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Columbia Plateau Human Impact

The Columbia Plateau faces a complex set of challenging conservation issues. These include:

  • Agricultural Conversion. More than half of the shrub-steppe and 70% of the grasslands have been converted to agriculture, from dryland wheat fields to vineyards. This has reduced or fragmented riparian forests, shrub-steppe, and grasslands, resulting in habitat loss for imperiled species such as sage and sharp-tailed grouse, American badgers, and pygmy rabbits.
  • Housing Developments. Conversion of agricultural or undeveloped lands to residential use is another pressing issue. Subdivisions and ranchettes, particularly near riparian areas, threaten critical habitat by dislocating wildlife and blocking migration corridors.
  • Hydropower Impacts. Dams on the Columbia and Snake Rivers submerged floodplain and riparian habitats. Dams also pose significant difficulties to fish such as salmon, sturgeon, and lampreys. Sedimentation, pesticides, and dewatering further complicate fish passage and riverine processes.
  • Changes in Fire Regimes. Changes in the natural fire regime have degraded plant communities in the Columbia Plateau ecoregion. More frequent fires, often fueled by cheatgrass and other alterations to shrub-steppe ecology, have eliminated some sagebrush communities. Fire suppression has encouraged encroachment of shrubs and trees on native Palouse grasslands.
  • Environmental Pollutants. The Columbia Plateau faces contamination from pesticides, herbicides, and other agricultural chemicals; industrial effluents from pulp mills and aluminum plants; and radioactive wastes from the Hanford Reserve.
  • Non-native and Invasive Species. Brook trout and bullfrogs are among the invasive animal species jeopardizing the Columbia’s Plateau’s biological heritage. Noxious weeds, from cheatgrass to knapweed to Russian olive, displace or alter the functioning of native plant communities.
  • Energy Development. Transmission lines and wind turbines can threaten bird habitats and flyways in the region, home to a great number of raptors. Oil and gas development pose additional concerns.

For many, the Columbia Plateau’s biological richness makes it one of the state’s highest conservation priorities. In recent years, a wide range of partnerships among state and federal agencies, universities, and nonprofit organizations have emerged to tackle the ecoregion’s challenges. Ongoing programs work to inventory and monitor priority species; enlarge natural areas; and implement weed control and conservation planning.

Also underway are projects to encourage rural vitality and environmental stewardship. One such effort is the Healthy Lands Initiative, funded in part by the Washington Biodiversity Council.


For details of this ecoregion within Washington, click a subheading in the left column.

View the more general description of this ecoregion in North America

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