects radiating away from a mixed perennial and intermittent stream system were sampled for woody and herbaceous plants. Principal Components Analysis (PCA) was used to display community patterns based on species composition and distribution. Three communities of woody plants were observed across hydrologic and elevational gradients: a shrub-dominated Mimosa biuncifera community, a woodland community dominated by Prosopis velutina, and a riparian community dominated by Platanus wrightii. Patterns of herbaceous plants were not related to these gradients.