Effects

A large portion of the natural shrub-steppe has been converted into cropland for use in commercial agriculture. Much of the habitat has been lost, degraded, isolated, or fragmented. Less than half of the shrub-steppe habitat remains today. 

The highly fragmented landscape caused by the clearing of shrub-steppe communities for agriculture has been a cause of major ecological disturbance in the area. The most noticeable effect is the decrease of species richness and/or abundance in both plants and animals.

Shrub-steppe habitat then (top) and now (bottom)

Green=forest, Brown =shrub-steppe, 

Tan=cropland

The most well researched affect of shrub-steppe fragmentation is its effect on the sage-grouse species. The sage-grouse is a bird species found in the western United States as well as parts of Canada. They are obligate residence of ecosystems containing sagebrush. The shrub-steppe habitat provides everything they need for survival. The sage grouse’s diet consists of sagebrush, insects and other smaller plants, and they nest on the ground and use sagebrush as protection. They do not migrate or move long distances during its lifetime. Therefore, fragmentation is hurting the sage grouse population greatly because the species is a permanent resident of the shrub-steppe habitat in Washington. 

The sage grouse

Historic and recent declines of sage grouse are linked to conversion of native habitat for production of crops and degradation of the remaining native habitat. Some estimate that during the last one hundred years, the sage grouse population in the western United States went from 16 million to 200, 000. Data suggests that the sage grouse population in Washington State has been on a steady decline for the last 15-20 years. 

Although declines in populations of sage grouse in Washington State appear to be slowing, the small size and isolated nature of the population may be a long-term problem. Management should be directed toward protecting, enhancing, expanding, and connecting the existing populations.