Invasive Species

View article.

In the more open Pinus ponderosa and Pseudotsuga menziesii forests, cheatgrass colonization may often occur in openings in the understory alone. Colonization in the more shady A. grandis and Thuja plicata forests is unlikely, however, unless the opening extends through both the understory and the overstory. As a result, cheatgrass is unlikely to increase in any of these forests unless the scale and incidence of disturbance increases substantially.

View paper.

This paper provides a historical perspective of the influence of cheatgrass invasion on western rangelands (1930-1950). This was a period of awakening interest by range scientists. Range managers, the livestock industry, and scientists have always bad a love-bate relationship with cheatgrass. It provides the bulk of the forage on many ranges, yet it is the symbol of environmental degradation. Trying to cope with the endless ramifications of cheatgrass invasion, dominance, persistence, and potential community decline keep forcing scientists to critically evaluate the ecological principles upon which range management is based.

View chapter.

The range livestock industry has adapted to the presence of invasive annual grasses, especially where infestations are extensive. Light to moderate livestock grazing provides enough standing grass at the end of the grazing season to limit soil erosion and conserve soil moisture and nutrients. Elsewhere, however, where infestations of invasive annual grasses are less extensive or less advanced, opportunities exist for using targeted, or prescribed, livestock grazing to suppress annual grass plants. This chapter focuses on using prescribed livestock grazing to suppress invasive annual grasses on sites where these grasses are considered weedy invaders.

View article.

Let us examine each of C. E. Fleming’s contentions concerning the status of cheatgrass as a forage species in light of what has happened during the last half of the 20th century to Nevada rangelands. Hindsight is a wonderful procedure that allows one to be pretentious, so we evaluate the Fleming contentions in terms of their foresight.

View paper.

Although this study helped pinpoint optimal defoliation parameters for cheatgrass control, it also called into question the potential for livestock grazing to be an effective seed-bed preparation technique in native plant reseeding projects in cheatgrass-dominated areas.

View article.

Cattle removed 80 to 90% of standing biomass in grazed plots in May of 2005 and 2006 when B. tectorum was in the boot (phenological) stage. Grazed and ungrazed plots were burned in October 2005 and 2006. The combined grazing–burning treatment was more effective than either treatment alone in reducing B. tectorum seed input and seed bank density, and in shifting species composition from a community dominated by B. tectorum to one composed of a suite of species, with B. tectorum as a component rather than a dominant. This study provides a meso-scale precursor for landscape-scale adaptive management using grazing and burning methodologies.