1. Problem statementgrasslands in oklahoma have been shaped by the fine fuel-fire feedback for thousands of years before the european settlement

This $624,309 Cooperative Agreement awarded by the Department of the Interior's Bureau of Land Management under the Joint Fire Science Program (CFDA 15.232) will support Oklahoma State University in evaluating the long-term effectiveness of prescribed fires in reducing hazardous fuel accumulation and wildfire risks across Oklahoma's grasslands. The key products and services to be delivered include:

1. Determining post-prescribed fire vegetation growth and fuel accumulation rates at five long-term sites across different climate zones in Oklahoma.
2. Identifying the impacts of prescribed fires in mitigating potential wildfire behaviors statewide.
3. Projecting future changes in fuel accumulation and prescribed fire effectiveness under climate change at the state level.

The findings will provide science-based guidance to Oklahoma landowners and government agencies on optimizing prescribed fire strategies to adapt to evolving wildfire risks over the 21st century. Project outcomes are expected to improve prescribed fire effectiveness, mitigate extreme wildfire damages, and enhance grassland ecosystem services.

However, along with the aggressive fire exclusion and suppression policies in the 20TH century, the feedback between fine fuel and low-intensity fires has been disrupted, resulting in significant changes in fuel characteristics and more extreme wildfires. Over recent decades, the RE-introduction of fire into the grassland system has been recognized as an effective strategy to control woody plant encroachment and reduce heavy fuel accumulation. Multiple experimental sites have been set up in oklahoma to study prescribed fire impacts at the site level and more landowners have accepted prescribed fires as a regular management practice. However, the longevity of prescribed fire effectiveness to reduce hazardous fuel accumulation has not been understood at the state level across climate zones and under changing climate conditions. Without such information, the statewide application of prescribed fires to mitigate the risks of future extreme wildfires will be unlikely. Therefore, there is a critical need to have an improved knowledge of the longevity of prescribed fire effectiveness across climate zones and under climate change based on long-term field studies and modeling approaches.2. Objectivesour overall objective is to have a statewide evaluation of vegetation change and fuel accumulation over time after prescribed fires and determine the longevity of prescribed fire effectiveness in reducing the severity of potential wildfires under contemporary and future climate conditions. Our central hypothesis is that, due to the expected increases in extreme fire weather under future climate change, more frequent prescribed fires are needed to control fuel accumulation and reduce wildfire intensity. We propose three specific objectives: (1) determine post-treatment vegetation growth and fuel accumulation rates at five long-term prescribed fire grassland sites, located in different climate zones (2) identify the effect of prescribed fires in mitigating potential wildfire behaviors across oklahoma grasslands and (3) determine future changes in fuel accumulation rate and the longevity of prescribed fire effectiveness under climate change at the state level.3. Benefitsin the project, we will provide science-based, site-specific maps for oklahoma landowners to adjust prescribed fire strategies in five 20-year periods throughout the 21ST century. We will also provide critical information for government agencies to make long-term preparedness and prioritize fuel management resources to adapt to future changes in fuel accumulation and wildfire fire behaviors. Project outcomes will include (1) improvement in prescribed fire effectiveness across oklahoma grasslands, (2) mitigation of extreme wildfire risks and reduction in wildfire-caused damages and the costs of fighting wildfires, and (3) enhancement in grassland ecosystem services (such as improvement in forage production and wildlife habitat quality) using prescribed fires. The target audiences will include (1) land and fuel managers and prescribed fire planners in oklahoma (2) government agencies and tribal organizations for community wildfire protection and adaptation, wildlife conservation, and disaster response and (3) scientific researchers in fire ecology, wildlife ecology, and rangeland management. Project outcomes will be transferred to target audiences through workshops, field tours, scientific publications, and regional and national conferences related to land management and wildland fires.