Large scale biotic damage impacts on forest ecosystem services

ABSTRACT

Insect outbreaks are natural phenomena that play a critical role in the development, senescence, and rebirth of forests. However, the damage caused by large-scale epidemics can have landscape scale consequences that are often poorly understood. The recent mountain pine beetle (MPB) outbreak in Canada has impacted a record >18.5 million hectares of pine forests, placing forest values at risk and significantly impacting forest-dependent communities within the region. To assess this impact, an ecosystem service-based approach was applied. Based on land cover information and monitoring data, four ecosystem services were assessed and mapped: merchantable timber, water provisioning, aboveground carbon storage, and vegetation diversity (supporting habitat). Timber is the most impacted provisioning ecosystem service followed by water provisioning, with peak stream flow in affected watersheds being positively related to mortality percent. Effects on carbon storage are substantial, with 20% of total timber aboveground carbon in dead pine trees. These effects may be mitigated, however, by the growth response of residual live trees and forest regeneration. The potential vegetation diversity showed a positive response to MPB-caused tree mortality. The results of our study may help with setting management priorities in response to large-scale biotic damage in forests in British Columbia and elsewhere.

KEYWORDS:

• Ecosystem function
• ecosystem services map
• forest damage
• outbreaks and epidemics
• provisioning services
• regulating services
• spatial distribution

Acknowledgments

This research was supported by the Natural Science and Engineering Research Council of Canada (grant no. NET GP 434810-12) to the TRIA Network, with contributions from Alberta Agriculture and Forestry, Foothills Research Institute, Manitoba Conservation and Water Stewardship, Natural Resources Canada–Canadian Forest Service, Northwest Territories Environment and Natural Resources, Ontario Ministry of Natural Resources and Forestry, Saskatchewan Ministry of Environment, West Fraser and Weyerhaeuser. We are also thankful to British Columbia Ministry of Forest, Land, Natural, Resources and Operation for providing Vegetation resources Inventory Data (VRI), Canada Forest Service for Climate Data and Environment Canada for Water flow data. We also thankful to the two anonymous reviewers for their constructive suggestions that greatly improved the overall manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Amalesh Dhar http://orcid.org/0000-0001-8357-826X

Additional information

Funding

This work was supported by The Natural Science and Engineering Research Council of Canada [grant number NET GP 434810-12].