Effects of short-interval wildfires on interactions among plants, soils, and microbes in Pacific Northwest conifer forests

Decades of fuel accumulation and increasing aridity are causing more frequent wildfire in many western forests. Frequent fire often reduces soil fertility in forest types with low precipitation. However, it is unclear whether this is also the case for more productive, wetter forest types, like those found in the western Cascade Mountains of the Pacific Northwest, where fire has been less frequent historically. This goal of this research is to evaluate interactions among regenerating vegetation, soil fertility and microbial communities after single high severity fires and short-interval reburns. Ultimately the scientific knowledge gained from this project will help predict the time scale and the trajectories of soil recovery after wildfires in coniferous forests with high precipitation. The research team engages with land managers to understand how to improve post-fire forest regeneration and restoration in the region. This project also collaborates with Outdoor School educators resulting in hands-on and field-based activities to increase the wildfire and scientific literacy of students. The overarching goal of this research is to characterize the patterns and timescale of soil recovery after fire. The key is understanding the complicated mechanisms underlying the interactions among plants, soils, and microbes after high-severity fires. The project uses a combination of field sampling, field manipulations and laboratory experiments to test the central hypotheses about these mechanisms. Initial surveys of vegetation and soil properties establish baseline patterns, and sites that have burned at different times provide a picture of soil recovery. Complementary mechanistic work characterizes contributions of photodegradation to litter decomposition, and disentangles the effects of microbial communities and soil properties. Once the framework is developed to assess wildfire impacts, the future trajectory of these forests can be better understood. Further, there are direct links to help prioritize forest rehabilitation and restoration efforts in coniferous forests with high precipitation. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. NSF Award ID: 2533361 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Georgia Seyfried | Institution: Oregon State University, CORVALLIS, OR | Award Amount: $709,775 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2533361 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2533361.html