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Seasonal and interannual variation in water vapor fluxes and energy balance in a moist mixed grassland

Fluxes of sensible and latent heat were measured over a grassland during 1998 and 1999 using the eddy covariance technique. The study objectives were to document seasonal and interannual variation evapotranspiration. Bowen ratios were lower in 1998 (0.5-3.0) than in 1999 (2.5-8.5) due to lower evapotranspiration rates (E). Maximum E also occurred later in 1998 than in 1999; Day 188 (10.4 mmol m-2s-1) versus Day 152 (5.6 mmol m-2s-1). Daily evapotranspiration rates were positively correlated with net radiation, canopy conductance, plant nitrogen content, leaf area index and soil moisture. Based on calculations of the decoupling coefficient (O). evapotranspiration was more constrained by canopy conductance in 1999 (O<0.2) than in 1998 (O>0.3). Evapotranspiration and energy partitioning in this grassland were sensitive to seasonal changes in soil moisture and interannaual variation in spring precipitation. Annual evapotranspiration was 300 mm. / x, 70 leaves : ill. ; 28 cm.

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:ALU.w.uleth.ca/dspace#10133/124
Date January 2001
CreatorsWever, Linda A., University of Lethbridge. Faculty of Arts and Science
ContributorsFlanagan, Lawrence
PublisherLethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2001, Arts and Science, Department of Biological Sciences
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
Languageen_US
Detected LanguageEnglish
TypeThesis
RelationThesis (University of Lethbridge. Faculty of Arts and Science)

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