Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1111/gcb.13537 |
Threshold loss of discontinuous permafrost and landscape evolution | |
Chasmer, Laura; Hopkinson, Chris | |
2017-07-01 | |
发表期刊 | GLOBAL CHANGE BIOLOGY |
ISSN | 1354-1013 |
EISSN | 1365-2486 |
出版年 | 2017 |
卷号 | 23期号:7 |
文章类型 | Article |
语种 | 英语 |
国家 | Canada |
英文摘要 | This study demonstrates linkages between the 1997/1998 El Nino/Southern Oscillation index and a threshold shift to increased permafrost loss within a southern Taiga Plains watershed, Northwest Territories, Canada. Three-dimensional contraction of permafrost plateaus and changes in vegetation structural characteristics are determined from multitemporal airborne Light Detection And Ranging (LiDAR) surveys in 2008, 2011 and 2015. Morphological changes in permafrost cover are compared with optical image analogues from 1970, 1977, 2000 and 2008 and time-series hydro-climate data. Results demonstrate that significant changes in air temperature, precipitation, runoff and a shortening of the snow-covered season by 35 days (1998-2014) and 50 days (1998 only) occurred after 1997. The albedo reduction associated with 35 and 50 days less snow cover leads to increases in shortwave energy receipt during the active thaw period of similar to 12% (3% annually) and similar to 16% (5% annually), respectively. From 2000 to 2015, sporadic permafrost loss accelerated from 0.19% (of total basin area) per year between 1970 and 2000 to 0.58% per year from 2000 to 2015, with a projected total loss of permafrost by similar to 2044. From similar to 1997 to 2011, we observe a corresponding shift to increased runoff ratio. However, observed increases in the proportion of snow precipitation and the volumetric contribution of permafrost loss to runoff post-1997 (0.6-6.4% per year) cannot fully explain this shift. This suggests increases in drainage efficiency and possible losses from long-term groundwater storage as a result of subtle terrain morphological and soil zone hydraulic conductivity changes. These hydrological changes appear coincident with high vegetation mortality at plateau margins combined with succession-related canopy growth in some bog and fen areas, which are presumed to be drying. Similar changes in runoff response were observed at adjacent Birch, Trout and Jean Marie River watersheds indicating that observations are representative of northern Boreal sporadic permafrost/wetland watersheds in the Taiga Plains. |
英文关键词 | boreal climate change ENSO hydrology light detection and ranging permafrost remote sensing tipping point |
领域 | 气候变化 ; 资源环境 |
收录类别 | SCI-E |
WOS记录号 | WOS:000402514900014 |
WOS关键词 | CLIMATE-CHANGE ; BOREAL PEATLANDS ; PEAT PLATEAU ; THAW ; TRENDS ; CANADA ; CLASSIFICATION ; DISEQUILIBRIUM ; FRAGMENTATION ; CONNECTIVITY |
WOS类目 | Biodiversity Conservation ; Ecology ; Environmental Sciences |
WOS研究方向 | Biodiversity & Conservation ; Environmental Sciences & Ecology |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/17357 |
专题 | 气候变化 资源环境科学 |
作者单位 | Univ Lethbridge, Dept Geog, Lethbridge, AB T1K 3M4, Canada |
推荐引用方式 GB/T 7714 | Chasmer, Laura,Hopkinson, Chris. Threshold loss of discontinuous permafrost and landscape evolution[J]. GLOBAL CHANGE BIOLOGY,2017,23(7). |
APA | Chasmer, Laura,&Hopkinson, Chris.(2017).Threshold loss of discontinuous permafrost and landscape evolution.GLOBAL CHANGE BIOLOGY,23(7). |
MLA | Chasmer, Laura,et al."Threshold loss of discontinuous permafrost and landscape evolution".GLOBAL CHANGE BIOLOGY 23.7(2017). |
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