Summary

The Sinks Table Foundation Paper (Environment Canada 1998) introduced wetlands as possible carbon sinks under the Kyoto Protocol. Neither agricultural soils nor wetland carbon sinks are currently acknowledged in the Protocol, but Canada's position is that forest carbon stocks include both the above - and below - ground biomass and soil carbon, and that agricultural soil carbon should be included. Wetlands cover about 14 per cent of Canada's land surface and contain more than 150 billion tonnes of carbon, approximately 60 per cent of Canada's carbon stock. Since wetlands are such prominent components of both forest and agricultural landscapes, one could expect that soil carbon under the Kyoto Protocol would also include wetlands, should agricultural soil management be confirmed as an accountable sink category or should carbon stocks encompass the soils pool.

Following the release of the Foundation Paper in November 1998, wetland carbon sinks have been the focus of further workshops and studies include the following:

• Climate Change Action Fund (CCAF) workshop on Carbon Flux Processes in Terrestrial Ecosystems. Downsview, 18-19 January 1999.


• Feasibility study on Wetlands and Climate Change (Patterson, 1999).


• Workshop on Carbon Sequestration in Prairie Wetlands. Oak Hammock, Manitoba, 19-20 April 1999.

The definition of wetlands and their distribution and abundance in Canada are described in the Foundation Paper. As steward of over 24 per cent of the world's wetlands, Canada has a unique responsibility for their conservation and sustainable use. Most of Canada's northern peatlands are not affected by man. Wetlands in the southern working landscapes have experienced the largest human impact, and as a result are the focus of this paper, as being part of the scope of the Framework Convention on Climate Change.

Although a formally recognized definition of wetlands is an important starting point, any consideration of carbon sinks and sources is a function of land-use practices and wetland conservation programs, or in the terms of the Protocol, human-induced land use and land-use change. Wetland conservation, as exemplified by the North American Waterfowl Management Plan (NAWMP) through its habitat Joint Ventures (JVs), is a landscape-scale enterprise, encompassing wetland basins, margins or riparian zones and associated uplands (Patterson, 1994). Through voluntary, non-regulatory partnerships with land owners and managers, the NAWMP JVs are globally acknowledged as leading demonstrations of the sustainable development of landscape resources (Tyrchniewicz and Wilson 1994). As a value-added component of sustainable agriculture and forestry, wetland conservation provides mutually beneficial land-use options for land managers.

Wetlands have the highest carbon density of all terrestrial ecosystems. With the exception of peatlands, wetlands are among the most productive ecosystems in the world, and have properties that reduce the rate of organic matter turnover. Hence, wetland ecosystems are characterized by the two primary factors controlling carbon sequestration: (1) high rates of organic matter input, and (2) reduced rates of decomposition. There is considerable opportunity for managing that capability to enhance carbon sequestration while sustaining other valued ecosystem functions (USDOE, 1999). Recognition of wetlands in the Kyoto Protocol would bolster their conservation and sustainable use, and would embrace a more comprehensive vision of sinks in the agreement.

The purpose of this paper is to address what makes a wetland a sink or a source of carbon, how this is affected by human-induced land use and land-use changes in the agricultural and forested working landscapes, and to outline the potential for emissions reduction and sink enhancement. The science sub-sections of this paper will focus on the natural cycle of greenhouse gases through wetlands, what affects this natural cycle and the potential measurement and verification techniques. The "options" presented in this paper will be based on wetlands in those landscapes that are affected by forestry and agriculture, the largest proportion of which are located in the prairie and parkland region.