Resilience of lake biogeochemistry to boreal-forest wildfires during the late Holocene.

ABSTRACT: Novel fire regimes are expected in many boreal regions, and it is unclear how biogeochemical cycles will respond. We leverage fire and vegetation records from a highly flammable ecoregion in Alaska and present new lake-sediment analyses to examine biogeochemical responses to fire over the past 5300 years. No significant difference exists in δ¹³C, %C, %N, C : N, or magnetic susceptibility between pre-fire, post-fire, and fire samples. However, δ¹⁵N is related to the timing relative to fire (χ² = 19.73, p < 0.0001), with higher values for fire-decade samples (3.2 ± 0.3‰) than pre-fire (2.4 ± 0.2‰) and post-fire (2.2 ± 0.1‰) samples. Sediment δ¹⁵N increased gradually from 1.8 ± 0.6 to 3.2 ± 0.2‰ over the late Holocene, probably as a result of terres

SUBMITTER: Chipman ML 

PROVIDER: S-EPMC6731474 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature