气候变化领域集成服务门户(CCPortal): Retention of large, old trees in alternatives to clearcutting with a comparison of ground- and helicopter-based assessments

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DOI	10.1016/j.foreco.2020.118390
	Retention of large, old trees in alternatives to clearcutting with a comparison of ground- and helicopter-based assessments
	Baker S.C.; Chuter A.; Munks S.A.; Koch A.J.
发表日期	2020
ISSN	0378-1127
卷号	475
英文摘要	Habitat trees (mature live and dead trees with hollows) are a keystone habitat in Australian eucalypt forests where tree hollows typically occur in large, old trees. These trees provide potential habitat for hollow-using birds, bats and arboreal marsupials, including many threatened species. Habitat trees may be felled during forest harvesting and can also be negatively affected by wildfires. Shortages of habitat trees in harvesting landscapes can be a limiting factor for populations of hollow-using vertebrates. Retention forestry systems are expected to retain a greater number of habitat trees within sites than traditional clearcutting silviculture, but there is a need to quantify how the pattern of retention (dispersed trees vs. retained clumps) will affect the numbers and types of trees retained. The method of assessment (ground-based vs. aerial surveys) may influence the estimated numbers of habitat trees. We investigated habitat tree retention at the Warra Silvicultural Systems Trial in Southern Tasmania, Australia. This trial was instrumental in developing alternatives to clearcutting in tall, wet, old-growth eucalypt forests. Our research has two objectives. Objective 1 is to assess the numbers of habitat trees retained in various alternatives to clearcutting by comparing: unlogged control areas, 0.5–1 ha clumps retained within a harvested matrix (aggregated retention), trees scattered throughout the harvested area (dispersed retention), and small ~0.08 ha machinery exclusion zones where trees were retained if they were not of commercial value (clearcutting with understorey islands). Objective 2 is to compare ground-based to aerial, helicopter-based, assessment of large live and dead trees. Although low replication of harvest treatments precluded statistical comparison of silvicultural systems, the results, based on 1,260 trees, were clear. Of the various alternatives to clearcutting, aggregated retention retained the greatest proportion of all classes of habitat trees, primarily because of higher retention targets, but possibly also because of greater survival with reduced wind exposure in aggregates. Substantially fewer habitat trees were retained with dispersed retention, and virtually none with understorey islands in clearcutting. Aerial and ground-based assessment methods provided similar estimates of numbers of trees with visible hollows in aggregates and understorey islands (R2 = 0.95). Choice of method for future studies should consider available resources and objectives, since there were advantages and disadvantages of each approach. In conclusion, aggregated retention was found to be the preferred silvicultural system for retaining habitat trees within sites for hollow-using vertebrates, and helicopter surveys provide a rapid alternative to traditional ground-based assessment. © 2020 Elsevier B.V.
关键词	Aggregates Animals Antennas Conservation Ecosystems Harvesting Machinery Surveys Aggregated retention Dispersed retention Harvest treatments Retention forestries Silvicultural system Statistical comparisons Tasmania , Australia Threatened species Forestry Aves Metatheria Vertebrata
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/132613
推荐引用方式 GB/T 7714	Baker S.C.,Chuter A.,Munks S.A.,et al. Retention of large, old trees in alternatives to clearcutting with a comparison of ground- and helicopter-based assessments[J]. Forest Ecology and Management,2020,475.
APA	Baker S.C.,Chuter A.,Munks S.A.,&Koch A.J..(2020).Retention of large, old trees in alternatives to clearcutting with a comparison of ground- and helicopter-based assessments.,475.
MLA	Baker S.C.,et al."Retention of large, old trees in alternatives to clearcutting with a comparison of ground- and helicopter-based assessments".475(2020).