Disappearing Arctic tundra ponds: Fine-scale analysis of surface hydrology in drained thaw lake basins over a 65year period (1948-2013)
Disappearing Arctic tundra ponds: Fine-scale analysis of surface hydrology in drained thaw lake basins over a 65year period (1948-2013)
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DOI：
10.1002/2014jg002778
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发表时间：
2015-03-01
影响因子：
3.7
通讯作者：
Lougheed, Vanessa L.
中科院分区：
文献类型：
--
作者：
Andresen, Christian G.;Lougheed, Vanessa L.
北极苔原池塘（小于1公顷）地表水文的长期精细尺度动态在很大程度上是未知的，但是，这些小水体可能会大大有助于碳通量，能量平衡，和北极系统的生物多样性。通过比较历史航空图像（1948年）和现代亚米分辨率卫星图像（2002年，2008年和2010年），在整个上巴罗半岛，阿拉斯加，池塘面积和丰度的变化进行了评估。对低空风筝传播图像的摄影测量分析与国际生物计划历史研究地点七个池塘的池塘水和解冻深度断面的实地观察（2010-2013年）相结合，对此进行了补充。对22个不同地质时代的排水解冻湖盆（DTLB）中的2800多个池塘进行了分析。我们观察到的净减少30.3%的面积和17.1%的池塘数量在62年的时间。1972年从一个历史研究地点对池塘面积进行的实地观察证实了面积的线性下降趋势。池塘面积和数量取决于DTLB的年龄，但是，通过时间的变化是独立的DTLB年龄，潜在的长期影响的假设地貌景观演替的解冻湖循环。这些损失与池塘中的空气温度、活动层、水生挺水植物的密度和覆盖度的增加相一致。由于更温暖和更长的夏天，永冻层退化，以及入侵的水生新兴水生植物的蒸腾作用增加蒸发可能是导致表面积和池塘数量下降的因素。
Long-term fine-scale dynamics of surface hydrology in Arctic tundra ponds (less than 1ha) are largely unknown; however, these small water bodies may contribute substantially to carbon fluxes, energy balance, and biodiversity in the Arctic system. Change in pond area and abundance across the upper Barrow Peninsula, Alaska, was assessed by comparing historic aerial imagery (1948) and modern submeter resolution satellite imagery (2002, 2008, and 2010). This was complemented by photogrammetric analysis of low-altitude kite-borne imagery in combination with field observations (2010-2013) of pond water and thaw depth transects in seven ponds of the International Biological Program historic research site. Over 2800 ponds in 22 drained thaw lake basins (DTLB) with different geological ages were analyzed. We observed a net decrease of 30.3% in area and 17.1% in number of ponds over the 62year period. The inclusion of field observations of pond areas in 1972 from a historic research site confirms the linear downward trend in area. Pond area and number were dependent on the age of DTLB; however, changes through time were independent of DTLB age, with potential long-term implications for the hypothesized geomorphologic landscape succession of the thaw lake cycle. These losses were coincident with increases in air temperature, active layer, and density and cover of aquatic emergent plants in ponds. Increased evaporation due to warmer and longer summers, permafrost degradation, and transpiration from encroaching aquatic emergent macrophytes are likely the factors contributing to the decline in surface area and number of ponds.