Moderate-severity fires initiated contemporary subcanopy cohorts, but ensuing fires, harvesting, and climate interacted to facilitate high tree densities. Historically, all 20 study stands were under an Indigenous-influenced, frequent, lower-severity fire regime. I conducted three dendrochronological studies that reconstructed the historical fire regimes and dynamics of these forests to discern the origin of high tree densities and guide ecosystem restoration to enhance forest resilience to fire and climate change. In dry forests of southeastern British Columbia (BC) dense stands may be legacies of past high-severity fires and exist within the historical range of variability, or they may result from disruptions to historical fire regimes and indicate lost resilience. Doing so could make these shifting forest conditions and wildfire regimes less disruptive to individuals and society. Finally, it compels us to embrace management approaches that incorporate ongoing disturbances and anticipated effects of climatic changes, and to support dynamically shifting patchworks of forest and non-forest. It involves human communities actively working with the ecosystems they depend on, and the processes that shape them, to adapt landscapes, species, and human communities to climate change while maintaining core ecosystem processes and services. We give clear examples of these changes and suggest that managing for resilient forests is a construct that strongly depends on scale and human social values.
We discuss the role of the regional climate in episodically or abruptly reorganizing plant and animal biogeography and forest resilience and resistance to disturbances. Resilience in North American Forests disruptions. We highlight geographic similarities and important differences in the structure and organization of historical landscapes, their forest types, and in the conditions that have changed resilience and resistance to abrupt or large-scale Hessburg et al. We show examples of multi-level landscape resilience, of feedbacks within and among levels, and how conditions have changed under climatic and management influences. Using evidence from 15 ecoregions, spanning forests from Canada to Mexico, we review the properties of forests that reinforced qualities of resilience and resistance. In fire-maintained forests, resilience to disturbance events arose primarily from vegetation pattern-disturbance process interactions at several levels of organization. Resilience, which encompasses resistance, reflects the amount of disruption an ecosystem can withstand before its structure or organization qualitatively shift to a different basin of attraction. Before the advent of intensive forest management and fire suppression, western North American forests exhibited a naturally occurring resistance and resilience to wildfires and other disturbances.
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