Jan L. Beyers

Wildland fire in ecosystems: effects of fire on soils and water

This state-of-knowledge review about the effects of fire on soils and water can assist land and fire managers with information on the physical, chemical, and biological effects of fire needed to successfully conduct ecosystem management, and effectively inform others about the role and impacts of wildland fire. Chapter topics include the soil resource, soil physical properties and fire, soil chemistry effects, soil biology responses, the hydrologic cycle and water resources, water quality, aquatic biology, fire effects on wetland and riparian systems, fire effects models, and watershed rehabilitation.

Fuel Breaks Affect Nonnative Species Abundance In Californian Plant Communities

We evaluated the abundance of nonnative plants on fuel breaks and in adjacent untreated areas to determine if fuel treatments promote the invasion of nonnative plant species. Understanding the relationship between fuel treatments and nonnative plants is becoming increasingly important as federal and state agencies are currently implementing large fuel treatment programs throughout the United States to reduce the threat of wildland fire. Our study included 24 fuel breaks located across the State of California. We found that nonnative plant abundance was over 200% higher on fuel breaks than in adjacent wildland areas. Relative nonnative cover was greater on fuel breaks constructed by bulldozers (28%) than on fuel breaks constructed by other methods (7%). Canopy cover, litter cover, and duff depth also were significantly lower on fuel breaks constructed by bulldozers, and these fuel breaks had significantly more exposed bare ground than other types of fuel breaks. There was a significant decline in relative nonnative cover with increasing distance from the fuel break, particularly in areas that had experienced more numerous fires during the past 50 years, and in areas that had been grazed. These data suggest that fuel breaks could provide establishment sites for nonnative plants, and that nonnatives may invade surrounding areas, especially after disturbances such as fire or grazing. Fuel break construction and maintenance methods that leave some overstory canopy and minimize exposure of bare ground may be less likely to promote nonnative plants.

The role of fire severity, distance from fire perimeter and vegetation on post-fire recovery of small-mammal communities in chaparral

Chaparral shrublands in southern California, US, exhibit significant biodiversity but are prone to large, intensewildfires.Debateexistsregardingfuelreductiontopreventsuchfiresinwildlandareas,buttheeffectsofthesefires on fauna are not well understood. We studied whether fire severity and distance from unburned fire perimeter influenced recovery of the small-mammal community from 13 to 39 months after the large (1134.2km 2 ) Cedar fire in San Diego County. In general, neither factor influenced small-mammal recovery. However, vegetation characteristics, distance to riparian habitat and the prevalence of rocky substrate affected recovery in species-specific patterns. This indicates the effects of fire severity and immigration from outside the fire perimeter, if they occur, do so within 1 year, whereas longer- term recovery is largely driven by previously known relationships between small mammals and habitat structure. Our results,whencombinedwithresultsfromother studiesinsouthernCalifornia,suggestwherehumanlivesor infrastructure arenotatrisk,effortstopreservechaparralbiodiversityshouldfocusonmaintainingthenativeplantcommunity.Doingso mayrequirenovelmanagementstrategiesinthefaceofanincreasinghumanpopulation,ignitionsourcesandthespreadof invasive exotic plants. Additional keywords: coastal sage scrub, fire management, shrubland. Received 26 May 2010, accepted 12 July 2011, published online 20 February 2012

Effects of hydromulch on post-fire erosion and plant recovery in chaparral shrublands of southern California

Following the Cedar Fire (one of seven large wildfires that burned in southern California during the autumn of 2003), aerial hydromulch was applied at 50 and 100% cover to reduce hillslope erosion in chaparral shrublands. Our objectives were to determine the effectiveness of hydromulch in preventing erosion, and to see if plant recovery was hindered by treatment. We installed 54 silt fences to measure sediment production. Five 1-m2 grids were placed behind each fence to measure plant recovery. Hydromulch was effective in reducing erosion immediately after the fire; however, its benefits appeared to be limited to the first 2–4 months following fire, raising doubts as to its overall cost-effectiveness. The rapid breakdown of the hydromulch during the first 6 months after the wildfire provided little hillslope protection during the above-average October 2004 storm events. During the October events, both rainfall amount and storm intensity played a role in the magnitude of sediment production. Hydromulch did not affect post-fire plant recovery, with plant cover measuring >60% at all sites less than 2 years following the wildfire. Accelerated growth of chamise and forbs was likely due to hydromulch prolonging soil moisture retention. Large accumulations of dead litter following die-off of the herbaceous species could increase dry fuels, thus promoting wildfire and therefore shortening the fire return interval.

Recent trends in post-wildfire seeding in western US forests: costs and seed mixes

Broadcast seeding is one of the most commonly used post-fire rehabilitation treatments to establish ground cover for erosion control and mitigation of non-native plant species invasions. Little quantitative information is available on overall trends of post-fire seeding expenditures and seed mixes used over time in forested ecosystems in the western USA. We reviewed scientific articles, government publications and unpublished documents as well as USDA Forest Service Burned Area Reports to determine trends in post-fire seeding in forested ecosystems over time. Of 1164 USDA Forest Service Burned Area Reports, 380 contained information on seeding treatments conducted in forested ecosystems. A review of 40 papers and 67 Burned Area Reports reporting species seeded between 1970 and 2007 revealed a trend of increasing use of native species, annual cereal grains and sterile-grass hybrids, with natives dominating seed mixes. According to 380 Burned Area Reports with data on costs and area seeded, total post-fire seeding expenditures have increased substantially, averaging US

Evaluating the effectiveness of postfire rehabilitation treatments.

3.3 million per year spent on post-fire emergency seeding treatments in forested ecosystems that involved the Forest Service during the period 2000 to 2007 – an increase of 192% compared with the average spent during the previous 30 years. The percentage of the total burned area seeded averaged 21% in the 1970s, compared with only 4% between 2000 and 2007.