ARS | Publication request: Vegetation-Hydrology Interactions: Dynamics of Riparian Plant Water Use

Submitted to: Ecology of Desert Riparian Ecosystems: The San Pedro River Example
Publication Type: Book/Chapter
Publication Acceptance Date: May 18, 2006
Publication Date: April 15, 2009
Citation: Williams, D., Scott, R.L. 2009. VEGETATION-HYDROLOGY INTERACTIONS: DYNAMICS OF RIPARIAN PLANT WATER USE. In: Ecology and Conservation of the San Pedro River. Ed. by J. C. Stromberg and B. J. Tellman. Tucson: University of Arizona Press. p. 37-56.

Interpretive Summary: Riparian vegetation intercepts surface and sub-surface water flowing from drainage basins and forms a functionally important interface between terrestrial and aquatic ecosystems. The influence of riparian vegetation on hydrological processes, and conversely, the impact of hydrological processes on riparian vegetation have been the focus of considerable scientific investigation. Through such investigations, ecologists and hydrologists have formed productive, collaborative relationships and together have generated broad conceptual understanding of hydrological factors controlling riparian ecosystem structure and function and associated feedbacks with stream hydrology and geomorphology. This chapter describes the current state of knowledge of vegetation-hydrology interactions in riparian ecosystems of arid and semiarid basins focusing on studies conducted along the Upper San Pedro River in southeastern Arizona. We highlight some key concepts related to the influence of riparian plants on stream hydrology, describe patterns of water use by dominant vegetation communities along the San Pedro River, and evaluate some of the principal methodologies used to make these determinations.

Technical Abstract: Functional dynamics of streamside and floodplain vegetation in semiarid basins are controlled generally by hydrological processes operating at local, landscape and catchment scales. However, the relative importance of the hydrologic and climate factors that drive evapotranspiration (ET) and CO2 exchange in these systems depends on complex interactions between vegetation functional composition, the availability of moisture in deep, unsaturated soil layers, and depth and variability of the near-surface water table. This chapter describes the current state of knowledge of vegetation-hydrology interactions in riparian ecosystems of arid and semiarid basins focusing on studies conducted along the Upper San Pedro River. We highlight some key concepts related to the influence of riparian plants on stream hydrology, describe patterns of water use by dominant vegetation communities along the San Pedro River, and evaluate some of the principal methodologies used to make these determinations.