Threat Interactions

Interaction Function: noun
Date: 1832
def: mutual or reciprocal action or influence

It is becoming increasingly apparent that multiple, interacting disturbances combined with land use and climate change are affecting the structure and function of wildland ecosystems throughout the western United States. Although disturbance processes/regimes and reactions to environmental changes are integral to the function and evolution of ecosystems, the manifold effects are often socioeconomically undesirable, and thus are perceived as threats to society at large.

Major threat issues in the western wildlands include:

  • The frequency, extent, and severity of wildland fire have increased dramatically with correspondingly increased threats to human health and real property, and impacts on the functions and values of ecosystems.
  • Introduction and spread of exotic invasives and atypical expansion of native plants, animals, insects, and pathogens can significantly affect the integrity and function of forest, rangeland, and aquatic ecosystems, including viability of native species and habitats, and can threaten social and economic values of ecosystems.
  • Urban expansion and other forms of land use change comprise societally imposed ecological disturbances that together are significantly affecting the distribution, structure, function, and values of forests and rangelands. These impacts are expected to increase in the future in response to changing human demographics and needs.
  • Lastly, the realities of climate change have become recognized as a primary environmental concern of the 21st century. Yet knowledge of the potential impacts of climate change on ecosystems and resource-dependent publics is incomplete, and science-based options for coping with such impacts have received even less attention.

Currently WWETAC and cooperators are investigating several aspects of threat interactions in western wildlands. These include: