High‐resolution peat volume change in a northern peatland: Spatial variability, main drivers, and impact on ecohydrology

Autor: Harm Bartholomeus, Sjoerd E. A. T. M. van der Zee, Klaas Metselaar, Juul Limpens, Frank Berendse, Mats Nilsson, Jelmer Nijp
Rok vydání: 2019
Předmět:
Peat
010504 meteorology & atmospheric sciences
Water table
0208 environmental biotechnology
Climate change
Plant Ecology and Nature Conservation
peat volume change
02 engineering and technology
Aquatic Science
photogrammetry
01 natural sciences
ecohydrology
Laboratory of Geo-information Science and Remote Sensing
Ecohydrology
groundwater
Laboratorium voor Geo-informatiekunde en Remote Sensing
geostatistics
peatlands
spatial patterns
Ecology
Evolution
Behavior and Systematics
0105 earth and related environmental sciences
Earth-Surface Processes
WIMEK
Ecology
Vegetation
Bodemfysica en Landbeheer
PE&RC
compression
020801 environmental engineering
Soil Physics and Land Management
Bodemgeografie en Landschap
Snowmelt
Soil Geography and Landscape
Spatial ecology
Plantenecologie en Natuurbeheer
Environmental science
Spatial variability
Physical geography
Zdroj: Ecohydrology 12 (2019) 6
Ecohydrology, 12(6)
ISSN: 1936-0592
1936-0584
Popis: The depth of the groundwater table below the surface and its spatiotemporal variability are major controls on all major biogeophysical processes in northern peatlands, including ecohydrology, carbon balance, and greenhouse gas exchange. In these ecosystems, water table fluctuations are buffered by compression and expansion of peat. Controls on peat volume change and its spatial variability, however, remain elusive, hampering accurate assessment of climate change impact on functioning of peatlands. We therefore (1) analysed patterning of seasonal surface elevation change at high spatial resolution (0.5 m); (2) assessed its relationship with vegetation, geohydrology, and position within the peatland; and (3) quantified the consequences for peatland surface topography and ecohydrology. Changes in surface elevation were monitored using digital close-range photogrammetry along a transect in a northern peatland from after snowmelt up to midgrowing season (May–July). Surface elevation change was substantial and varied spatially from −0.062 to +0.012 m over the measurement period. Spatial patterns of peat volume change were correlated up to 40.8 m. Spatial variation of peat volume change was mainly controlled by changes in water table, and to a lesser extent to vegetation, with peat volume change magnitude increasing from lawn < hollow < flark. Our observations suggest that patchiness and vertical variability of peatland surface topography are a function of the groundwater table. In dry conditions, the variability of surface elevation increases and more localized groundwater flows may develop. Consequently, spatially variable peat volume change may enhance peatland water retention and thereby sustain carbon uptake during drought.
Databáze: OpenAIRE
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