Document Type
Article
Journal/Book Title/Conference
Forests
Volume
12
Issue
6
Publisher
MDPI AG
Publication Date
7-17-2021
Award Number
Minnesota Agricultural Experiment Station MIN-42-068
Funder
Minnesota Agricultural Experiment Station
Utah Agricultural Experiment Station
First Page
1
Last Page
18
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Abstract
Bark beetle (Dendroctonus spp.) outbreaks in the middle latitudes of western North America cause large amounts of tree mortality, outstripping wildfire by an order of magnitude. While temperatures play an important, and direct role in the population dynamics of ectothermic bark beetles, an equally important influence is the nature of the host substrate—the structure and composition of forested communities. For many of the dominant tree species in the western United States, “hazard” indices have been developed for specific bark beetles, which generally include three key variables—host tree size, absolute or relative density of the stand, and percentage of host composition. We provide a conceptual model to apply these three variables across forest ecosystems and bark beetles that shifts the thinking from a species–specific model to a model which focuses on the underlying ecological factors related to bark beetle outbreak susceptibility. We explored the use of our model across multiple scales using the Forest Inventory and Analysis database: Interior West, USA; the states of Colorado and Arizona; and specific national forests within Arizona that are implementing a large-scale restoration effort. We demonstrated that across the Interior West and Colorado, the vast majority of forests have moderate to high susceptibility to bark beetles. Our conceptual model maintains the simplicity of previous “hazard” models but acknowledges the need to consider scale when managing bark beetles. It also shifts the management approach from resistance thinking to the development of “associational resilience”, where the focus is not on any one individual stand or area but the longer-term perspective of forest persistence across the landscape.
Recommended Citation
Windmuller-Campione, M., R.J. DeRose, and J.N. Long. 2021. Landscape-scale drivers of resistance and resilience to bark beetles: a conceptual susceptibility model. Forests 12(6):798.
