2.1. Study Identification
We performed systematic literature searches in September 2023 on Scopus
and Web of Science using keywords: “wildfire” OR “fire” AND
“dissolved organic carbon” OR “nitrate” AND “concentration” AND
“export” OR “discharge” OR “stream” OR “river” OR “creek” OR
“watershed” to generate a list of peer-reviewed papers reporting the
effects of fire on nitrate and DOC in paired burned and unburned
watersheds. After combining the literature search results and removing
duplicate publications, a list of 226 initial papers were identified.
This list of publications was filtered by the following criteria (Fig.
S1): 1) the burn was a wildfire (i.e., no prescribed burns), 2) the
study design encompassed a paired watershed approach (burned and
unburned reference sites), 3) the study reported either nitrate and/or
DOC data, 4) data were reported as time-series (not only means and
standard deviations) to allow for incorporation of seasonal variability,
and 5) the study was located within North America (Fig. 1). While our
goal was to be a global study, only two publications were located
outside of North America after the first four criteria, indicating a gap
globally on the investigation of the effects of wildfire on these
parameters. After filtering based on these criteria, this meta-analysis
includes 18 publications that span 3 biomes, 62 watersheds, and 20
unique wildfires (Table 1; Fig. 1). Metadata and data extraction can be
found in a public repository
(Cavaiani et al.,
2024).