Lane,P.N.J., Sheridan,G.J., Noske,P.J. and Sherwin,C.B.(2008): Phosphorus and nitrogen exports from SE Australian forests following wildfire. Journal of Hydrology, 361, 186-198.

『野火に伴う南東オーストラリアの森林からのリンと窒素の流出』


Summary
 Following a wildfire in south-eastern Australia that burnt over 1 million hectares o forested land in early 2003, two former research catchments (136 and 244 ha), in the East Kiewa valley, Victoria, were re-instrumented. Discharge, suspended sediment, bedload and nitrogen (N) and phosphorus (P) were measured for 3 years post-fire. The nutrient data consisted of 15-min estimation of particulate P and total Kjeldahl N via a regression with turbidity, and dissolved forms of P and N estimated from over 1100 water samples. The regression-based estimation allowed rigorous estimation of errors, seldom reported in water quality data. The fire appears to have increased the total P and N exports by around 5-6-fold, peaking at 1.6 kg ha-1 of P and 15.3 kg ha-1 of total combined N. Nutrients transported as particulate matter dominated the first post-fire year, with 94% of total combined P and 69% of total combined N. Although dissolved forms increased in importance, the particulate load comprised 86% of the total combined P load and 68% of the total combined N load over the three post-fire years. Concentrations and loads of P and N exhibited a rapid recovery to unburnt levels during the second post-fire year. Particulate forms declined sharply through a reduction in sediment delivery. Nitrate had the slowest relaxation time, suggesting a persistent subsurface pathway and the effect of nitrification. Notably, dissolved N fluxes were predominantly in baseflow even in the first post-fire year. The errors calculated for this study indicate the uncertainty that can exist in water quality estimation despite high resolution experimental design. Loads estimated from intermittent sampling should be treated with caution. A simple model with time as the single parameter proved to be a good predictor of mean three monthly concentrations.

Keywords: Wildfire; Phosphorus; Nitrogen; Eucalypt forests; Water quality』

Introduction
Site details
Methods
 Field
Laboratory
Turbidity
 Phosphorus
 Nitrogen
Data analysis
 Concentrations
 Load estimation
Results
 N and P relationships with turbidity
 Concentrations
 Model fitting
 Loads
 Phosphorus
 Nitrogen
 Partitioning of particulate and dissolved loads
 Temporal distribution of loads
Discussion
 Measurement and uncertainty
 Concentrations and loads
 Comparison with unburnt sites where
 Changes attributable to fire
 Comparison with other studies
Conclusions
Acknowledgements
References


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