Submitted to: American Geophysical Union
Publication Type: Proceedings
Publication Acceptance Date: 10/10/2001
Publication Date: 12/10/2001
Citation: Scott, R.L., Watts, C., Garatuza, J., Edwards, E., Goodrich, D.C., Williams, D. 2001. Measuring the distribution of surface energy and water fluxes in a riparianmesquite savannah-type ecosystem. EOS, Trans. AGU 82(47), Fall Meet. Suppl., Abstract B51A-0164.
Technical Abstract: Eddy flux studies have traditionally focused on total ecosystem exchanges of energy and water by making measurements in the well-mixed surface layer. This approach does not give information about the partitioning of the total ecosystem fluxes between overstory and understory sources and sinks. In the more open canopy environment of a savannah, information about this partitioning of fluxes is often required in order to understand the relative importance and functioning of key ecosystem components. In this paper, we present some results from a series of multinational experiments carried out in a riparian mesquite (Prosopis velutina) forest. Three eddy covariance systems were deployed to measure energy, carbon and water fluxes. One was installed on a tower to measure whole ecosystem fluxes. The other two were installed at a height of 2 m, one in a relatively closed understory patch and the other in a more open understory patch, during periods before and after the onset of the summer rainy season. Our results highlight the fact that the trees had access to groundwater (10 m depth), and thus, they had a water use that was relatively insensitive to local precipitation. In contrast, the contribution of the understory to the total ecosystem fluxes was highly variable due to the presence or absence of precipitation.