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The Cheadle Center at UCSB manages more than 340 acres of open space between Ellwood Mesa and Goleta Slough, carrying out ecological restoration, research, and education projects at these sites. Characterized by a rich complex of oak woodland, coastal sage scrub, grassland, and wetland ecosystems, the area is known for its relatively high level of biodiversity. The Cheadle Center’s project sites and management areas serve to protect and strengthen the region’s ecology and ecosystems through habitat conservation, upland restoration, wetland creation and enhancement, and the implementation of sustainable stormwater management solutions. Through careful integration with local watersheds and surrounding natural areas,The Cheadle Center's management areas provide an important corridor and refuge for wildlife, ensure the long term preservation of the region's natural resources, and serve as outdoor classrooms, research sites, and recreational areas for the campus community and the public.This archived version of the May 2023 newsletter includes updates on a screening of the documentary Bringing Back Our Wetland and water level and salinity fluctuations in Devereux Slough. The feature story focuses on controlled burning and wildflower seeding on Lagoon Island to convert nonnative grassland to native coastal sage scrub. Community photos include red fox (Vulpes vulpes), reddish egret (Egretta rufescens), cattle egret (Bubulcus ibis), ash-throated flycatcher (Myiarchus cinerascens), desert cottontail (Sylvilagus audubonii), and great horned owl (Bubo virginianus).&nbsp

The issue of damaging wildfires has been thrown into the public consciousness as wildfires have grown tremendously in recent years. The 2021 California Dixie fire burned 963,309 acres over the course of 3 months and became the second largest wildfire by acreage in California. As wildfires become an increasingly prominent issue, it is imperative to ensure the effectiveness of current policies and technologies regarding wildfires. Both of my projects focused on wildfire management. For the technical project, my UVA Aircraft Design Capstone team made a conceptual design of a responsive aerial firefighting aircraft for submission to the AIAA 2022 Design Competition. My STS research focused on the effects of past and current U.S. wildfire policy. This topic was chosen to closely relate to my technical project because firefighting aircraft will only be as effective as the wildfire policies they enforce. To understand the effectiveness of these aircraft, it is necessary to study the greater picture of U.S. wildfire policy as a whole. My Capstone group, Team Splashzone, analyzed the AIAA request for proposal (RFP) requirements and objectives for a responsive aerial firefighting aircraft. A key objective we focused on was a fire retardant capacity of 8,000 gallons. With this objective chosen, we selected a design mission that includes three 2,000 gallon retardant drops. As 8,000 gallons (72,000 lbs) of retardant greatly increased the maximum takeoff weight of our aircraft, we set a goal to minimize aircraft size and weight while maintaining stability and structural integrity. From the preliminary design to critical design, we reduced our aircraft length from 160 ft to 83.5 ft and take-off gross weight (TOGW) from 273,386 lbs to 181,806 lbs. These changes greatly contributed to significant cost reductions for our aircraft. These large weight and size reductions were made possible by wing and tail trade studies, optimized tail volume coefficients, aerodynamic and structural analysis, cost analysis, and optimized tank design. A key contributor to maintained aircraft stability throughout the mission is the placement of key changing weights (e.g., changes in weight from payload drops or use of fuel). The aircraft maintains its center of gravity (CG) throughout the design mission by centering the payload about the CG and placing fuel in the wing which is close to CG. While firefighting aircraft are a key portion of wildfire management, they are only effective as long as wildfire policy is. In my STS research I investigated the research question “What are the impacts of past and current U.S. wildfire policy?” using the STS methods of history through literature study, public policy through research on current and future wildfire policy, and ethnography through the gathering of interviews of key groups of interest such as Indigenous fire stewards. My research finds how the U.S. fire regime shifted greatly from millennia of natural wildfires and Indigenous fire stewardship to fire exclusion and active suppression. The 100 years of these policies had many negative effects, with some of the greatest being the marginalization of Indigenous peoples and the buildup of plant material which in turn helped spawn damaging wildfires called high-impact mega-fires. Current policy has made some progress to right these wrongs, and new policies are in the works to further impact the U.S. fire regime. Based on my research I make informed recommendations such as strengthening Indigenous peoples’ right to conduct controlled burns, expanding programs which bring together a diverse set of perspectives to wildfire management, and choosing more comprehensive fire management strategies over greater suppression force. By executing STS research in addition to my technical project, I was able to greater understand the bigger picture of U.S. wildfire management that my technical work contributes to. Both projects combined reveal the fine line wildfire policy and procedure must tread between suppressing and using fire to minimize costly damages that high-impact mega-fires pose while maximizing the benefits fire can bring. I would like to give special thanks to my technical advisor, Jesse Quinlan, STS advisor, Joshua Earle, and my Capstone Team Splashzone members: Hayley Knowles (Team Lead), Spencer Barnes, James Graham, Kevin Moccia, Joseph Orrico, Kobi Vance, Brendan Whalen, and Jackson Wray. I would not have been able to conduct this work without their support!

After nearly two centuries of logging, only a small percentage of original old-growth forests in the Pacific Northwest (PNW) remains. Old-growth forests are characterized by heterogeneous forest structures with large and mature trees, multi-story canopies, and complex understories composed of snags, logs, and downed woody material. To jumpstart succession processes and restore old-growth forests, structural complexity enhancements (SCE), including prescribed burning and variable-density thinning, have been developed and used more frequently in forest management. Compared to traditional thinning methods (thin from below), SCE have been documented to provide greater ecosystem-wide benefits (Harmon et al. 1990, Gunn et al. 2014). To test the effectiveness of SCE techniques in the PNW, the long-term effects of different management methods—prescribed burning, variable-density thinning, and traditional thinning—on previously logged coastal forests of the South Slough National Estuarine Research Reserve (NERR) located in Charleston, Oregon were investigated. Using the Forest Vegetation Simulator (FVS), 11 forest stands of different age classes were simulated from 2015-2125 under four management scenarios: no action (control), traditional thin from below, variable-density thin, and prescribed burn. The main variables of interest were structural complexity and carbon sequestration. Forest structure complexity (large trees, large snags, downed wood) was quantified using the Old Growth Habitat Index. Results showed that there were no significant differences in carbon sequestration among treatments except for the control. Thinning and variable-density thinning were similar across all structural elements and were most effective at accelerating large tree growth. The control treatment created the most downed wood and large snags. Among treatments excluding the control, prescribed burns created the most snags and downed wood. Findings suggest that multiple variable-density thin treatments or a combination of treatments may need to be implemented in order to effectively promote structural complexity.

Low-intensity burnings could be an effective silvicultural tool to prevent the occurrence and severity of wildfires. Nevertheless, their use as a forest fuel reduction tool may have a negative impact on soil properties. The aim of this investigation was to study the impact of a low-intensity prescribed fire on the main chemical properties of the soil (pH, electrical conductivity, and total organic carbon), and the diversity and composition of the soil bacterial communities in a semi-arid forest in SE Spain. Two similar stands were treated with a low-intensity prescribed burn in spring and autumn 2018 and were compared to an unburned stand. All soil samples were collected at the same time (autumn 2018). The chemical properties of the soil showed no significant differences between the prescribed burns and the control forest. Shannon and Pielou’s diversity indices presented values significantly lower in the burned soils compared to the control. Prescribed burning did not modify soil bacterial community structure at the phylum level, but NMDS analysis did reveal a difference between soil bacterial communities at the genus level. Both prescribed burnings favoured some bacterial taxa over others, suggesting different thermal and bacterial resistance. The presence of Massilia, Pseudomonas and Arthrobacter could suggest a short-term ecosystem recovery. Therefore, prescribed burning in semi-arid forests could be suitable as a preventive tool against wildfires.

Litter from pine trees in open woodlands is an important fuel for surface fires, but litter from hardwood species may quell fire behavior. Lower intensity fires favor hardwood over longleaf pine regeneration, and while overstory hardwoods are important sources of food and shelter for many wildlife species, too many could result in canopy closure and a loss of ground layer diversity. Although some researchers have found synergies in fire effects when leaves of different species are combined, field tests of effects of tree guild diversity on fire behavior are lacking from the literature. We used neighborhood modeling to understand how diverse overstory trees in longleaf pine forests affect fire radiative energy density (FRED), and to determine the effect on top-kill of shrub-form hardwood trees. We measured the effects of three guilds of overstory trees (longleaf pine, upland oaks, and mesic oaks) on FRED, and related FRED to post-fire damage in four guilds of understory hardwoods (sandhill oaks, upland oaks, mesic oaks, and fleshy-fruited hardwoods). We found that FRED increased 33–56% near overstory longleaf pine but decreased 23–37% near overstory mesic oaks. Additive models of FRED performed well and no synergies or antagonisms were present. Seventy percent of stems of understory hardwoods survived fire with energy release typical of dormant-season fires in canopy gaps and near overstory mesic oaks. We also found that among understory trees >2 m tall, upland and sandhill oaks were more likely than mesic oaks or fleshy-fruited hardwoods to avoid top-kill. We conclude that neighborhood models provide a method to predict longleaf pine forest structure and composition that allows for the ecological benefits of overstory hardwoods while maintaining ground-layer diversity. To maintain hardwood control, fire practitioners may need to select fire weather conditions to increase fire behavior especially during dormant-season burns.

We investigate the spatiotemporal patterns of prescribed fire and wildfire within Washington State, USA using records from the state’s Department of Natural Resources (DNR). Spatiotemporal comparisons of prescribed fire and wildfire area burned revealed that (1) fire activity broadly differed between the eastern and western portion of the state in terms of total area and distribution of burn sources, (2) over the 2004–2019 period, wildfire largely replaced prescribed fire as the predominant source of burning, and (3) wildfire and prescribed fire occur during distinct months of the year. Spatiotemporal variation in prescribed fire activity at regional levels were measured using five parameters: total area burned, total biomass burned, burn days, burn approval rates, and pile burn frequency. Within-region spatial variability in prescribed fire parameters across land ownership categories and bioclimatic categories were often detectable. Regression models of the annualized prescribed fire parameters suggested that prescribed fire activities have been declining in multiple administrative regions over the 2004–2019 period. A descriptive analysis of seasonal trends found that prescribed fire use largely peaked in the fall months, with minor peaks usually occurring in the spring. Lastly, we described how area burned, biomass burned, and pile burn frequency differed between prescribed fires approved and denied by the DNR, and found that approved prescribed fires were typically smaller and burned less biomass than denied fires.

Over the past century, scientific understanding of prescribed burns in California’s forests transitioned from being interpreted as ecologically harmful to highly beneficial. The state’s prescribed burn policies mirrored this evolution. Harold Biswell, a University of California at Berkeley ecologist, studied prescribed burns and became a major advocate for their use during the 1950s and 1960s. Drawing primarily on archival materials from Biswell and the state government, this historical case study presents an example of how a scientist successfully contributed to integrating research into policy and practice through consistent and targeted science communication to gain allies among environmental organizations, local stakeholders, and governments. Though at first isolated by his academic peers for proposing that fire could provide environmental benefits in forests, Biswell continued conducting and sharing his research and findings with academic and non-academic audiences. Over several decades, Biswell engaged in conversations which ultimately advanced policy changes at the state level to expand the use of prescribed burns. Despite lacking a formal role in government, Biswell used his academic platform to promote the policy implications of his research. Current and future researchers can draw on these lessons to advocate effectively for other science-informed policies.

Background While the effects of prescribed burning on tree regeneration and on pyrophilous and/or saproxylic species are relatively well known, effects on other organisms are less clear. The primary aim of this systematic review was to clarify how biodiversity is affected by prescribed burning in temperate and boreal forests, and whether burning may be useful as a means of conserving or restoring biodiversity, beyond that of pyrophilous and saproxylic species. Methods The review examined primary field studies of the effects of prescribed burning on biodiversity in boreal and temperate forests in protected areas or under commercial management. Non-intervention or alternate levels of intervention were comparators. Relevant outcomes were species richness and diversity, excluding that of pyrophilous and saproxylic species. Relevant studies were extracted from a recent systematic map of the evidence on biodiversity impacts of active management in forests set aside for conservation or restoration. Additional searches and a search update were undertaken using a strategy targeted to identify studies focused on prescribed burning interventions. Grey literature and bibliographies of relevant published reviews were also searched for evidence. Studies were assessed for internal and external validity and data were extracted, using validity assessment and data extraction tools specifically designed for this review. Studies were presented in a narrative synthesis and interactive map, and those which were suitable were quantitatively synthesised using meta-analyses, subgroup analysis and meta-regression. Results Searches generated a total of 12,971 unique records. After screening for relevance, 244 studies (from 235 articles) were included in this review. Most studied forests were located in the USA (172/244), with the rest located in Canada, Europe and Australia. Eighty-two studies reporting 219 comparisons were included in the quantitative synthesis. Within the meta-analyses for each group of taxa, we identified a small to moderate volume of evidence, and heterogeneity was ubiquitous. Prescribed burning had significant positive effects on vascular plant richness, non-native vascular plant richness, and in broadleaf forests, herbaceous plant richness. Time since the burn, forest type and climate zone were significant moderators predicting the effect of burning on herbaceous plant richness. No other significant relationships were identified. Conclusions Knowledge gaps exist for studies outside North America, in mixed forests and for non-plant organism outcomes. We identify a need to apply study designs consistently and appropriately, minimising the impact of confounding factors wherever possible, and to provide extensive detail in study reports. We recommend that researchers build long-term datasets charting the impacts of prescribed burning on succession. The lack of consistent findings was likely due to high inter-study heterogeneity, and low numbers of comparable studies in each quantitative synthesis. We found no consistent effects of moderators, and were unable to test the effect of many potential moderators, due to a lack of reporting. Rather than making any general recommendations on the use of prescribed burning for biodiversity restoration, we provide an evidence atlas of previous studies for researchers and practitioners to use. We observe that outcomes are still difficult to predict, and any restoration project should include a component of monitoring to build a stronger evidence base for recommendations and guidelines on how to best achieve conservation targets. Prescribed burning may have harmful effects on taxa that are conservation-dependent and careful planning is needed.

Grass management has been used for many years at airports in an attempt to reduce numbers of birds and other wildlife and the collisions with aircraft associated with them. We evaluated the impacts of grassland alteration by mowing and fi re on the abundance, diversity, and frequency of birds using 1 control and 2 experimental grass plots from 2009 to 2010 on a U.S. Army airfield in Colorado located in short-grass prairie. Density of breeding birds was highest in the mowed plot. Numbers of birds observed in 34 surveys conducted during the non-breeding season in the burned (x = 41) and mowed (x = 24) plots were greater than in an unmanaged control (x = 7) plot. Bird species diversity in the nonbreeding season was greatest in the control plot. Horned larks (Eremophila alpestris) was the most frequently observed bird species and occurred in high numbers on the burned and mowed plots, possibly because of its preference for short vegetation and bare ground. This species is recognized as hazardous to aircraft in part because of its habit of forming large flocks in the nonbreeding season. All 3 study plots were dominated by grasses and forbs, with minimal shrub and cactus cover. Litter cover was greatest on the control plot, while the burned plot had the greatest coverage of bare ground. Results from this study are limited because the small size of the airfield precluded placement of multiple treatment plots. Additional study in larger airfields with multiple treatment plots would be required before management recommendations regarding the use of fi re and mowing can be made for airfields in areas with short-grass prairie.