Data from: Ecosystem memory of wildfires affects resilience of boreal mixedwood biodiversity after retention harvest

The extent to which past states influence present and future ecosystem
characteristics (ecosystem memory (EM)) is challenging to assess because
signals of past ecological conditions fade with time. Using data about
seven different taxa, we show that ecological gradients initiated by
wildfires up to three centuries earlier affect biotic recovery after
variable retention harvest in the boreal mixedwood forest. First, we show
that fire history over the last 300 years is reflected in pre-harvest
species-specific stand basal area (BA), with longer times since high
severity fire associated with proportionally higher BA of shade-tolerant
softwood species than shade-intolerant hardwoods. Second, using patterns
in the BA of pre-harvest tree species we link fire history to species
composition of pre-harvest assemblages of bryophytes, herbs, shrubs,
regenerated trees, songbirds, spiders and carabid beetles. Finally, we use
variance partitioning to compare the importance of species-specific pre-
versus post-harvest BA for explaining the structure of these seven biotic
assemblages two, five and ten years after harvest. We detected persistent
significant effects of pre-harvest BA in all post-harvest biotic
assemblages up to ten years after harvest. Pre-harvest BA was more
strongly associated with early post-harvest understory plant and carabid
beetle assemblages than was post-harvest BA, but the opposite was true for
spiders, songbirds and regenerated trees. EM effects were detected two,
five and ten years after harvest but temporal patterns varied according to
taxa. Thus, EM of fire history can persist at least ten years after
variable retention harvest and such effects appear to be stronger for
understory plants than for animals. We conclude that management of
biological legacies to increase post-disturbance EM will increase overall
resilience and sustainability of these mixedwood forests.