Proliferation of non-native invasive plants in the Southwest influences fire regimes. Changes in fire regime attributes such as increased fire frequency, higher severity, and greater extent often result in degraded ecological conditions and can pose increasing threats to human infrastructure and lives. The southwestern United States is home to large strategic military installations, including the Army’s Fort Irwin National Training Center, Edwards Air Force Base, the Naval Air Weapons Station China Lake, the Marine Corps Air Ground Combat Center, and Nellis Air Force Base. Management strategies for these installations must balance maintenance of ecosystem function and protection of important species habitats with the need to sustain military testing and training. Fire frequency may increase in these ecosystems as climate changes and non-native plants continue to invade and increase in abundance. Better information and improved models are needed to describe the regional effects of increasing dominance of non-native invasive plants and to understand how the growth and dynamics of invasive annual grasses affect the fire regimes in hot desert, shrubland, and woodland ecosystems of the southwestern United States. 

The overall objective of this project is to build upon and integrate recent advances in foundational fire science and remote sensing to produce decision-support documents and tools that DoD and other land managers can use to more effectively and efficiently manage non-native invasive plant species and wildfire in the Mojave bioregion now and under changing climate conditions. Specific objectives include the following: (1) develop post-fire successional models; (2) develop current fire regime models and evaluate potential future fire regimes with respect to climate change; (3) develop habitat models and create maps for the non-native invasive plants associated with altered fire regimes (i.e., annual grasses); (4) develop current non-native invasive plant detection and fire hazard assessment tools and create current maps of their distributions; (5) develop a burn severity evaluation tool; (6) produce a fire management handbook and conduct training workshops for land managers; and (7) create a fire management website for the Mojave bioregion.

This collaborative project will exploit the results and technical approaches of recent and ongoing studies by U.S. Geological Survey and Pacific Northwest National Laboratory research scientists to quantify the current and potential extent of non-native invasive annual grasses in the Mojave bioregion in relation to historic, contemporary, and future fire regimes under changing climate. Extensive field data sets documenting the presence, abundance, and growth stages of invasive annual grasses will be used with moderate and coarse-scale satellite remote sensing data to develop and improve models predicting the distribution of invasive species, burn severity, post-fire recovery, and potential ranges of invasive annual grass species.

In support of the management and recovery of ecological systems in the southwestern United States, this project will provide new information and tools to enable land managers to assess the direction and magnitude of landscape changes caused by fires, proliferation of non-native invasive grasses and future climate change. Products from this project will enable DoD installations in the Mojave bioregion to assess and plan for mitigation of hazard potential from fire under contemporary and future climatic conditions. (Anticipated Project Completion - 2014)