This dataset contains soil leachate data that were collected to assess short- to mid-term wildfire impacts on soils in the seasonal Pacific Coastal Temperate Rainforest. Field campaigns occurred between April - May 2022 and October 2022 - January 2023 and targeted nine historic wildfire areas (fires occurring 2015 - 2022) that span a range of sizes and burn severities. Soils were sampled within stream catchments to evaluate potential soil-to-stream propagation of fire effects. Eight composite soil cores (three subsamples per composite) were collected at each fire site (four in burned soils, four in reference catchments) and split into 0 to 5 cm and 6 to 10 cm depths. Repeat soil cores were collected at the CT site before and after the first post-fire wetting. The dataset includes measured concentrations of dissolved organic carbon (DOC), nutrients (total and dissolved phosphorus and nitrogen, soluble reactive phosphorus, nitrite + nitrate, and ammonium), major cations (calcium, potassium, magnesium, sodium, aluminum) and anions (sulfate, chloride). There are also in situ measurements collected with a YSI multiparameter probe (temperature, pH, dissolved oxygen, specific conductance) and dissolved organic matter (DOM) optical properties (absorbance and fluorescence spectra) measured on a Horiba Aqualog. Derived DOM indices (SUVA254, spectral slopes), parallel factor analysis (PARAFAC) component scores, and fluorescence indices (BIX, HIX) are provided. Given the expectation that wildfire prevalence and severity will increase in this traditionally wet region, it is likely that the impacts observed in this study will become both enhanced and more widespread in the future.

This research is funded by NSERC Discovery, NSERC Canada Graduate Research Scholarship – Master's (CGS-M) and Alberta Graduate Excellence Scholarship (AGES)