Spatial patterning of net primary production in wetlands of continental western Canada

Net primary production in wetlands of continental western Canada (Alberta, Saskatchewan, Manitoba) is mapped of wetlands, with peatlands representing and summarized by wetland type and ecoregion. The region contains 405 300 km(2) 90.1% of all wetlands. Based on a regional synthesis of published values, of net primary production, shrubby swamp and marsh wetlands produce more biomass annually through the process of net primary production than peatlands. Different peatland types appear to sequester similar amounts of plant biomass on an annual basis, with the exception of permafrost bogs that sequester less. Wetland net primary production for the region is calculated as 2.1 x 10(14) g yr(-1) of plant biomass, with 73.5% sequestered in peatlands. This is equivalent to 9.95 x 10(13) g yr-1 of carbon. Provincially this carbon is partitioned into 50%, for Manitoba, 30% for Alberta, and 20% for Saskatchewan. ON or the last 1000 years, an average of only 5% of this biomass (and carbon) accumulate as peat, with most lost through the process of decomposition. When the annual amount of carbon that accumulates a, peat is compared to the amount emitted provincially as anthropogenic greenhouse gases, wetlands present in each of the provinces accumulate 4% (Alberta), 8% (Saskatchewan), and 62% (Manitoba) of the emitted carbon annually. Wetlands in continental western Canada are a significant, active biosphere carbon sink following accumulation patterns of the last one thousand years. Future changes, particularly in fire frequency or intensity. may alter this accumulation pattern.