• Huxman home

• interests

• projects

• events

• people

• CV

• selected publications

• courses taught

My research program is focused on determining how and when the carbon and water cycles in semi-arid and arid ecosystems are coupled in order to understand functional responses of these systems to variation in precipitation. Embedded in this larger program as more specific attempts to understanding how factors such as vegetation change can influence the relationship among ecosystem processes and change the translation of precipitation into biological activity. We use a series of linked projects, in a coordinated network to tackle these questions. The Southwestern ECohydrology Array (SECA – eebweb.arizona.edu/faculty/huxman/seca/), is a multi-user network that serves to assess biosphere / atmospheric exchange processes, as well as surface hydrology in semi-arid ecosystems. SECA is administered through the University of Arizona ’s Institute for the Study of Planet Earth, the Department of Ecology and Evolutionary Biology, the NSF-Science & Technology Center SAHRA (Sustainability of semi-arid hydrology and riparian areas) and the USDA-ARS Southwestern Watershed Research Center . The array is operated in part by Travis Huxman (EEB), Russell Scott (USDA), David Breshears (ISPE), and Paul Brooks (SAHRA). Components of the array were constructed with funds from the University of Arizona , the National Science Foundation (Division of Environmental Biology), and the USDA. SECA consists of an array of eddy flux towers placed throughout southeastern Arizona in the context of vegetation composition change. At a number of sites within the array, we are manipulating precipitation, both by additions and removals on small plots throughout entire seasons, or by applying ‘pulses’ of precipitation within the open landscape to address specific, short-term questions. These experiments will provide information on the impact of changes in the timing and magnitude of precipitation on the coupling of water and carbon fluxes in arid lands. SECA sites include (1) a comparison of geomorphic surfaces on grassland processes located on the Santa Rita Experimental Range, (2) two ‘woody-plant encroachment’ transects in a riparian and upland setting, and (3) a series of forested systems, including a coniferous tree dominated site on the top of Mt. Lemon .