Death of an Ecosystem: The Sagebrush Steppe
For decades the sagebrush steppe ecosystem that covers approximately 206,000 km2 in the western USA has been the neglected stepchild of the environmental movement, of scientific research, and of conscientious land managers. However, dramatic changes have occurred in this ecosystem since European settlement in the mid 1800's. Overgrazing by livestock and feral equids, fragmentation, invasive weeds, and changed fire regimes have been devastating. A number of sagebrush-dependent species are in apparent decline, and two have been proposed for listing under the US Endangered Species Act. Now, as climate change interacts with defoliating insects, wildfire, and invasive annual grasses, projections suggest that 72% of the remaining sagebrush steppe vegetation could disappear within the next 50 years. Its replacement will be annual grasslands that support almost no wildlife and very limited livestock grazing. This represents an ecological and economic disaster of substantial proportions. However, aggressive post-fire revegetation and fuels management programs can slow down the loss of native vegetation effectively and result in lower long-term costs than current approaches. The trick is to design restoration and fuels management programs that do not destroy key habitat for certain sagebrush obligate species.