Dataset
Data in support of: Mega-disturbances cause rapid decline of mature conifer forest habitat in California
Dryad
09/30/2022
DOI: 10.6078/d1w43v
Abstract
Mature forests provide important wildlife habitat and support critical
ecosystem functions globally. Within the dry conifer forests of the
western United States, past management and fire exclusion have contributed
to forest conditions susceptible to increasingly severe wildfire and
drought. We evaluated declines in conifer forest cover in the southern
Sierra Nevada of California during a decade of record disturbance by using
spatially comprehensive forest structure estimates, wildfire perimeter
data, and the eDaRT forest disturbance tracking algorithm. Primarily due
to the combination of wildfires, drought, and drought-associated beetle
epidemics, 30% of the region’s conifer forest extent transitioned to
non-forest vegetation during 2011-2020. Fifty percent of mature forest
habitat and 85% of high density mature forests either transitioned to
lower density forest or non-forest vegetation types. California spotted
owl Protected Activity Centers (PAC) experienced greater canopy cover
decline (49% of 2011 cover) than non-PAC areas (42% decline). Areas with
high initial canopy cover and without tall trees were most vulnerable to
canopy cover declines, likely explaining the disproportionate declines of
mature forest habitat and within PACs. Drought and beetle attack caused
greater cumulative declines than areas where drought and wildfire
mortality overlapped, and both types of natural disturbance far outpaced
declines attributable to mechanical activities. Drought mortality that
disproportionately affects large conifers is particularly problematic to
mature forest specialist species reliant on large trees. However, patches
of degraded forests within wildfire perimeters were larger with greater
core area than those outside burned areas, and remnant forest habitats
were more fragmented within burned perimeters than those affected by
drought and beetle mortality alone. The percent of mature forest that
survived and potentially benefited from lower severity wildfire increased
over time as the total extent of mature forest declined. These areas
provide some opportunity for improved resilience to future disturbances,
but strategic management interventions are likely also necessary to
mitigate worsening mega-disturbances. Remaining dry mature forest habitat
in California may be susceptible to complete loss in the coming decades
without a rapid transition from a conservation paradigm that attempts to
maintain static conditions to one that manages for sustainable disturbance
dynamics.
Details
- Title: Subtitle
- Data in support of: Mega-disturbances cause rapid decline of mature conifer forest habitat in California
- Creators
- Zachary Steel - University of California, BerkeleyGavin Jones - US Forest ServiceBrandon Collins - University of California, BerkeleyRebecca Green - National Park ServiceAlex Koltunov - US Forest ServiceKathryn Purcell - US Forest ServiceSarah Sawyer - US Forest ServiceMichele Slaton - US Forest ServiceScott Stephens - University of California, BerkeleyPeter Stine - Wildlands NetworkCraig Thompson - US Forest Service
- Resource Type
- Dataset
- DOI
- 10.6078/d1w43v
- Publisher
- Dryad
- Grant note
- 8GG21823 / California Department of Forestry and Fire Protection*
- Language
- English
- Date published
- 09/30/2022
- Academic Unit
- School of Earth, Environment, and Sustainability
- Record Identifier
- 9985222736602771
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