Progress 09/01/22 to 08/31/23
Target Audience: Research community - we have presented our preliminary research plan and preliminary data at several workshops and conferences, engaging the broader research community to provide preliminary feedback to enable us to modify our plan to ensure we are appropriately addressing our research questions. We have also visited field sites with several expertsinthe research community to share research ideas and help us to modify our research plans. State forest managers and policy makers - we have engaged with several state forest managers and policy makers as we have finalized our research plan and begun to collect preliminary research data to ensure our data will provide useful knowledge. We have also been partnering with state land managers to leverage their current investments in post-fire research to enable a broader impact from our research. Forest industry - we have engaged with several members of the forest industry to investigate different approaches to post-fire land management so that we might compare how differential approaches impact soil health and vegetation recovery. Undergraduate students in natural resource sciences - we have employed several under-represented minority students to work on our project and gain valuable knowledge on the effects of wildfire and post-fire management on soil health. We have also shared our research results at local symposia that have enabled the undergraduate community to access this knowledge. Changes/Problems:In the original research plan we had indicated a desire to assess four post-fire land management strategies, including (a) burned and unmanaged (reference), (b) burned and salvage logged, (c) burned, salvage logged, and revegetated with planted seedlings, and (d) burned, salvage logged, and revegetated with aerial seeding. However, after detailed site visits it appeared as there was likely not enough comparable land area in the burned, salvage logged, and aerial seeding land type. As such, we have focused our efforts on the other three treatment types and increased our efforts in these areas to improve the likelihood of producing meaningful outputs that will provide insights into how the different post-fire management treatments impact soil hydraulic properties, soil nutrients, and vegetation recovery. What opportunities for training and professional development has the project provided? The PI developed and provided a directed readings and seminar course on "Post-fire soil physical and chemical properties" that support three graduate students that are affiliated with the project. This provided an opportunity to read and discuss key papers relevant to the proposed research. The PI has met weekly for one-on-one mentoring with each of three graduate students affiliated with this project to discuss the research design and explore preliminary data. This has provided critical training to these students in thinking about study design and limitations associated with some proposed research activities. The Forest Ecohydrology and Watershed Science (FEWS) Lab at Oregon State University hosted a full day workshop on field and laboratory methods in soil and hydrology research. This workshop was fully attended by three graduate students and four undergraduate students in our lab group, which enabled them to gain new knowledge and relevant skills for the upcoming field season. Graduate student and undergraduates were able to attend and participate in several valuable conferences and workshops over the past year, including (a) Oregon post-fire research and monitoring symposium, (b) 8th Interagency Conference on Research in our Watersheds, and (c) the American Geophysical Union Fall Meeting. How have the results been disseminated to communities of interest?Early results have beendisseminated to the various communities of interest through (a) presentation of our preliminary research plan and preliminary data at workshops and conferences, (b) on-line and in-person meetings to receive preliminary feedback on our research plan to enable us to modify our plan to ensure we are appropriately addressing our research questions, and (c) field site visits with expertsinthe research community to share research ideas and help us to modify our research plans. What do you plan to do during the next reporting period to accomplish the goals?To achieve our objectives, we will continue to collect soil samples from replicates of each of the post-fire land management treatments to quantify soil physical properties. Specifically, we will quantify soil particle size distribution, soil organic matter content, unsaturated hydraulic conductivity, and soil sorptivity. We will also quantify hydraulic conductivity measurements spatially across burned and unburned watersheds to develop spatial models that will enable us to relate the observed effects of wildfire and post-fire management. We will also install sensors in the field to quantify soil water content and matric potential to develop soil water retention curves for the various treatments. All soil physical and hydrologic property measurement locations will be co-located with vegetation survey quadrats and soil nutrient sites. We will also collect mineral soil from hillslope transects in unburned reference and burned and post-fire managed sites. Samples will be collected from two soil depths, 0-5 cm, and 5-10 cm, and used to quantify total carbon and nitrogen. We will also quantify ground cover and vegetation cover in each of our plots to relate back to our soil physical properties, soil water content, and soil nutrients.
What was accomplished under these goals?
Our study will provide critical foundational and applied knowledge that will improve our understanding of the compound effect of wildfires and forest management practices on soil physical properties, biogeochemical processes, and forest productivity. Our research will make it possible for spatially explicit, science based post-fire management strategies that will facilitate more rapid recovery of soil health and forest productivity on state, federal, and industrial forest lands. To achieve the objectives of our study, we downloaded and organized spatial data layers of recent burn perimeters, burn severity, digital elevation models, soils, geology, vegetation, and land ownership across western Oregon. We then analyzed these data layers to identify potential research sites, controlling for differences in site characteristics. We then coordinated with various land owners (federal, state, and industrial) to identify different post-fire land management practices that were used across potential comparison sites. We completed field reconnaissance to field validate our spatial analysis and established potential research sites. From these sites we have begun collecting preliminary data on soil infiltration capacity, saturated hydraulic conductivity, and soil water content. We have been collecting this data at a high spatial resolution, which will enable us to relate point measurements to our spatial data to develop spatially predictive models if we can relate our measurements back to specific site locations. We have also begun collecting soil samples from the upper 0-5 cm and 5-10 cm and have been processing this samples in the laboratory to quantify soil texture, bulk density, gravimetric water content, and carbon and nitrogen concentrations. We have also been working with land owner to quantify vegetation species, density, and growth rates. We have also begun exploring methods to extract the water from soil samples, which will enable a deeper assessment of wildfire effects on dissolved organic matter character through excitation-emission matrices (EEMs) analysis. As we are in the first year of our study, we do not yet have summary statistics to share. We look forward to being able to share this data in the following year.