Sources and Transformation of Dissolved Organic Carbon in the Harp Lake Forested Catchment: The Role of Soils

The 14C content of dissolved organic carbon (DOC) in streams, soil water and groundwaters in the Harp Lake catchment in Ontario, Canada, reflect a mixture of DOC sources, including both contemporary plant material and 14C-depleted soil organic matter. The concentration and isotopic content of DOC in streams is highly variable, reflecting the complex flow path of the source water entering the streams. The characteristics of groundwater DOC are set in the soil column, either through DOC production in the deeper soil layers, or through preferential decomposition and/or sorption of 14C-enriched DOC components from percolating waters. The relative magnitudes of decomposition, transport and sorption as sinks for DOC produced in forested catchment soils are estimated. -Author

Dissolved Organic Carbon Cycling in Forested Watersheds: A Carbon Isotope Approach

Dissolved organic carbon (DOC) is important in the acid‐base chemistry of acid‐sensitive freshwater systems; in the complexation, mobility, persistence, and toxicity of metals and other pollutants; and in lake carbon metabolism. Carbon isotopes (13C and 14C) are used to study the origin, transport, and fate of DOC in a softwater catchment in central Ontario. Precipitation, soil percolates, groundwaters, stream, beaver pond, and lake waters, and lake sediment pore water were characterized chemically and isotopically. In addition to total DOC, isotopic measurements were made on the humic and fulvic DOC fractions. The lake is a net sink for DOC. Δ14C results indicate that the turnover time of most of the DOC in streams, lakes, and wetlands is fast, less than 40 years, and on the same time scale as changes in acidic deposition. DOC in groundwaters is composed of older carbon than surface waters, indicating extensive cycling of DOC in the upper soil zone or aquifer

Centre internship / Stagiaire au CRDI

Thesis, Sheri Sarah Dankevy, 200

Investigating gender and development discourse : an examination of the International Development Research Centre's practices

This thesis explores how the discourse of Gender and Development (GAD) is practiced through the work of the International Development Research Centre (IDRC). The investigation focuses on the integration of gender considerations in four projects that use Information and Communication Technologies {ICTs) for economic and social development. The research process includes interviews, visits to the project teams, participant observation, and analysis of project and other IDRC documents. The data indicate that the implementation of GAD is dependent upon textually mediated procedures and the social and gendered contexts of the communities in which these projects are located. A number of emerging themes in the research findings include the significance of a gender expert, of women's organizations, and of establishing common conceptualizations of gender. The research suggests that the Centre should further open discursive spaces for a more holistic incorporation of GAD principles, as defined by academics and activists