气候变化领域集成服务门户(CCPortal): Topographic variation in tree group and gap structure in Sierra Nevada mixed-conifer forests with active fire regimes

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DOI	10.1016/j.foreco.2020.118220
	Topographic variation in tree group and gap structure in Sierra Nevada mixed-conifer forests with active fire regimes
	Ng J.; North M.P.; Arditti A.J.; Cooper M.R.; Lutz J.A.
发表日期	2020
ISSN	0378-1127
卷号	472
英文摘要	In Sierra Nevada mixed-conifer forests, heterogeneity in overstory tree spatial patterns is an important ecological characteristic associated with resilience to frequent fires. Regional managers often emphasize this heterogeneity as a key component of forest treatments. There is a lack of information about how the dimensions of fire-resilient tree spatial patterns might vary with topography, which is an important influence on forest structure. We mapped, analyzed, and compared overstory tree spatial patterns across three topographic slope positions (ridges, mid-slopes, and valleys) in unlogged stands with multiple recent lower/mixed-severity burns. Using analysis of Individual trees, Clumps of trees, and Openings (ICO), we found significant differences in a number of spatial pattern metrics, including stand-level tree density and maximum clump size (highest in valleys), forest opening size (largest on ridges), and species composition (percent shade-intolerant stems highest on ridges). We found notably non-significant differences in within-clump tree densities at all spatial scales. Additionally, stand-level averages for forest structure across topography did not consistently capture spatial patterns for individual trees or smaller clump sizes, but often matched trends for clumps and openings in the largest size classes. As “megafires” become more common, prescribed fire and thinning treatments will be used more often to increase forest resilience. By quantifying variable tree spatial patterns across topographic positions in frequent-fire forests, we provide general guidelines for marking prescriptions that may increase resilience of treated forests to increasing fire intensity. © 2020 Elsevier B.V.
关键词	Fires Topography Ecological characteristics Forest structure Forest treatment Sierra Nevada mixed conifers Species composition Thinning treatment Topographic positions Topographic slope Forestry coniferous forest ecosystem resilience heterogeneity overstory shade tolerance spatial analysis stand structure thinning topographic effect wildfire Clumps Fires Forestry Forests Patterns Resilience Topography Trees Sierra Nevada Coniferophyta
语种	英语
来源机构	Forest Ecology and Management
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/132750
推荐引用方式 GB/T 7714	Ng J.,North M.P.,Arditti A.J.,et al. Topographic variation in tree group and gap structure in Sierra Nevada mixed-conifer forests with active fire regimes[J]. Forest Ecology and Management,2020,472.
APA	Ng J.,North M.P.,Arditti A.J.,Cooper M.R.,&Lutz J.A..(2020).Topographic variation in tree group and gap structure in Sierra Nevada mixed-conifer forests with active fire regimes.,472.
MLA	Ng J.,et al."Topographic variation in tree group and gap structure in Sierra Nevada mixed-conifer forests with active fire regimes".472(2020).