气候变化领域集成服务门户(CCPortal): Variable thinning and prescribed fire influence tree mortality and growth during and after a severe drought

CCPortal

DOI	10.1016/j.foreco.2020.118595
	Variable thinning and prescribed fire influence tree mortality and growth during and after a severe drought
	Knapp E.E.; Bernal A.A.; Kane J.M.; Fettig C.J.; North M.P.
发表日期	2021
ISSN	0378-1127
卷号	479
英文摘要	California's high density, fire-excluded forests experienced an extreme drought accompanied by warmer than normal temperatures from 2012 to 2015, resulting in the deaths of millions of trees. We examined tree mortality and growth of mixed-conifer stands that had been experimentally treated between 2011 and 2013 with two different thinning treatments, one with more structural variability (HighV) and one with less structural variability (LowV), applied alone or in combination with prescribed burning. Tree mortality between 2014 and 2018 varied by species ranging from 42% of white fir (Abies concolor) to 18% of sugar pine (Pinus lambertiana), 12% of incense cedar (Calocedrus decurrens) and 10% of yellow pine (P. ponderosa and P. jeffreyi). Lower overall tree mortality rates at this location relative to drier locations in the southern Sierra Nevada suggested that drought effects may have been ameliorated by lower water deficits due to our site's more northerly location and deep, productive soils in combination with reductions in tree competition following thinning and burning. Averaged across burn treatments, thinning reduced the overall mortality rate between 2014 and 2018 from 34% to 11%. A total of 23% of the basal area was lost in the unthinned control treatments during this time period, while basal area was unchanged in the thinned treatments, with growth offsetting mortality. There was no significant difference in mortality or basal area change between LowV and HighV, suggesting that leaving trees at variable spacing may not compromise growth or resilience of the stand during a drought. Overall tree mortality was greater in the prescribed burn treatments, most pronounced in the smaller tree size classes, and varied by species, with burning having a significant effect on incense cedar and all pines, but not white fir. Trees with greater competition (Hegyi index) were more likely to die, particularly when also burned. Burning, however, consumed surface fuels and lowered fire hazard. With predictions of warmer droughts and greater weather variability, reducing forest density (basal area) and keeping surface fuel loads low will be important for building greater resilience to future drought stress and wildfire. © 2020
英文关键词	Bark beetles; Fuels treatment; Mixed-conifer forest; Resilience; Stanislaus-Tuolumne Experimental Forest; Variable density thinning; Water stress
语种	英语
scopus关键词	Drought; Location; Odors; Population statistics; Control treatments; Pinus lambertiana; Prescribed burning; Southern sierra nevada; Structural variability; Thinning treatment; Variable spacing; Weather variability; Forestry; basal area; coniferous tree; drought; mortality; prescribed burning; spatiotemporal analysis; temperature effect; thinning; tree; Drought; Forestry; Mortality; Odors; Pinus Lambertiana; Prescribed Burning; Thinning; Trees; California; Sierra Nevada [California]; United States; Abies concolor; Abies grandis; Calocedrus decurrens; Coniferophyta; Pinus lambertiana; Scolytinae
来源期刊	Forest Ecology and Management
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/154887
作者单位	USDA Forest Service, Pacific Southwest Research Station, 3644 Avtech Parkway, Redding, CA 96002, United States; Humboldt State University, Department of Forestry and Wildland Resources, Arcata, CA 95521, United States; USDA Forest Service, Pacific Southwest Research Station, 1731 Research Park Drive, Davis, CA 95618, United States; USDA Forest Service, Pacific Southwest Research Station, 2500 Highway 203, Mammoth Lakes, CA 93546, United States
推荐引用方式 GB/T 7714	Knapp E.E.,Bernal A.A.,Kane J.M.,et al. Variable thinning and prescribed fire influence tree mortality and growth during and after a severe drought[J],2021,479.
APA	Knapp E.E.,Bernal A.A.,Kane J.M.,Fettig C.J.,&North M.P..(2021).Variable thinning and prescribed fire influence tree mortality and growth during and after a severe drought.Forest Ecology and Management,479.
MLA	Knapp E.E.,et al."Variable thinning and prescribed fire influence tree mortality and growth during and after a severe drought".Forest Ecology and Management 479(2021).