Factors Influencing the Spatial and Temporal Dynamics of Engelmann Spruce Mortality during a Spruce Beetle Outbreak on the Markagunt Plateau, Utah
Abstract:Host conditions are known to influence spruce beetle population levels, but whether they influence the spatial and temporal patterns of beetle-caused mortality during an outbreak is unknown. Using dendrochronological techniques, we quantified the spatiotemporal dynamics of a modern (late 1980s through the early 2000s) spruce beetle outbreak in Engelmann spruce on the Markagunt Plateau, Utah. Erupting beetle populations occurred in multiple areas across the Plateau over the course of ∼8 years. Early in the outbreak, the timing of spruce mortality was strongly and predictably related to latitude, slope, aspect, stand structure, host species composition, and site productivity potential. Exogenous forcing from landscape-scale drivers such as winter minimum temperatures, summer maximum temperatures, and landscape-wide host suitability probably contributed to spruce beetle population success and heightened spruce mortality. As the outbreak progressed, the timing of spruce mortality became less well correlated to stand and environmental variables. The outbreak subsided when suitable host material was depleted, including smaller spruce in remote stands at the fringe of the spruce-fir zone. Tests for spatial and temporal autocorrelation of beetle-cased spruce mortality did not provide strong evidence for the common perception that spruce beetle outbreaks originate in a specific location (epicenter) and then “spread” across the landscape; rather, support for positive spatial synchrony of multiple, building populations during development of the outbreak was found. Based on these results, silvicultural intervention before the onset of an outbreak might mitigate Engelmann spruce losses; however, the same is almost certainly not true later in an outbreak of this scale and magnitude.
Document Type: Research Article
Publication date: February 1, 2012
More about this publication?
- Forest Science is a peer-reviewed journal publishing fundamental and applied research that explores all aspects of natural and social sciences as they apply to the function and management of the forested ecosystems of the world. Topics include silviculture, forest management, biometrics, economics, entomology & pathology, fire & fuels management, forest ecology, genetics & tree improvement, geospatial technologies, harvesting & utilization, landscape ecology, operations research, forest policy, physiology, recreation, social sciences, soils & hydrology, and wildlife management.
Forest Science is published bimonthly in February, April, June, August, October, and December.
2015 Impact Factor: 1.702
Ranking: 16 of 66 in forestry
Also published by SAF:
Journal of Forestry
Other SAF Publications
- Submit a Paper
- Membership Information
- Author Guidelines
- Ingenta Connect is not responsible for the content or availability of external websites