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Active Layer/Landscape Interactions: A Retrospective and Contemporary Approach in Arctic Alaska

活动层/景观相互作用：阿拉斯加北极地区的回顾性和当代方法

基本信息

批准号：
9612647
负责人：
Frederick Nelson
金额：
$ 52.12万
依托单位：
SUNY at Albany
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
1996
资助国家：
美国
起止时间：
1996-06-01 至 1998-12-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9612647&HistoricalAwards=false
关键词：
Active Layer Landscape Interactions Retrospective

项目摘要

This project addresses the central hypotheses of the Arctic System Science LAII Flux Study by examining spatial (local and regional) and temporal (interannual to interdecadal) variations in soil active layer thickness. this is done on representative landscapes by using different probing and soil coring approaches (grids, transects, and point data). Standard 1 km x 1 km grids are located in different landscape units across the Alaska Arctic Slope. the LAII sites, which are shared by other Flux Study projects, were selected in most cases based on availability of long-term data sets including soil thaw and local climate records. The study relies upon high frequency, site specific determination of active layer thickness as a function of climate, soil properties, and landscape units (geobotanical complexes). the historical boundary between the base of the recelt soil thaw and the upper permafrost is established by coring the frozen ground and observing the distribution and morphology of the ground ice. The thaw depth measurements are used to validate or modify active layer models and to assess climate change upon the arctic tundra ecosystem. The carbon status of the soils and near-surface permafrost are established across landscape units and serve as a basis for carbon balance extrapolations to regional scales.

该项目通过研究土壤活性层厚度的空间（地方和区域）和时间（年际至年代际）变化，探讨北极系统科学LAII通量研究的核心假设。这是通过使用不同的探测和土壤取芯方法（网格、样带和点数据）对代表性景观进行的。标准的1 km x 1 km网格位于阿拉斯加北极斜坡的不同景观单元中。 LAII站点与其他通量研究项目共享，在大多数情况下，选择LAII站点是基于长期数据集的可用性，包括土壤解冻和当地气候记录。这项研究依赖于高频率，现场特定的确定活动层厚度作为气候，土壤性质和景观单元（地植物复合体）的功能。通过对冻土的取芯和观测地面冰的分布和形态，建立了再融土融化底部与上部多年冻土之间的历史边界。融化深度的测量被用来验证或修改活动层模式，并评估气候变化对北极冻原生态系统的影响。土壤和近地表永久冻土的碳状况建立在景观单元之间，并作为区域尺度碳平衡外推的基础。