气候变化领域集成服务门户(CCPortal): Detecting the influence of climate and humans on pine forests across the dry valleys of eastern Nepal's Koshi River basin

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DOI	10.1016/j.foreco.2019.03.013
	Detecting the influence of climate and humans on pine forests across the dry valleys of eastern Nepal's Koshi River basin
	Thapa U.K.; St. George S.
发表日期	2019
ISSN	0378-1127
起始页码	12
结束页码	22
卷号	440
英文摘要	Pine forests provide goods and services crucial to more than ten million people living in the middle-mountains (600–4000 m) of Nepal. These critically important forests are already often overexploited and could be at risk from future climate change. In order to investigate the combined effects of climate and human disturbances on the growth of pine forests, we established a new network of tree-ring sites in six Pinus wallichiana and four P. roxburghii forests across the dry inner valleys of eastern Nepal's Koshi River watershed. We produced measurements of total annual ring widths, and detrended individual tree-ring series with 67% cubic splines to produce site-level chronologies. The Koshi tree-ring chronologies were compared against local records of mean monthly temperature and total monthly rainfall to identify the main climatic factor(s) limiting pine growth. We also employed a relative growth change method to estimate growth releases and suppressions in ring-width series as indicators of disturbances. At all sites, trees are relatively young (median age was 102 years) and variations in ring-width provide estimates of tree growth over only the past century. Ring-width chronologies from the Koshi have a weak common signal strength in comparison to trees from the same species obtained from sites in the central Himalaya, and the climate-growth response of Koshi pines appears to be governed primarily by moisture balance during winter. Disturbance events evident in pine ring-width data are largely asynchronous, which suggests these forest have been historically perturbed by human influences rather than large-scale climatic or ecological influences. The sacred forest at Sikri contained the oldest living trees (118 years), had the lowest number of disturbance events, and preserved a stronger common signal, which provided additional evidence of the effects of humans on other pine forests in the Koshi basin. Based on our findings, we suggest that modeling the future growth and distribution of pine trees in eastern Nepal should consider winter moisture. Furthermore, management strategies to better conserve pine forests in eastern Nepal should incorporate the two competing influences of climate and human activities on tree growth. © 2019 Elsevier B.V.
英文关键词	Human disturbances; Koshi River watershed; Pine forests; Winter moisture
语种	英语
scopus关键词	Climate change; Landforms; Moisture; Rivers; Watersheds; Annual ring width; Human disturbances; Management strategies; Moisture balance; Monthly rainfalls; Pine forest; River watersheds; Tree-ring chronologies; Forestry; anthropogenic effect; chronology; climate change; coniferous forest; detection method; disturbance; future prospect; growth response; risk assessment; tree ring; valley; watershed; Forestry; Forests; Growth; Moisture; Pinus; Rings; Rivers; Trees; Himalayas; Kosi River; Nepal; Pinus wallichiana
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/156078
作者单位	Department of Geography, Environment and Society, University of Minnesota, 414 Social Sciences Building, 267 19th Ave S, Minneapolis, MN 55455, United States
推荐引用方式 GB/T 7714	Thapa U.K.,St. George S.. Detecting the influence of climate and humans on pine forests across the dry valleys of eastern Nepal's Koshi River basin[J],2019,440.
APA	Thapa U.K.,&St. George S..(2019).Detecting the influence of climate and humans on pine forests across the dry valleys of eastern Nepal's Koshi River basin.Forest Ecology and Management,440.
MLA	Thapa U.K.,et al."Detecting the influence of climate and humans on pine forests across the dry valleys of eastern Nepal's Koshi River basin".Forest Ecology and Management 440(2019).