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- Info
Species composition along a gradient of urbanization in the lower Sonoran Desert, Arizona, USA
| Author: |
Green, Douglas M.; Baker, Michael G. |
| Date: |
1997 |
| Periodical: |
In: Brock, J.H.; Wade, P.; Pysek, P.; Green, D., eds. Plant Invasions: Studies from North America and Europe. Leiden, The Netherlands: Backhuys Publishers |
| Abstract: |
Urban expansion into wildlands has reduced and fragmented formerly contiguous habitats. Embedded within the urban matrix are newly formed habitat islands in a fragmented riparian ecosystem. Although these islands are riparian in floristic and physiognomic character, their function as habitat is not well understood. We assessed plant species composition of riparian habitats along a gradient of increasing urbanization within the city limits of Phoenix, Arizona, USA. Herbaceous plant. composition was quantified by species frequency and cover. Woody vegetation was quantified on the basis of density, height, and canopy volume. We identified a total of 69 species of which 19 or 27% were introduced. Urban communities had significantly higher richness of introduced shrubs and trees. Overall diversity (H') was 2.0674. The urban wash site had the highest total species richness and diversity, however these values were inflated by a larger component of introduced species. Diversity ranged from 2.1680 in the urban sites to 1.6725 in the margin sites and 2.0566 in the rural sites. Volume and density of tree and shrub canopies were significantly higher in the margin communities. We feel the impacts of urbanization upon riparian habitats could be reduced by proper urban planning and implementation of active habitat management strategies aimed at maintaining landscape mosaics and function. |
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