摘要：Western Siberia contains the world's most extensive wetlands. Despite its
recognition as a significant global carbon reservoir, the spatial structure and
composition of micro-topographical elements in patterned wetlands have never
been analyzed in detail. To address this uncertainty, we applied a multi-scale
approach to make a general and realistic estimation of land cover in Western
Siberia. Our approach was based on using a regional wetland typology map
(1:2500 000 scale), further refined by satellite image classifications (LANDSAT TM,
ETM+ in 1:200 000 scale) on test areas designated in the boreal region of Western
Siberia. In addition, QuickBird imagery was used for evaluation the fraction of
area occupied by micro-topographical elements within patterned wetlands.
Finally, we estimated the areal fractions of these micro-landscapes composing
the vegetation mosaic of 20 classes on the wetland typology map for each
climatic region of the study area. The total area of peatlands was calculated at
68.5 × 106 ha, which is higher than earlier estimates. We found almost equal areal extents of
ridge–hollow and ridge–hollow–pool patterned wetlands in almost all climatic regions of
Western Siberia; in the northern boreal region, however, the ridge–hollow–pool wetland
type became dominant and exceeded the areal extent of ridge–hollow wetlands in a
proportion of 80–20%. Also, the open water fraction increased dramatically in the northern
boreal region. The results of this survey can be used in models of ecosystem carbon
dynamics and inventory of trace gas fluxes in wetlands.
