INFORMATION NEEDS TO SUPPORT DEVELOPMENT OF AGRI-ENVIRONMENTAL INDICATORS: THE CANADIANEXPERIENCE

摘要

Information needs were identified within the course of developing national agri-environmental indicators by staff of Agriculture and Agri-Food Canada. For the most-part, biophysical data about the land resources used for farming were extracted from the Soil Landscapes of Canada, a 1:1,000,000 scale map series and associated databases about the soils and landforms of Canada. Climate information was obtained by processing Environment Canada 30 year climate normal station data to monthly averages summarized by ecodistrict, a broad spatial unit of similar physiography and soils. Socio-economic information about farm practices was obtained from Statistics Canada's Census of Agriculture and custom surveys . Considerable effort was required to transpose census information, collected on spatial units of enumeration, to the biophysical base of soil landscapes in order to integrate socioeconomic information with environmental information, a prerequisite to the calculation of most agri-environmental indicators. Because the soil landscape map polygons are fully nested within the Ecological Framework for Canada, results for many indicators can be portrayed at any level within this framework. A total of 14 indicators were developed covering issues of soil and water quality, greenhouse gas emissions, farm management, biodiversity and production intensity. Of particular importance were the indicators on greenhouse gas emissions from primary agriculture. National estimates were generated for C02, N20 and CH4 emissions as well as for changes in soil C levels over time. The greatest information gaps identified were the lack of detailed land use information and reliable, geographically-defined data about on-farm management practices. In this paper we describe the challenges that exist in Canada for undertaking environmental assessments about agriculture with particular reference to greenhouse gas emissions and soil carbon stocks. We describe the tools available to make national scale assessments and offer suggestions to other countries on how best to deal with inevitable information gaps.