气候变化领域集成服务门户(CCPortal): Strong degradation of palsas and peat plateaus in northern Norway during the last 60 years

CCPortal

DOI	10.5194/tc-11-1-2017
	Strong degradation of palsas and peat plateaus in northern Norway during the last 60 years
	Borge A.F.; Westermann S.; Solheim I.; Etzelmüller B.
发表日期	2017
ISSN	19940416
卷号	11 期号:1
英文摘要	Palsas and peat plateaus are permafrost landforms occurring in subarctic mires which constitute sensitive ecosystems with strong significance for vegetation, wildlife, hydrology and carbon cycle. Firstly, we have systematically mapped the occurrence of palsas and peat plateaus in the northernmost county of Norway (Finnmark, ∼50000km2) by manual interpretation of aerial images from 2005 to 2014 at a spatial resolution of 250m. At this resolution, mires and wetlands with palsas or peat plateaus occur in about 850km2 of Finnmark, with the actual palsas and peat plateaus underlain by permafrost covering a surface area of approximately 110km2. Secondly, we have quantified the lateral changes of the extent of palsas and peat plateaus for four study areas located along a NW-SE transect through Finnmark by utilizing repeat aerial imagery from the 1950s to the 2010s. The results of the lateral changes reveal a total decrease of 33-71% in the areal extent of palsas and peat plateaus during the study period, with the largest lateral change rates observed in the last decade. However, the results indicate that degradation of palsas and peat plateaus in northern Norway has been a consistent process during the second half of the 20th century and possibly even earlier. Significant rates of areal change are observed in all investigated time periods since the 1950s, and thermokarst landforms observed on aerial images from the 1950s suggest that lateral degradation was already an ongoing process at this time. The results of this study show that lateral erosion of palsas and peat plateaus is an important pathway for permafrost degradation in the sporadic permafrost zone in northern Scandinavia. While the environmental factors governing the rate of erosion are not yet fully understood, we note a moderate increase in air temperature, precipitation and snow depth during the last few decades in the region. © Author(s) 2017.
学科领域	aerial photograph; degradation; erosion; mire; palsa; peatland; permafrost; spatial resolution; spatiotemporal analysis; surface area; thermokarst; Finnmark; Norway
语种	英语
scopus关键词	aerial photograph; degradation; erosion; mire; palsa; peatland; permafrost; spatial resolution; spatiotemporal analysis; surface area; thermokarst; Finnmark; Norway
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119469
作者单位	Department of Geosciences, University of Oslo, P.O. Box 1047, Oslo, 0316, Norway
推荐引用方式 GB/T 7714	Borge A.F.,Westermann S.,Solheim I.,et al. Strong degradation of palsas and peat plateaus in northern Norway during the last 60 years[J],2017,11(1).
APA	Borge A.F.,Westermann S.,Solheim I.,&Etzelmüller B..(2017).Strong degradation of palsas and peat plateaus in northern Norway during the last 60 years.Cryosphere,11(1).
MLA	Borge A.F.,et al."Strong degradation of palsas and peat plateaus in northern Norway during the last 60 years".Cryosphere 11.1(2017).