气候变化领域集成服务门户(CCPortal): Hardwood-softwood composition influences early-instar larval dispersal mortality during a spruce budworm outbreak

CCPortal

DOI	10.1016/j.foreco.2020.118035
	Hardwood-softwood composition influences early-instar larval dispersal mortality during a spruce budworm outbreak
	Zhang B.; MacLean D.A.; Johns R.C.; Eveleigh E.S.; Edwards S.
发表日期	2020
ISSN	0378-1127
卷号	463
英文摘要	Spruce budworm (Choristoneura fumiferana Clem.) defoliation of balsam fir (Abies balsamea (L.) Mill.) has been shown to be less severe in stands with higher hardwood (broadleaved trees) content during both building and declining phases of budworm outbreaks. Reduced defoliation associated with forest composition could be explained by habitat fragmentation and/or natural enemy hypotheses, which posit higher early-instar larval dispersal loss or more intense parasitism in hardwood-softwood mixed stands than in pure balsam fir stands, respectively. We carried out field studies in 27 hardwood, mixedwood, and softwood plots with varied balsam fir-hardwood composition to assess effects of forest composition on: 1) first- and second-instar larval dispersal loss, and 2) stage-specific spruce budworm density and parasitism rates. Results indicated that increasing hardwood content increased second-instar (L2) dispersal losses. Stand type significantly affected dispersal loss of L2 larvae, both measured directly for three years and sampled on balsam fir seedlings. Post-hoc pair-wise comparisons indicated that L2 dispersal loss was less in softwood than in mixedwood or hardwood stand types based on measurements on ground traps and less in softwood and mixedwood than in hardwood stands based on sampling budworm larvae on regeneration. This suggested that high early-instar larval dispersal loss is a plausible explanation for the decreased spruce budworm density and balsam fir defoliation associated with increasing hardwood content. Stand type did not significantly affect parasitism rates. © 2020 Elsevier B.V.
英文关键词	Abies balsamea; Choristoneura fumiferana; Defoliation; Habitat fragmentation; Parasitoids
语种	英语
scopus关键词	Ecosystems; Reforestation; Softwoods; Abies balsamea; Choristoneura fumiferana; Defoliation; Habitat fragmentation; Parasitoids; Hardwoods; defoliation; dispersal; forest ecosystem; habitat fragmentation; hypothesis testing; mortality; natural enemy; parasitism; pest outbreak; wood quality; Abies Balsamea; Defoliation; Ecosystems; Hardwoods; Reforestation; Softwoods; Abies balsamea; Choristoneura fumiferana
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/155354
作者单位	Faculty of Forestry and Environmental Management, University of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3, Canada; Natural Resources Canada, Canadian Forest Service-Atlantic Forestry Centre, P.O. Box 4000, Fredericton, NB E3B 5P7, Canada; Forest Protection Limited, Fredericton International Airport, 2502 Route 102 Highway, Lincoln, NB E3B 7E6, Canada
推荐引用方式 GB/T 7714	Zhang B.,MacLean D.A.,Johns R.C.,et al. Hardwood-softwood composition influences early-instar larval dispersal mortality during a spruce budworm outbreak[J],2020,463.
APA	Zhang B.,MacLean D.A.,Johns R.C.,Eveleigh E.S.,&Edwards S..(2020).Hardwood-softwood composition influences early-instar larval dispersal mortality during a spruce budworm outbreak.Forest Ecology and Management,463.
MLA	Zhang B.,et al."Hardwood-softwood composition influences early-instar larval dispersal mortality during a spruce budworm outbreak".Forest Ecology and Management 463(2020).