Page 34

Working Ranch April/May 2016

too, because there are fewer insects to provide food for fi sh. Even livestock won’t do as well in areas with tamarisk because it’s not as palatable as other forage.” In water recreation areas, tamarisk’s dense thickets make it nearly impossible for boaters and hikers to travel in areas where it grows. Its habit of accumulating in dry, woody stands also raises wildfi re risks. Landowners in Grand Junction, CO, became so concerned about tamarisk invasion some 15 years ago that they formed the Tamarisk Coalition to launch an effort to manage tamarisk in their area. While they haven’t eliminated the species, they have signifi cantly reduced its dominance in riparian areas in their region and helped educate other landowners and the public about tamarisk threats and management. The Coalition’s mission is to establish “healthy and self-sustaining riparian ecosystems throughout the American West resilient to invasive plant species and supported by enduring communities of stewards.” More information about their activities and resources is available at www.tamariskcoalition. org. “Tamarisk is just one of the invasive species threatening riparian areas,” Thompson says. “Russian olive also tends to outcompete native trees in riparian areas, reducing the habitat for birds and insects. The fi rst line of defense for invading species is to fi nd them when there are only a few plants. The easiest way to control undesirable plants is by removing them before they have a chance to become established.” ANNUAL CHECKUP Evaluating riparian areas on an annual basis is the most effective way to identify any existing or potential problems. Thompson and the Bureau of Land Management work with teams of specialists from numerous backgrounds to evaluate the functioning condition of riparian areas. A typical assessment evaluates stream hydrology, vegetation species and diversity as well as erosion and deposition rates. “When a riparian area is functioning properly, energy dissipating characteristics of the riparian area help keep fl ood events from causing the stream channel to become overly wide or deep,” Thompson shares. “If the channel downcuts 10 to 15 feet deep, riparian plants that draw water from the water table lose contact with that moisture and begin to die out. As that happens, the function of the riparian area declines quickly.” The primary benefi t of maintaining the best-possible function of riparian areas is to ensure dissipation of high fl ow events that can cause erosion and damage to soil and vegetation. Highly functioning riparian areas are pasture management JAY THOMPSON Students in a riparian condition assessment class take measurements on the Crystal River near Carbondale, Colorado. 34 I WORKING RANCH I APRIL / MAY 2016


Working Ranch April/May 2016
To see the actual publication please follow the link above