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Controls and Dynamics of Canopy-Derived Dissolved Organic Matter From Co-Dominant Broadleaved Deciduous Canopies to the Soil of a Temperate Catchment in the Northeastern United States
Publications in Climatology (2011)
  • John T. Van Stan, II, Georgia Southern University
Abstract
Terrestrially-derived dissolved organic matter (DOM) (composed of dissolved organic carbon (DOC) and nitrogen (DON)) flux and quality exert significant influence over carbon (C) and nitrogen (N) cycling, and related stream and soil ecologies. Yet, no study known to the author has simultaneously investigated all forest canopy-derived DOM inputs (throughfall, stemflow, and litter leachate) from trees of contrasting canopy structure to the soils of wooded ecosystems across temporal scales (annual, seasonal, and within-event scales). This dissertation attempts to fill this knowledge gap for a mid-latitude temperate deciduous forest by quantifying all canopy-derived annual, seasonal and intra-storm DOM fluxes, characterizing their relative aromaticity (SUVA254) and molecular weight (E2:E3 and SR) via UV-vis spectroscopic metrics, and estimating their contributions to soil solution 1 meter from the stemflow infiltration pathway using end member mixing analysis (EMMA) for two trees of contrasting canopy structure (Liriodendron tulipifera L., tulip poplar, and Fagus grandifolia Ehrh., American beech). DOC concentrations and fluxes produced markedly stronger seasonal patterns than DON seasonal differences for both species, especially in stemflow. Since seasonal DON fluxes were nearly negligible for both species in our study, diminished DOC:DON ratios were almost exclusively a result of seasonal DOC dynamics. Aromaticity (SUVA254) and relative molecular weight (E2:E3 and SR) of canopy-derived fluxes generally increased under leafless conditions, likely due to enrichment of lignin-degradation byproducts from greater bark contact. 
Disciplines
Publication Date
2011
Citation Information
John T. Van Stan. "Controls and Dynamics of Canopy-Derived Dissolved Organic Matter From Co-Dominant Broadleaved Deciduous Canopies to the Soil of a Temperate Catchment in the Northeastern United States" Publications in Climatology Vol. 63 Iss. 2 (2011)
Available at: http://works.bepress.com/john_vanstan/8/