DOI: 10.1016/j.foreco.2013.09.041
Scopus记录号: 2-s2.0-84888138025
论文题名: Long-term overstory and understory change following logging and fire exclusion in a Sierra Nevada mixed-conifer forest
作者: Knapp E.E. ; Skinner C.N. ; North M.P. ; Estes B.L.
刊名: Forest Ecology and Management
ISSN: 0378-1127
出版年: 2013
卷: 310 起始页码: 903
结束页码: 914
语种: 英语
英文关键词: Fire exclusion
; Forest densification
; Reference conditions
; Shrub cover
; Species richness
Scopus关键词: Fire exclusion
; Herbaceous species
; Land management practices
; Mixed-conifer forests
; Reference condition
; Shrub cover
; Species richness
; Understory vegetation
; Biodiversity
; Fires
; Vegetation
; Forestry
; abundance
; biodiversity
; coniferous forest
; ecosystem management
; ecosystem resilience
; fire behavior
; land management
; logging (timber)
; long-term change
; overstory
; species richness
; understory
; vegetation cover
; Biodiversity
; Fires
; Forestry
; Plants
; Shrubs
; Species Identification
; California
; Sierra Nevada [California]
; United States
; Coniferophyta
英文摘要: In many forests of the western US, increased potential for fires of uncharacteristic intensity and severity is frequently attributed to structural changes brought about by fire exclusion, past land management practices, and climate. Extent of forest change and effect on understory vegetation over time are not well understood, but such information is useful to forest management focused on restoring biodiversity and resilience to these ecosystems. We re-measured three large (4ha) historical "Methods of Cutting" (MC) plots in mixed-conifer forest of the central Sierra Nevada installed in 1929 to evaluate the effects of different logging methods. Trees ≥10cm were surveyed across the entire plots and understory vegetation (tree seedlings, shrubs, and herbaceous species) was quantified within quadrats in the old-growth condition in 1929 prior to logging, later in 1929 after logging, and again in 2007 or 2008. We also compared forest structure in the MC plots with an adjacent unlogged "control" area and collected fire scar samples from nearby stumps to evaluate the historical fire regime. The contemporary tree density in the MC plots (739treesha-1) was 2.4times greater than the 1929 pre-logging density (314treesha-1). Trees in the small and intermediate size classes (10-75cmdbh) were significantly over-represented, and trees in the larger size classes (>90cmdbh) generally significantly under-represented, compared with historical conditions. The proportion of pine dropped from 37% of tree basal area in 1929 to 21% in 2007/08. Density of small to intermediate sized trees was similar in the contemporary logged and unlogged control plots, suggesting that over the long term, ingrowth may have been influenced more by lack of fire than historical logging. Change to non-tree vegetation was most pronounced for shrub cover, which averaged 28.6% in 1929 but only 2.5% in 2008. CART analysis indicated that the highest shrub cover in 1929 was in areas having four or fewer trees growing within 15m to the south of the quadrat, suggesting that reduced light was the most likely explanation for the decline over time. Herbaceous species richness in 2008 was significantly lower than in 1931, two years after logging, but did not differ significantly from 1929, prior to logging. Understory vegetation should benefit from thinning or prescribed fire treatments that lead to a greater abundance of higher light environments within stands. © 2013. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/66267
Appears in Collections: 影响、适应和脆弱性
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作者单位: US Department of Agriculture, Forest Service, Pacific Southwest Research Station, 3644 Avtech Parkway, Redding, CA 96002, United States; US Department of Agriculture, Forest Service, Pacific Southwest Research Station, 1731 Research Park Dr., Davis, CA 95618, United States; US Department of Agriculture, Forest Service, Eldorado National Forest, 100 Forni Road, Placerville, CA 95667, United States
Recommended Citation:
Knapp E.E.,Skinner C.N.,North M.P.,et al. Long-term overstory and understory change following logging and fire exclusion in a Sierra Nevada mixed-conifer forest[J]. Forest Ecology and Management,2013-01-01,310