High Arctic wetlands: Their occurrence, hydrological characteristics and sustainability

Woo, Ming‐ko; Young, Kathy L.

doi:10.1016/j.jhydrol.2005.07.025

Cited by 114 publications

(139 citation statements)

References 26 publications

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“…In low-lying areas the underlying permafrost impedes drainage which results in poorly drained, highly saturated soils (Woo & Young, 2006). These wetland and wet sedge tundra areas support unusually productive habitats with a plant cover of 65% or more in the otherwise dry and barren environment.…”

Section: Study Areamentioning

confidence: 99%

“…It serves as a key travel route for polar bears during spring and summer and is a vital habitat for muskoxen and caribou. The PBP wetland area is bordered by hills that reach about 240 m above sea level; runoff from these hillslopes supplies both water and sediment into the adjacent wetland area (Woo & Young, 2006). Within the wetland zone, moss, grass, and sedge meadows alternate with sparsely vegetated dry ridges and numerous small ponds and lakes, creating a patchy land cover pattern.…”

Section: Study Areamentioning

confidence: 99%

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Spatio-temporal sensitivity of MODIS land surface temperature anomalies indicates high potential for large-scale land cover change detection in Arctic permafrost landscapes

Muster

Langer

Abnizova

et al. 2015

Remote Sensing of Environment

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The accelerated warming of the Arctic climate may alter the local and regional surface energy balances, for which changing land surface temperatures (LSTs) are a key indicator. Modeling current and anticipated changes in the surface energy balance requires an understanding of the spatio-temporal interactions between LSTs and land cover, both of which can be monitored globally by measurements from space. This paper investigates the accuracy of the MODIS LST/Emissivity Daily L3 Global 1 km V005 product and its spatio-temporal sensitivity to land surface properties in a Canadian High Arctic permafrost landscape. The land cover ranged from fully vegetated wet sedge tundra to barren rock. MODIS LSTs were compared with in situ radiometer measurements from wet tundra areas collected over a 2-year period from July 2008 to July 2010 including both summer and winter conditions. The accuracy of the MODIS LSTs was −1.1°C with a root mean square error of 3.9°C over the entire observation period. Agreement was lowest during the freeze-back periods where MODIS LST showed a cold bias likely due to the overrepresentation of clear-sky conditions. A multi-year analysis of LST spatial anomalies, i.e., the difference between MODIS LSTs and the MODIS LST regional mean, revealed a robust spatiotemporal pattern. Highest variability in LST anomalies was found during freeze-up and thaw periods as well as for open water surface in early summer due to the presence or absence of snow or ice. The summer anomaly pattern was similar for all three years despite strong differences in precipitation, air temperature and net radiation. Summer periods with regional mean LSTs above 5.0°C showed the greatest spatial diversity with four distinct 2.0°C classes. Summer anomalies ranged from −4.5°C to 2.6°C with an average standard deviation of 1.8°C. Dry ridge areas heated up the most, while wetland areas and dry areas of sparsely vegetated bedrock with a high albedo remained coolest. The observed summer LST anomalies can be used as a baseline against which to evaluate both past and future changes in land surface properties that relate to the surface energy balance. Summer anomaly classes mainly reflected a combination of albedo and surface wetness. The potential to use this tool to monitor surface drying and wetting in the Arctic should therefore be further explored. A multi-sensor approach combining thermal satellite measurements with optical and radar imagery promises to be an effective tool for a dynamic, process-based ecosystem monitoring scheme.

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Section: Study Areamentioning

confidence: 99%

Section: Study Areamentioning

confidence: 99%

Spatio-temporal sensitivity of MODIS land surface temperature anomalies indicates high potential for large-scale land cover change detection in Arctic permafrost landscapes

Muster

Langer

Abnizova

et al. 2015

Remote Sensing of Environment

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“…Many of these patchy wetlands also depend on various water storages (e.g., late-lying snowbeds, near-surface ground ice) to sustain water levels during warm, dry summers. Depletion of these storages with climate warming may result in the disappearance of these wetlands (Woo and Young, 2006).…”

Section: Surface Water and Hydrologic Flow Pathsmentioning

confidence: 99%

Advances in Canadian Peatland Hydrology, 2003-2007

Waddington¹,

Quinton²,

Price³

et al. 2009

Canadian Water Resources Journal

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Abstract:Peatlands represent over 90% of Canadian wetlands and are the focus of considerable hydrological and biogeochemical research. Research on evapotranspiration (ET) has shown that it can exceed annual precipitation (P) where there are replenishing flood events. Evaporation from open water ponds in boreal peatlands exceeds ET from vegetated riparian zones by about two times, but surrounding forests can shelter small ponds by reducing turbulence. In an open bog, evaporation was modelled by separating the surface into vascular vegetation, hummock moss and hollow moss surfaces, and showed that vascular plants contribute 60-80% of ET, mosses making up the remainder with hummock mosses dominant over hollows. Runoff from peatlands is enhanced by features ranging from headwater swamps, ice-cored peat plateaus, patchy arctic wetlands and even sections of riverine peatlands. Groundwater fluxes can be quite erratic, and depend on transient properties of the peat that depend on moisture content (e.g., unsaturated hydraulic conductivity) to unsteady saturated hydraulic properties (e.g., hydraulic conductivity, specific yield) caused by peat compression and dilation associated with water storage changes. Surface elevation adjustments can result in a more stable depth to water table, increase evaporation losses, increase methane emission, and attenuate pore-water concentration of contaminants. Research on Canadian peatlands has also made significant methodological advances, including measurement of hydraulic properties of living mosses and peat pore-water and pore dimension characteristics. A considerable multi-annual effort has also been made in evaluating carbon dynamics from Canadian peatlands. Summer moisture availability is important to determining carbon fluxes with some peatlands experiencing enhanced productivity following drought (water table drawdown). Sudden changes in water table elevation promote DOC production and export. Methane bubbles confound hydraulic gradients and flows by creating local pockets of pressure, which are then released episodically when the entrapped gas reaches a threshold content. Canadian peatland hydrology continues to be actively researched in lab, field and modelling studies.

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“…Wetlands require a constant, sufficient water supply and are found where water gains exceed losses (Woo, 2011). Consequently, the availability of water in the otherwise semi-arid environment of the Arctic is a determining factor in the location and productivity of these wetlands (Woo and Young, 2006;Woo and Young, 2012). In the Arctic, their growing season is limited to a maximum of 20 three months each year, during which an adequate supply of water is needed to sustain them as wetlands.…”

mentioning

confidence: 99%

“…In the Arctic, their growing season is limited to a maximum of 20 three months each year, during which an adequate supply of water is needed to sustain them as wetlands. These moist areas provide sustenance for Arctic fauna and play an important role in ecological function (Woo and Young, 2006;Woo and Young, 2012). With changes in climate anticipated in the High Arctic, land classes such as wet sedge meadows will likely respond dramatically, and changes in these wetlands will have cascading effects on terrestrial and hydrological features around them.…”

mentioning

confidence: 99%

Controls on spatial and temporal patterns of soil nitrogen availability in a High Arctic wetland

Hung

Atkinson

Scott

2017

Preprint

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Abstract. Increased soil nutrient availability, and associated increase in vegetation productivity, could create a negative feedback between Arctic ecosystems and the climate system, reducing the contribution of Arctic ecosystems to future climate change. To predict whether this feedback will develop, it is important to understand the environmental controls over nutrient cycling in High Arctic ecosystems, and how they vary over space and time. This study explores the environmental 10 controls over spatial patterns of soil nitrogen availability in a High Arctic wet sedge meadow and how they influence carbon exchange processes. Ion exchange resin membranes measured available inorganic nitrogen in soils throughout the growing season at a high spatial resolution, while environmental variables (e.g. active layer depth, soil temperature, soil moisture) and carbon flux measurements were taken at frequent intervals during the 2016 field season. Environmental measures correlated highly with total and late season nitrate levels (total season dry tracks nitrate R 2 = 0.533, total season wet tracks nitrate R 2 = 15 0.803, late season nitrate R 2 = 0.622), with soil temperatures at 5 cm depth having the greatest effect. Soil available nitrate and ammonium correlated highly with total and early season gross primary productivity (total season wet tracks R 2 = 0.685, early season dry tracks R 2 = 0.788, early season wet tracks R 2 = 0.785). Higher ammonium concentrations coincided with greater carbon dioxide uptake. Nitrate concentrations correlated strongly to soil moisture, but nitrate levels were much lower than ammonium concentrations, suggesting low rates of nitrification vs. mineralization. Similar patterns were observed 20 regardless of whether the wet-sedge meadow was classified as wet or dry, but the relationships were always stronger in areas classified as wet, indicating the importance of moisture and water availability on abiotic processes in High Arctic wet sedge meadows. Topography played an important role in the movement and transport of water, which influenced how nutrients were cycled and moved within the wetland. Generally, the low-lying areas had the highest inorganic nitrogen concentrations.These results suggest that finer scale processes altering nitrogen availability may influence the overall carbon balance of wet 25 sedge meadows in the High Arctic, and how these ecosystems may respond to changes in climate.

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High Arctic wetlands: Their occurrence, hydrological characteristics and sustainability

Cited by 114 publications

References 26 publications

Spatio-temporal sensitivity of MODIS land surface temperature anomalies indicates high potential for large-scale land cover change detection in Arctic permafrost landscapes

Spatio-temporal sensitivity of MODIS land surface temperature anomalies indicates high potential for large-scale land cover change detection in Arctic permafrost landscapes

Advances in Canadian Peatland Hydrology, 2003-2007

Controls on spatial and temporal patterns of soil nitrogen availability in a High Arctic wetland

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