Fire and Wildlife Ecology
Fire and Wildlife Ecology Intersect: Gila National Forest
Gila National Forest, Southwestern New Mexico
Wildland fire ecology is such a dynamic field partly because it touches so many aspects of natural resource science and management. No one knows this better than Professor Penelope Morgan and Zachary Holden, biological scientist with the USDA Forest Service (University of Idaho graduate).
Wildland Fire Concepts Take Hold
In 1975 the US Forest Service initiated a policy, now known as Wildland Fire Use, which is a concept that allows lightning-ignited wildfire to burn without intervention, or with minimal management and containment, with the long-term goal of reducing fuel loads and eventually returning the forest to a regime of smaller, less severe fires. According to Professor Morgan Gila National Forest was one of the first areas to embrace this fire methodology.
Juggling Natural Resource Priorities
This area, ripe for highly severe fires, can also have a damaging effect on wildlife and fish. Responding on a fire-by-fire basis to threats to fishery ecosystem is challenging and also places and added stress on natural resource professionals. For example, mangers must balance sometimes conflicting mandates, such as protecting endangered species, like Gila trout and chub, while continuing the progressive use of Wildand Fire Use for the benefits it provides natural forest ecosystems (enhancing the soil with nitrogen, forest regeneration, etc.)
Assessing Fire Severity
After a series of severe fires, natural resource managers in the Gila National Forest were keenly aware of the need for better information and predictive models to examine the effects of the effects of fire on fish to assist in management decisions. As part of his graduate research work at the University of Idaho, Holden studied satellite images, collected over a 20-year period, to determine the ecological effects of fires in the Gila Forest and to produce a burn severity atlas. This burn severity data would then allow land managers to better respond and protect endangered fish.
Resource Management Take Away’s:
- Managers need timely, current information to plan for fire season and to assess the results of management decisions after fire season, particularly when balancing the overall needs of our land, including forests and wildlife and fish habitats
- Natural resource specialists and fire ecologists and managers must collaborate before fire season to properly plan
- Remote sensing data combined with field data is most valuable because it lets ecologists study the magnitude of post-fire ecological effects on soil characteristics, hydrology and tree mortality. Researchers also believe annual satellite data is needed to properly monitor and determine if a wildland fire is meeting its objectives (enriching the soil and regenerating the forest), if left to burn.
The results suggest that the best strategy to benefit the Gila trout is to expand the size of existing habitat patches in the Gila River and Mogollon Creek drainages. The tributaries that support fish in these two waterways provide increased connectivity, allowing the fish to migrate and seek refuge in case of fire.
Historical burn severity information may help resource managers to plan for actions before and during fire seasons to ensure the long-term survival of the Gila trout and Gila chub. In addition, predicting the likelihood and location of severe fires and potential debris and ash flows can guide decisions about which streams are best suited to support fish populations for the long term.