DOI: 10.1111/gcb.13814
论文题名: Warming drives a front of white spruce establishment near western treeline, Alaska
作者: Miller A.E. ; Wilson T.L. ; Sherriff R.L. ; Walton J.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2017
语种: 英语
英文关键词: Picea glauca
; Boreal forest
; Climate
; Range shift
; Recruitment
; Saplings
; Seedlings
英文摘要: Regional warming has led to increased productivity near the boreal forest margin in Alaska. To date, the effects of warming on seedling recruitment have received little attention, in spite of forecasted forest expansion. Here, we used stand structure and environmental data from 95 white spruce (Picea glauca) plots sampled across a longitudinal gradient in southwest Alaska to explore factors influencing spruce establishment and recruitment near western treeline. We used total counts of live seedlings, saplings, and trees, representing five life stages, to evaluate whether geospatial, climate, and measured plot covariates predicted abundance, using current abundance distributions as a surrogate for climate conditions in the past. We used generalized linear models to test the null hypothesis that conditions favorable for recruitment were similar along the environmental gradient represented by longitude, by exploring relationships between per-plot counts of each life stage and the covariates hypothesized to affect abundance. We also examined the relationship between growing degree days (GDD) and seedling establishment over a period of three decades using tree-ring chronologies obtained from cores taken at a subset of our sites (n = 30). Our results indicated that seedling, sapling, and tree abundance were positively correlated with temperature across the study area. The response to longitude was mixed, with earlier life stages (seedlings, saplings) most abundant at the western end of the gradient, and later life stages (trees) most abundant to the east. The differential relationship between longitude and life-stage abundance suggests a moving front of white spruce establishment through time, driven by changes in environmental conditions near the species' western range limit. Likewise, we found a positive relationship between periods of seedling establishment and GDD, suggesting that longer summers and/or greater heat accumulation might enhance establishment, consistent with the positive relationship we found between life-stage abundance and temperature. © 2017 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/61197
Appears in Collections: 影响、适应和脆弱性
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作者单位: National Park Service Inventory and Monitoring Program Southwest Alaska Network Anchorage, AK USA; Department of Natural Resource Management South Dakota State University Brookings, SD USA; Geography Department and Forest Watershed and Wildland Sciences Graduate Program Humboldt State University Arcata, CA USA
Recommended Citation:
Miller A.E.,Wilson T.L.,Sherriff R.L.,et al. Warming drives a front of white spruce establishment near western treeline, Alaska[J]. Global Change Biology,2017-01-01