DOI: 10.1016/j.foreco.2014.12.008
Scopus记录号: 2-s2.0-84928970057
论文题名: Long-term dead wood changes in a Sierra Nevada mixed conifer forest: Habitat and fire hazard implications
作者: Knapp E.E.
刊名: Forest Ecology and Management
ISSN: 0378-1127
出版年: 2015
卷: 339 起始页码: 87
结束页码: 95
语种: 英语
英文关键词: Coarse woody debris
; Fire hazard
; Mixed conifer
; Reference conditions
; Snag
; Tree mortality
Scopus关键词: Debris
; Ecosystems
; Fire hazards
; Fires
; Hazards
; Wood
; Coarse woody debris
; Mixed conifer
; Reference condition
; Snag
; Tree mortality
; Forestry
; bird
; coarse woody debris
; coniferous forest
; coniferous tree
; dead wood
; decomposition
; fire behavior
; forest ecosystem
; forest management
; habitat type
; logging (timber)
; mammal
; mortality
; population decline
; snag
; wild population
; Mortality
; Softwoods
; Wood
; California
; Sierra Nevada [California]
; United States
; Aves
; Coniferophyta
; Mammalia
英文摘要: Dead trees play an important role in forests, with snags and coarse woody debris (CWD) used by many bird and mammal species for nesting, resting, or foraging. However, too much dead wood can also contribute to extreme fire behavior. This tension between dead wood as habitat and dead wood as fuel has raised questions about appropriate quantities in fire-dependent forested ecosystems. Three plots installed in mixed conifer forest of the central Sierra Nevada in 1929 illustrate how amounts and sizes of dead wood have changed through time as a result of logging and fire exclusion. Diameter of snags was measured and CWD was mapped in the old-growth condition, prior to logging. Snags were re-measured in 2007 or 2008, and CWD was re-mapped in 2012. Snag density increased from 15.2ha-1 in 1929 to 140.0ha-1 in 2007/2008. However, average snag size declined, with 72% and 22% of snags classified as medium or large in 1929 and 2007/2008, respectively. Mechanisms of tree mortality also appear to have changed with greater mortality in smaller size classes, possibly as a result of higher live tree density. CWD volume, mass, and cover did not differ significantly between 1929 and 2012, with increased tree mortality and lack of periodic consumption by fire apparently compensating for the loss of inputs of large wood due to past logging. However, number of logs increased from 28ha-1 to 76ha-1 and average size declined substantially. Because larger-sized dead wood is preferred by many wildlife species, the current condition of more, smaller, and more decayed woody pieces may have a lower ratio of habitat value relative to potential fire hazard than it once did. Size, density, and stage of decomposition are therefore potentially better metrics for managing dead wood than mass and/or volume alone. To restore dead wood to conditions more like those found historically will require growing larger trees and reducing the inputs of dead wood from small and intermediate-sized trees. Fire, which preferentially consumes smaller and more rotten wood, would also help shift the balance to larger and less decayed pieces. © 2014. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/65639
Appears in Collections: 影响、适应和脆弱性
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作者单位: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station, 3644 Avtech Parkway, Redding, CA, United States
Recommended Citation:
Knapp E.E.. Long-term dead wood changes in a Sierra Nevada mixed conifer forest: Habitat and fire hazard implications[J]. Forest Ecology and Management,2015-01-01,339