期刊
SOIL SCIENCE
卷 174, 期 12, 页码 646-651出版社
LIPPINCOTT WILLIAMS & WILKINS
DOI: 10.1097/SS.0b013e3181c4a7f8
关键词
Thermal conductivity; soil moisture; black spruce; moss; boreal forest
类别
资金
- National Science Foundation [EAR-0630249, DEB-0423442, ARC-0632400, EPSCoR-0701898.]
- USDA Forest Service, Pacific Northwest Research Station [PNW01-JV11261952-231]
- Institute of Northern Engineering at the University of Alaska Fairbanks
- Directorate For Geosciences
- Office of Polar Programs (OPP) [0856864] Funding Source: National Science Foundation
Organic soil horizons function as important controls on the thermal state of near-surface soil and permafrost in high-latitude ecosystems. The thermal conductivity of organic horizons is typically lower than mineral soils and is closely linked to moisture content, bulk density and water phase. In this study, we examined the relationship between thermal conductivity and soil moisture for different moss and organic horizon types in black spruce ecosystems of interior Alaska. We sampled organic horizons from feather moss-dominated and Sphagnum-dominated stands and divided horizons into live moss and fibrous and amorphous organic matter. Thermal conductivity measurements were made across a range of moisture contents using the transient line heat source method. Our findings indicate a strong positive and linear relationship between thawed thermal conductivity (K-t) and volumetric water content. We observed similar regression parameters (beta or slope) across moss types and organic horizons types and small differences in beta(0) (y intercept) across organic horizon types. Live Sphagnum spp. had a higher range of K-t than did live feather moss because of the field capacity (laboratory based) of live Sphagnum spp. In northern regions, the thermal properties of organic soil horizons play a critical role in mediating the effects of climate warming on permafrost conditions. Findings from this study could improve model parameterization of thermal properties in organic horizons and enhance our understanding of future permafrost and ecosystem dynamics.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据