PARENT SESSION
Poster Session #24: Modeling.
Tuesday, August 6. Presentation from 5:00 PM to 6:30 PM. Exhibit Hall B & C, TCC

Modeling the influence of climatic change on riparian vegetation along the San Pedro River, Arizona.

DIXON, MARK^*,1, STROMBERG, JULIET¹, DAVID, JOHN¹, ¹ Arizona State University, Tempe, AZ

ABSTRACT- Riparian ecosystems are sensitive to changes in hydrology induced by climatic change or human management of water resources. In the arid Southwest, riparian ecosystems may be particularly sensitive to shifts in the magnitude and seasonality of precipitation (and floods) and the availability of groundwater. We are developing a simulation model to assess the potential impacts of climatic change and groundwater pumping on riparian vegetation along the San Pedro River (southeastern Arizona, USA), one of the last free-flowing rivers in the Southwest and an important migratory corridor for neotropical migrant birds. Our model will link the dynamics of riparian cover types (Populus fremontii - Salix gooddingi forests, Tamarix and Prosopis velutina woodlands, Sporobolus wrightii grasslands, etc.) to spatial and temporal changes in groundwater levels, precipitation, flooding, and fire regimes. Physical drivers for the vegetation model will come from regional climate change projections, simulated flood and fire regimes, alternative development scenarios, and an existing model of groundwater hydrology for the basin. Vegetation response will be modeled according to species life history characteristics and empirical bio-hydrology relationships. Impacts on bird populations will be assessed by linking projections of vegetation change with habitat suitability models for selected resident and migrant songbirds. These models will provide valuable tools for assessing the impacts of climatic and development changes on the San Pedro ecosystem, communicating these projections to stakeholders, and identifying research needs.

KEY WORDS: climate change, riparian vegetation, Southwest, modeling