Bridging the gap between models and measurements of peat hydraulic conductivity

摘要: Peat saturated hydraulic conductivity, Ksat, declines strongly with increasing degree of decomposition, providing a potentially important negative ecohydrological feedback that may buffer peatlands from climate-induced drying. However, the quantitative nature this relationship is poorly understood. We measured downcore changes in Ksat and carbon-to-nitrogen concentration quotients (C/N) 14 shallow (∼0.5 m deep, 0.1 diameter) peat cores Swedish raised bog. used C/N measurements to approximate fraction original mass remaining. A linear mixed effects (LME) model predicts log10(Ksat) (i) our C/N-derived estimate fractional remaining mass; (ii) depth; (iii) microhabitat (hummock, hollow); (iv) location (treeless bog center, treed margin). The LME indicated no significant random or interactions between predictors, so we derived nonlinear multiple regression (NLMR) predict on its scale. Both NLMR models decreases exponentially depth lower beneath hollows than hummocks for equivalent depths below surface. Fractional was an predictor model, but not model. distinction central marginal areas predictor. demonstrate first time log-linear, suggest revisions should be made peatland development models. In particular, depth—usually ignored modeling studies—exerted strong control over independently decomposition included explicitly algorithms.