气候变化领域集成服务门户(CCPortal): Forestland-peatland hydrologic connectivity in water-limited environments: hydraulic gradients often oppose topography

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DOI	10.1088/1748-9326/ab699a
	Forestland-peatland hydrologic connectivity in water-limited environments: hydraulic gradients often oppose topography
	Hokanson K.J.; Peterson E.S.; Devito K.J.; Mendoza C.A.
发表日期	2020
ISSN	17489318
卷号	15 期号:3
英文摘要	It is common to conceptualize the water table as a subdued replica of surface topography, where groundwater recharges at, and flows from, topographic highs and flows to, and discharges at, topographic lows, in humid (i.e. wetter) environments. This concept is also regularly applied to peatland hydrology, where hydraulic gradients are shown to be towards the peatland. However, this may not be a realistic representation of hydrology for low-relief and sub-humid regions. While it is widely accepted that peatlands maintain internal water tables in drought conditions through a system of autogenic negative feedback loops, there is a general lack of knowledge concerning the controls on, and patterns of, forestland hydrologic process that drive the hydraulic gradients between wetlands and their adjacent forestlands in water-limited conditions in low-relief areas. This study identifies the hydrologic function (i.e. source or sink of water) of forested uplands and peatlands in the Boreal Plains region of Canada and demonstrates that during a mesic (non-drought) year most peatlands are, in fact, potential sources of groundwater to adjacent forestlands. Sixteen forestland-peatland pairs were selected to represent a spectrum of forested hummock and peatland morphometries, topographic positions, and geologic settings. Hydraulic gradients determined for each well pair during the ice-off season demonstrate that the dominant gradient under mesic climatic conditions is from peatlands to adjacent forestlands, opposite of the topographic gradient, and that the sink-source function of each land unit does not change seasonally. Water table depressions under each forested hummock indicate that boreal forestlands are not reliable sources of groundwater recharge, spatially or temporally, which supports previous research showing that peatlands are the primary water source for runoff; illustrating the need for alternative conceptualizations of catchment hydrology in water limited regions of the boreal. Social Media Summary. Forests are poor sources of water to boreal peatlands and landscapes due to water table depressions. © 2020 The Author(s). Published by IOP Publishing Ltd.
英文关键词	connectivity; forested hummocks; groundwater; groundwater mounding; peatlands; storage; sub-humid
语种	英语
来源期刊	Environmental Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/154206
作者单位	Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB T6G 2E3, Canada; Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
推荐引用方式 GB/T 7714	Hokanson K.J.,Peterson E.S.,Devito K.J.,et al. Forestland-peatland hydrologic connectivity in water-limited environments: hydraulic gradients often oppose topography[J],2020,15(3).
APA	Hokanson K.J.,Peterson E.S.,Devito K.J.,&Mendoza C.A..(2020).Forestland-peatland hydrologic connectivity in water-limited environments: hydraulic gradients often oppose topography.Environmental Research Letters,15(3).
MLA	Hokanson K.J.,et al."Forestland-peatland hydrologic connectivity in water-limited environments: hydraulic gradients often oppose topography".Environmental Research Letters 15.3(2020).