DOI: 10.1029/2017JG004319
Scopus记录号: 2-s2.0-85047638663
论文题名: Accelerated Nutrient Cycling and Increased Light Competition Will Lead to 21st Century Shrub Expansion in North American Arctic Tundra
作者: Mekonnen Z.A. ; Riley W.J. ; Grant R.F.
刊名: Journal of Geophysical Research: Biogeosciences
ISSN: 21698953
出版年: 2018
卷: 123, 期: 5 起始页码: 1683
结束页码: 1701
语种: 英语
英文关键词: Arctic carbon cycle
; climate change
; modeling PFT dynamics
; modeling shrubification
; nutrient cycling
Scopus关键词: climate change
; climate forcing
; compensation
; ecosystem modeling
; ecotone
; modeling
; nutrient cycling
; range expansion
; shrub
; tundra
; twenty first century
; Alaska
; Arctic
; North America
; United States
英文摘要: Recent changes in species composition, and increases in shrub abundance in particular, have been reported as a result of warming in Arctic tundra. Despite these changes, the driving factors that control shrubification and its future trajectory remain uncertain. Here we used an ecosystem model, ecosys, to mechanistically represent the processes controlling recent and 21st century changes in plant functional type using RCP8.5 climate forcing across North American Arctic tundra. Recent and projected warming was modeled to deepen the active layer (spatially averaged by ~0.35 m by 2100) and thereby increase nutrient availability. Shrub productivity was modeled to increase across much of the tundra, particularly in Alaska and tundra-boreal ecotones. Deciduous and evergreen shrubs increased from ~45% of total tundra ecosystem net primary productivity (NPP) in recent decades to ~70% by 2100. The increased canopy cover of shrubs reduced incoming shortwave radiation for low-lying plants, causing declines in graminoids NPP from a current 35% of tundra NPP to 18%, and declines in nonvascular plants from 20% to 12%. The faster-growing deciduous shrubs modeled with less efficient nutrient conservation dominated much of the low Arctic by 2100 where nutrient cycling became more rapid, while the slower-growing evergreen shrubs modeled with more efficient nutrient conservation dominated a wider latitudinal range that extended to the high Arctic where nutrient cycling remained slower. We conclude that high-latitude vegetation dynamics over the 21st century will depend strongly on soil nutrient dynamics, diversity in plant traits controlling nutrient uptake and conservation, and light competition. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113960
Appears in Collections: 气候减缓与适应
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作者单位: Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States; Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
Recommended Citation:
Mekonnen Z.A.,Riley W.J.,Grant R.F.. Accelerated Nutrient Cycling and Increased Light Competition Will Lead to 21st Century Shrub Expansion in North American Arctic Tundra[J]. Journal of Geophysical Research: Biogeosciences,2018-01-01,123(5)