Collaborative Research: Spatial and Temporal Influences of Thermokarst Features on Surface Processes in Arctic Landscapes

最近的国际研究总结清楚地记录了北极气候变暖的过去和未来的程度。这些总结表明，在未来，气温上升将伴随着降水增加，主要是降雨：整个北极地区增加20%，沿海地区在冬季和秋季增加30%。这些气候变化将对北极系统产生重要影响。这项研究的直接利益在于变暖将促进永久冻土退化和解冻的可能性。原先冻结的土壤可能因降水增加而进一步不稳定，导致山坡热岩溶破坏。最近的研究表明，热岩溶失败是丰富的，并且似乎在北坡东部的Toolik湖和阿拉斯加西部的Noatak河流域周围变得越来越多。热岩溶破坏发生率的广泛和长期增加可能对北极水源景观的结构和功能产生重要影响。这项研究将使用系统的方法来解决关于热岩溶破坏如何影响北极景观的结构和功能的假设。它将侧重于植被的组成，土壤养分的分布和加工，以及沉积物和养分向河流和湖泊生态系统的出口。在这个山坡尺度上获得的结果将与在景观尺度上观察到的模式联系起来，以检验关于北极山麓热岩溶破坏空间分布的假设。了解这些相互作用很重要，因为陆地表面过程变化和热岩溶破坏形成的最大潜在影响可能是通过能量、反照率、水和微量气体交换反馈给气候系统。本研究旨在量化气候学、山坡水文、地貌、冻土、植被群落生态学、土壤养分动力学、微生物生态学、微量气体动力学和水生生态学之间的联系。它将采用现场实验、遥感和模拟建模相结合的方法来量化这些关系。

Recent summaries of international research clearly document the past and future extent of climate warming in the Arctic. These summaries suggest that in the future, rising temperatures will be accompanied by increased precipitation, mostly as rain: 20% more over the Arctic as a whole and up to 30% more in coastal areas during the winter and autumn. These climate changes will have important impacts on Arctic Systems. Of direct interest to this research is the likelihood that warming will promote permafrost degradation and thaw. Formerly frozen soils may be further destabilized by increased precipitation, leading to hillslope thermokarst failures. Recent work has documented that thermokarst failures are abundant and appear to have become more numerous around Toolik Lake on the eastern North Slope and in the western Noatak River basin in Alaska. A widespread and long-term increase in the incidence of thermokarst failures may have important impacts on the structure and function of arctic headwater landscapes. This research will use a systems approach to address hypotheses about how thermokarst failures influence the structure and function of the arctic landscape. It will focus on the composition of vegetation, the distribution and processing of soil nutrients, and exports of sediments and nutrients to stream and lake ecosystems. Results obtained at this hillslope scale will be linked to patterns observed at the landscape scale to test hypotheses about the spatial distribution of thermokarst failures in the arctic foothills. It is important to understand these interactions because perhaps the greatest potential impacts of changing land surface processes and formation of thermokarst failures are feedbacks to the climate system through energy, albedo, water, and trace gas exchange.This research is designed to quantify linkages among climatology, hillslope hydrology, geomorphology, geocryology, community ecology of vegetation, soil nutrient dynamics, microbial ecology, trace gas dynamics, and aquatic ecology. It will employ a combination of field experimentation, remote sensing, and simulation modeling as a means to quantify these relationships.