Evapotranspiration Depletion Of Saltcedar Managed Areas In The New Mexico Arid Environment Along The Rio Grande
Solis, Jose A 1
1 Univerisity of Colorado at Boulder
Many federal, state, and local water management agencies have been extremely concerned with the infestation of this exotic saltcedar (Tamarix spp.) plant due to its reputation for high water consumption and the difficulty and cost involved in its management. Several methods of control have been implemented in an effort to reduce saltcedar evapotranspiration (ET), improve ecological health of riparian regions along the river, and re-establish indigenous plants such as cottonwood, willows and saltgrass among others. Management practices for controlling saltcedar include mechanical, biological, chemical and ecological competitive means.
This study investigated evapotranspiration (ET) depletion of saltcedar managed areas where three common methods i) mowing, ii) herbicide treatment and iii) plowing or clearing have been practiced. The eddy covariance method was used to measure ET at four sites which included Caballo mowed saltcedar site, Monticello herbicide saltcedar treated site, Bosque del Apache National Wildlife Refuge (NWR) plowed or cleared saltcedar site, and Bosque del Apache NWR monotypic dense saltcedar site.
A comparison of mowed, herbicide treated and plowed ET to a dense monotypic saltcedar stand as a baseline resulted in mean ET potential reduction of 25%, 52%, and 30%, respectively. After deducting mean precipitation from the measured ET, assuming all precipitation evaporated, a reduction in ET of 38% was achieved when mowed saltcedar site was compared to the dense site; ET reduction of 66% and 37% was achieved when herbicide treated and plowed sites were compared to dense site.