Untitled DocumentEnhancing the Semiarid Ecohydrology Array (SECA) Flux Tower Network
Macro Theme Area:
Basin Scale Water Balance [Project ID: B26]
PI:
Dave Breshears
CO-PI(s):
Travis Huxman, James Hogan
Basin focus:
Regional SW, San Pedro
Specific area in
basin /
field sites:
N/A
Summary/Goals: This project is funded under a Center-Directed Initiatives grant through the Water Sustainability Program and reports on a fiscal year basis.
This project is focused on developing strategic support for the development of the Semiarid Ecohydrology Array (SECA) Flux Tower Network. The SECA flux tower network includes several existing and planned meteorological stations to measure carbon and water flux measurements. The flux tower network can provide critical insights into spatial and temporal variation in ET fluxes across several major ecosystem types.
Activities and outcomes during past year:
Numerous data streams are being collected and data are currently being organized and analyzed to enable effective cross-site comparisons. We enhanced flux tower expertise through training of 3 UA personnel in 2 academic units (School of Natural Resources and Hydrology and Water Resources): 1 PhD Student (J. Villegas), 1 Research Specialist (J. Petti), and 1 Sr. Research Specialist (C. Zou). All three attended a University of Michigan IGERT course in Biosphere-Atmosphere Research and Training. Other faculty and students were briefed on the class and a meeting report summarizing the course is posted on the web
Ph.D Student Juan Villegas coordinated among current SECA participants and reviewed existing flux measurements. He compiled criteria for expanding SECA, which were then used in to guide purchase of 2 additional SECA flux towers acquired with leveraged funds. Villegas also evaluated SECA data streams relative to other related flux data. In addition Villegas also advanced studies of evapotranspiration partitioning that are a central part of the SECA focus. Specifically, he quantified how near-ground incoming solar radiation varies as a function of woody plant density, conducted a pilot study on how evaporation rates vary as a function of woody plant cover and density, and is currently implementing a more comprehensive study to address this issue.
We highlighted SECA and associated research themes in a UA response to a NSF Request for Information related to the development of the National Ecological Observatory Network (NEON). We proposed that UA's Santa Rita Experimental Range be the Core Site for the Desert Southwest Domain of NEON and highlighted ongoing and developing SECA resources. Our proposed site was selected for inclusion in an initial proposal from NEON Inc. to NSF (www.neoninc.org) and could result in a major research focus related to SECA and located and hosted by UA over the next 30 years. Overall, this project has direct importance to Arizona. The vast majority of the water budget leaves as evapotransipration but we do not have a good understanding of differences among ecosystem types or to different precipitation event sites. Management of Arizona's natural resources, including water, requires improved understanding of ecosystem differences and variations in response to precipitation event sizes. This project also enhanced and leveraged the SECA network, largely developed by SAHRA, but does not duplicate ongoing efforts. It also enhanced ongoing collaborations and adds new experimental capability related to the flux tower network.
Plans for the upcoming year:
To overcome these issues we will:
1. Advance cross-site data synthesis by identifying data compilation needs and coordinating plan for planned and additional cross-site flux papers (Identify data synthesis needs: Deliverable 1: summary due September 30)
2. Train up to students and technicians in flux tower measurements through attendance at University of Michigan course this summer (Train 3 post-docs/techs from 2 or more academic units [SNR and EEB targeted]. Deliverable 2: course summary of key points form SNR and EEB trainees: summary due July 31, 2006)
3. Develop and test large-scale rainfall simulation system that can be applied above savanna woodland systems and evaluate potential to measure flux responses (based on Wilcox system at Texas A&M and built largely with Breshears' start-up funds); develop plan for potential application to other SECA sites (Presentation to SECA researchers highlighting use and potential of new rainfall simulation approaches; summary due May 30, 2007).
