Forest hydrology and biomass modeling: DOC and DON

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This research advances a simplified yet theoretically and numerically robust process-based modeling approach to quantify the production, release and transport of dissolved organic carbon (DOC) and nitrogen (DON) from uplands and wetlands, as affected by forest litter type, hydro-thermal ground conditions, and daily year-round weather, and climate change. This proposal originates from our review of recent literature, models and data, and our recent study on DOC, DON and water colour in streams and soil solutions in south-western Nova Scotia. This study revealed as-yet un-quantified seasonal and year-by-year contrasts in upland-wetland DOC concentrations, which peak in upland soil solutions during spring, or summer to fall, or late fall to early winter. Wetland DOC concentrations peak fairly consistently in summer to early fall. The proposed research involves: 1. A 5-year effort, to generate data for DOC-DON modeling for a wide range of litter types and site conditions, to be of use in climate-affected forest biomass, C, and nutrient cycling modeling. 2. A detailed DOC-DON sampling study, accompanied with a comprehensive hydro-thermal assessment for each of the proposed sampling sites (soil moisture, temperature, infiltration, percolation, interflow, etc.), as affected by daily weather, forest cover and ground-cover , and soil-layer attributes such as depth, bulk density, texture, organic matter and coarse fragments. Hydro-thermal projections will be verified by in-situ soil moisture and temperature monitoring and recording. 3. An in-depth review of published DOC and DON production and upland-wetland transport data and models, to allow for a detailed multi-model comparison. 4. A generalized application of the resulting DOC-DON model; this requires the discerning of DOC-affecting flow-path patterns, using the UNB developed process to delineate flow paths and wet-areas, at 10 m resolution or better. 5. Further exploring potential roles of the resulting DOC-DON model in several research and environmental management contexts.