Pests/Biota

Mountain Pine Beetle

Threats to forests may come in the form of both native and exotic biota. Several bark beetle species, mostly in the family Curculionidae, subfamily Scolytinae, have the potential for dramatic population increases under favorable forest and climate conditions, which can result in landscape-scale mortality to the host tree species, (e.g., Wood and Unger 1996). For example, the mountain pine beetle (Dendroctonus ponderosae Hopk.) has killed much of the mature lodgepole pine (Pinus contorta Dougl. ex. Loud.) over an area of approximately 9 million hectares (ha) in British Columbia in recent years (Westfall 2005). Events such as these have widespread implications for current and future forest management, ranging from effects on timber supply and operations, wildfire-urban interface, wildlife habitat, and aesthetics.

Biotic threats often work in concert with other forests threats, such as fire or severe weather threats, causing patterns of devastation. In this section, native pests, such as bark beetles, and nonnative exotic pests, such as gypsy moths, are discussed in terms of stages of invasion and decision-making in management. A focus on human-mediated pathways is considered as a means of dispersion.

To further review results of biotic threats, consider reading the following Environmental Threats Case Studies:

Assessing Insect-Induced Tree Mortality across Large Areas with High-Resolution Aerial Photography in a Multistage Sample

A Multicriteria Framework for Producing Local, Regional, and National Insect and Disease Risk Maps

Risk Analysis and Guidelines for Harvest Activities in Wisconsin Oak Timberlands to Minimize Oak Wilt Threat

Assessment of Oak Wilt Threat to Habitat of the Golden-Cheeked Warbler, an Endangered Species, in Central Texas

Probabilistic Risk Models for Multiple Disturbances: An Example of Forest Insects and Wildfires