Untitled DocumentRainout experiments in the Santa Rita range
Macro Theme Area:
River Systems [Project ID: R37]
PI:
Travis Huxman
CO-PI(s):
N/A
Basin focus:
Regional SW
Specific area in
basin /
field sites:
Field sites are located on the Santa Rita Experimental Range
Summary/Goals: This project is aimed at understanding how the water cycle influences the balance between grasses and woody plants in experimental plots on contrasting soil types. We are also carefully evaluating the role of vegetation in influencing the water cycle (soil evaporation, transpiration and infiltration), by using experimental plots under rain-out shelters where precipitation is applied by hand, and whole-plots can be fitted with ecosystem-scale gas exchange chambers. This project is especially well suited to consider how water and carbon cycles are coupled over short (days following rainfall events) and long (seasons entrenched in different rainfall regimes) time periods. A unique aspect of this project is the experimental manipulation of winter and summer precipitation in a factorial setting (increases and decreases independently in winter and summer).
Activities and outcomes during past year:
Data collected from this experiment has resulted in several publications (including a high-profile paper in Nature evaluating cross-biome characteristics of precipitation-use efficiency). We also published a review of the coupling of carbon cycling (at small and large scales) to precipitation events in semi-arid and arid systems, primarily based on the patterns seen in this project.
A 2005/6 outcome of this project is a DOE-NICCR award to Kiona Ogle at the University of Wyoming (with Huxman as a UofA subcontract) to coordinate the synthesis of experimental manipulations of precipitation throughout the water limited western US.
Plans for the upcoming year:
Our only activities will be to carry out the synthesis described above.
Dept. of Ecology and Evol. Biology, Univ. of Tennessee
Organization Involvement:
Jake Weltzin is a co-PI on the collaborative proposal from NSF-Ecology and is responsible for the demographic analysis of woody plant seedling on our plots
