Exploratory Water Budget Analysis of A Transitional Premontane Cloud Forest in Costa Rica Through Undergraduate Research
Abstract
The ecohydrology of transitional premontane cloud forests is not well understood. This problem is being addressed by a NSF Research Experience for Undergraduates (REU) study at the Texas A&M University Soltis Center for Research & Education in Costa Rica. Exploratory analysis of the water budget within a 20-ha watershed was used to connect three faculty-mentored research areas in ecohydrology, climate, and soil sciences and highlight the roles of 12 undergraduate researchers from 12 different universities. The water budget model is Q = Pn - E - T + ΔG + ΔS where Q = runoff, Pn = net precipitation, E = evaporation, T = transpiration, and ΔG and ΔS are change in groundwater soil water storage, respectively. Additionally, Pn = Pg - I = Tf + Sf + D, where Pg = gross precipitation, I/ΔI = canopy interception or storage, Tf = throughfall, Sf = stemflow, and D = canopy drip. The following terms were well understood Pg (satellite = 34-mm and tower = 38.1-mm) and Q from a recently constructed v-notch weir. We moderately understand Tf + D (30.9-mm from an array of forest rain gages), ΔI (7.2-mm) related to Sf, and T (10.4-mm measured with sapflow sensors). We found that soils were clay loam to silty loam textured Andisols on saprolitic tuft with a mean potential ΔS of 398 mm H2O under laboratory conditions, but in the field the following terms are almost completely unknown and require further field studies including E, ΔG, and ΔS. Recent installation of piezometers will address ΔG. Temporal scaling of measurements to a 1-week period was a challenge as well as the construction, deployment and calibration of instruments. However, this exploration allowed us to determine measurement uncertainties in the water budget, e.g., E, and to set future areas of research to address these uncertainties.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFMED23B0752W
- Keywords:
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- 0439 BIOGEOSCIENCES / Ecosystems;
- structure and dynamics;
- 0850 EDUCATION / Geoscience education research;
- 1800 Hydrology;
- 1813 Eco-Hydrology