The complexity of biological disturbance agents, fuels heterogeneity, and fire in coniferous forests of the western United States.

Autor: Shaw DC; Department of Forest Engineering, Resources, and Management, Oregon State University, 216 Peavy Forest Science Complex, 3100 SW Jefferson Way, Corvallis, OR 97331, USA., Beedlow PA; U.S. Environmental Protection Agency, 200 SW 35th Street, Corvallis, OR 97333, USA., Lee EH; U.S. Environmental Protection Agency, 200 SW 35th Street, Corvallis, OR 97333, USA., Woodruff DR; USDA Forest Service, Pacific Northwest Research Station, Forestry Sciences Laboratory, 3200 SW Jefferson Way, Corvallis, OR 97333, USA., Meigs GW; Washington State Department of Natural Resources, 1111 Washington St. SE, Olympia, WA 98504, USA.; Department of Forest Ecosystems and Society, Oregon State University, 321 Richardson Hall, 3180 SW Jefferson Way, Corvallis, OR 97331, USA., Calkins SJ; Department of Forest Engineering, Resources, and Management, Oregon State University, 216 Peavy Forest Science Complex, 3100 SW Jefferson Way, Corvallis, OR 97331, USA., Reilly MJ; USDA Forest Service, Pacific Northwest Research Station, Forestry Sciences Laboratory, 3200 SW Jefferson Way, Corvallis, OR 97333, USA., Merschel AG; Department of Forest Ecosystems and Society, Oregon State University, 321 Richardson Hall, 3180 SW Jefferson Way, Corvallis, OR 97331, USA., Cline SP; U.S. Environmental Protection Agency, 200 SW 35th Street, Corvallis, OR 97333, USA., Comeleo RL; U.S. Environmental Protection Agency, 200 SW 35th Street, Corvallis, OR 97333, USA.
Jazyk: angličtina
Zdroj: Forest ecology and management [For Ecol Manage] 2022 Dec 01; Vol. 525, pp. 1-27.
DOI: 10.1016/j.foreco.2022.120572
Abstrakt: Forest biological disturbance agents (BDAs) are insects, pathogens, and parasitic plants that affect tree decline, mortality, and forest ecosystems processes. BDAs are commonly thought to increase the likelihood and severity of fire by converting live standing trees to more flammable, dead and downed fuel. However, recent research indicates that BDAs do not necessarily increase, and can reduce, the likelihood or severity of fire. This has led to confusion regarding the role of BDAs in influencing fuels and fire in fire-prone western United States forests. Here, we review the existing literature on BDAs and their effects on fuels and fire in the western US and develop a conceptual framework to better understand the complex relationships between BDAs, fuels and fire. We ask: 1) What are the major BDA groups in western US forests that affect fuels? and 2) How do BDA-affected fuels influence fire risk and outcomes? The conceptual framework is rooted in the spatiotemporal aspects of BDA life histories, which drive forest impacts, fuel characteristics and if ignited, fire outcomes. Life histories vary among BDAs from episodic, landscape-scale outbreaks (bark beetles, defoliators), to chronic, localized disturbance effects (dwarf mistletoes, root rots). Generally, BDAs convert aboveground live biomass to dead biomass, decreasing canopy fuels and increasing surface fuels. However, the rate of conversion varies with time-since-event and among BDAs and forest types, resulting in a wide range of effects on the amount of dead fuels at any given time and place, which interacts with the structure and composition of the stand before and subsequent to BDA events. A major influence on fuels may be that BDAs have emerged as dominant agents of forest heterogeneity creation. Because BDAs play complex roles in fuels and fire heterogeneity across the western US which are further complicated by interactions with climate change, drought, and forest management (fire suppression), their impacts on fuels, fire and ecological consequences cannot be categorized simply as positive or negative but need to be evaluated within the context of BDA life histories and ecosystem dynamics.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Databáze: MEDLINE
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