There are an estimated 400 000-550 000 km of unpaved resource roads in British Columbia. These roads are used for forest, mineral, and energy development, commercial and public recreation, and in some cases for access to private land holdings. This literature summary lists road effects on terrestrial and aquatic wildlife, plant communities, and physical elements found across landscapes in British Columbia. These effects may be local or may apply to large areas. Road effects can occur during construction or with subsequent road presence, upkeep, and use. Also summarized are recommendations meant to reduce negative road effects. These include taking a strategic approach to road and access management, using structured road planning methods and tools, implementing mitigation techniques, and following up with effectiveness monitoring and reporting. The summary also provides recommendations for further studies of road effects.

Outbreaks of mountain pine beetle are evaluated as a generic disturbance agent, and comparisons are made with other forest disturbances such as wildfire, windthrow, and logging. A useful basis for comparison is the degree of disruption to the overstorey, understorey, and forest floor layers. Clear differences are observed in the impacts of bark beetles, fire, and windthrow, but there is overlap with various harvesting systems. Insects are selective in terms of the species or size of tree that is killed; this selectivity varies with stand composition, stand structure, and outbreak stage. The mountain pine beetle functions as part of larger natural disturbance regimes in western North America, which vary with climate and forest type. Outbreaks of many different insects occur throughout western Canada, with the relative role of fire and insects differing among ecoregions and over time. Beetle-killed stands may facilitate extreme fire behaviour and may be more susceptible to future burning. Large expanses of dead or removed trees also result in altered soil water balance and stream flows, disposing some sites to mass movement or flooding. All disturbances generate heterogeneity, with much of the value to biodiversity and ecosystem recovery depending on residual structure and biological legacies. The capacity for unassisted recovery and the value of each stand to timber supply, carbon balance, and habitat needs in a landscape context are relevant when considering salvage logging or forest rehabilitation. The future role of forest pests is expected to fluctuate in response to changes in climate and the altered composition and structure of western forests.

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