Sensitivity of catchment-aggregated estimates of soil carbon dioxide efflux to topography under different climatic conditions
| Autor: | R. A. Bourbonniere, Kara L. Webster, Irena F. Creed, F. D. Beall |
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| Rok vydání: | 2008 |
| Předmět: |
Atmospheric Science
Drainage basin Soil Science Wetland STREAMS Aquatic Science Oceanography Soil respiration chemistry.chemical_compound Geochemistry and Petrology Transition zone Earth and Planetary Sciences (miscellaneous) Earth-Surface Processes Water Science and Technology Hydrology geography geography.geographical_feature_category Ecology Paleontology Forestry Soil carbon Geophysics chemistry Space and Planetary Science Soil water Carbon dioxide Environmental science |
| Zdroj: | Journal of Geophysical Research. 113 |
| ISSN: | 0148-0227 |
| DOI: | 10.1029/2008jg000707 |
| Popis: | [1] Soil respiration (Rs) is an important component of regional carbon budgets in forested landscapes. Within a sugar maple forest on the Algoma Highlands of the Canadian Shield, mosaics of topographic features create gradients in environmental conditions and carbon pools that influence the pattern of Rs within the region. The sensitivity of catchment-aggregated Rs (CAR) to different spatial partitioning schemes of the landscape under different climate scenarios was examined in two contrasting catchments: one dominated by uplands (C35); the other containing uplands, critical transition zones (transiently saturated areas in isolated depressions or adjacent to wetlands, streams and lakes) and wetlands. CAR was estimated using a six topographic feature representation of the catchments including crest, backslope, footslope, toeslope, inner and outer wetland. CAR was underestimated (−7.4%) or overestimated (30.8%) if coarser spatial partitions were used, but the amount of error differed between catchments and with climatic conditions. A single feature (upland) partitioning scheme performed poorly under all climatic conditions (warm-wet, warm-dry, cool-wet and cool-dry). A two feature (upland and wetland) partitioning scheme showed improvement, but a partitioning scheme with a minimum of three features (upland, transition and wetland) was needed for accurate estimates of CAR in topographically varying catchments. The critical transition zone had the highest rates of Rs under all climate scenarios, and the critical transition zone and wetland became increasingly larger contributors to CAR under warmer and drier conditions. These observations point to the importance of accounting for the differential contribution of topographic features to Rs in carbon budget models. Failure to do so may lead to inaccurate estimates of landscape-scale Rs. |
| Databáze: | OpenAIRE |
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