DOI: 10.1111/gcb.13148
论文题名: Drought stress limits the geographic ranges of two tree species via different physiological mechanisms
作者: Anderegg L.D.L. ; Hillerislambers J.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2016
卷: 22, 期: 3 起始页码: 1029
结束页码: 1045
语种: 英语
英文关键词: Drought avoidance
; Drought tolerance
; Ecophysiology
; Functional trait
; Intraspecific trait variation
; Pinus ponderosa
; Ponderosa pine
; Populus tremuloides
; Trembling aspen
Scopus关键词: Gymnospermae
; Magnoliophyta
; Pinus ponderosa
; Populus tremuloides
; carbon
; climate change
; Colorado
; drought
; growth, development and aging
; metabolism
; physiological stress
; physiology
; plant dispersal
; ponderosa pine
; Populus
; tree
; Carbon
; Climate Change
; Colorado
; Droughts
; Pinus ponderosa
; Plant Dispersal
; Populus
; Stress, Physiological
; Trees
英文摘要: Range shifts are among the most ubiquitous ecological responses to anthropogenic climate change and have large consequences for ecosystems. Unfortunately, the ecophysiological forces that constrain range boundaries are poorly understood, making it difficult to mechanistically project range shifts. To explore the physiological mechanisms by which drought stress controls dry range boundaries in trees, we quantified elevational variation in drought tolerance and in drought avoidance-related functional traits of a widespread gymnosperm (ponderosa pine - Pinus ponderosa) and angiosperm (trembling aspen - Populus tremuloides) tree species in the southwestern USA. Specifically, we quantified tree-to-tree variation in growth, water stress (predawn and midday xylem tension), drought avoidance traits (branch conductivity, leaf/needle size, tree height, leaf area-to-sapwood area ratio), and drought tolerance traits (xylem resistance to embolism, hydraulic safety margin, wood density) at the range margins and range center of each species. Although water stress increased and growth declined strongly at lower range margins of both species, ponderosa pine and aspen showed contrasting patterns of clinal trait variation. Trembling aspen increased its drought tolerance at its dry range edge by growing stronger but more carbon dense branch and leaf tissues, implying an increased cost of growth at its range boundary. By contrast, ponderosa pine showed little elevational variation in drought-related traits but avoided drought stress at low elevations by limiting transpiration through stomatal closure, such that its dry range boundary is associated with limited carbon assimilation even in average climatic conditions. Thus, the same climatic factor (drought) may drive range boundaries through different physiological mechanisms - a result that has important implications for process-based modeling approaches to tree biogeography. Further, we show that comparing intraspecific patterns of trait variation across ranges, something rarely done in a range-limit context, helps elucidate a mechanistic understanding of range constraints. © 2016 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/61473
Appears in Collections: 影响、适应和脆弱性
There are no files associated with this item.
作者单位: Department of Biology, University of Washington, Box 351800, Seattle, WA, United States
Recommended Citation:
Anderegg L.D.L.,Hillerislambers J.. Drought stress limits the geographic ranges of two tree species via different physiological mechanisms[J]. Global Change Biology,2016-01-01,22(3)