A Preliminary Quantification of the Impacts of Aspen to Conifer Succession on Water Yield Within the Colorado River Basin (A Process Aggravating the Salt Pollution …
Citation
William Humphries, Gerald F Gifford, and Richard A Jaynes, A Preliminary Quantification of the Impacts of Aspen to Conifer Succession on Water Yield Within the Colorado River Basin (A Process Aggravating the Salt Pollution …: .
Summary
Quaking aspen cover 3.3 million hectares in the Upper Colorado River Basin, and these areas are gradually converting to conifer forest by the natural process of ecological succession. This change is being hastened by forest managment practices that reduce fires, destroy pests, or otherwise prevent the natural processes that previously caused conifer areas to revert to the subclimax aspen. The hydrologic consequence has been forecast to cause a runoff reduction in the Colorado River as large as one million acre-feet annually, a major blow to water availability in the Lower Basin. Understanding and dealing with the problems requires quantitative comparision of the evaportranspiration rates of conifer and aspen forests under a variety [...]
Summary
Quaking aspen cover 3.3 million hectares in the Upper Colorado River Basin, and these areas are gradually converting to conifer forest by the natural process of ecological succession. This change is being hastened by forest managment practices that reduce fires, destroy pests, or otherwise prevent the natural processes that previously caused conifer areas to revert to the subclimax aspen. The hydrologic consequence has been forecast to cause a runoff reduction in the Colorado River as large as one million acre-feet annually, a major blow to water availability in the Lower Basin. Understanding and dealing with the problems requires quantitative comparision of the evaportranspiration rates of conifer and aspen forests under a variety of conditions. For this comparison, heat pulse velocity techniques were developed for monitoring water movement in aspen (Populus tremuloides), subalpine fir (Abies lasiocarpa), an Englemann spruce (Picea engelmannii). Once the techniques were perfected, transpiration was monitored in trees of each species for one year. The data were used to estimate crop coefficients by time of year for each species within the model ASPCON, a deterministic, lumped-parameter model describing the hydrology of aspen to conifer succession. The results for one location indicate a 7.3 in. net loss in streamflow when spruce replace aspen, and net loss of 2.8 in. when fir forests cover a watershed. Aspen began using significant amounts of water a month or two later in the spring and thus are associated with much higher spring runoff. While details vary greatly with location, the aspen to conifer successional trend is significantly reducing water yields within the Colorado River Basin.
From Source - Mendeley RIS export <br>
On - Tue May 10 12:12:47 CDT 2011
Additional Information
Identifiers
Type
Scheme
Key
Title
Citation
A Preliminary Quantification of the Impacts of Aspen to Conifer Succession on Water Yield Within the Colorado River Basin (A Process Aggravating the Salt Pollution …
