摘要：In the United States and Canada, pine forest ecosystems are being dramatically affected by an unprecedented pine beetle infestation attributed to climate change. Both decreased frequency of extremely cold days and warmer winter temperature averages have led to an enphytotic devastating millions of acres of pine forest. The associated ecosystem disruption has the potential to cause significant health impacts from a range of exposures, including increased runoff and water turbidity, forest fires, and loss of ecosystem services. We review direct and indirect health impacts and possible prevention strategies. The pine beetle infestation highlights the need for public health to adopt an ecological, systems-oriented view to anticipate the full range of potential health impacts from climate change and facilitate effective planned adaptation. Globally, there is abundant evidence of accelerating ecosystem disruption associated with climate change. 1 Many of these disruptions are likely to have significant direct and indirect health effects through a variety of overlapping pathways. 2–4 Ecosystem changes can affect human health both directly and indirectly, from shifts in disease vector range and behavior to loss of ecosystem services. The current climate-driven pine beetle infestation of North America serves as a key example, although its health impacts have been little studied. Predators of mountain pine beetles play a limited role in reducing pine beetle populations, and historically, temperatures have been the largest contributor to mortality. 5 In recent years, unusually high proportions of beetle larvae have survived over the winter, resulting in a devastating epiphytotic in North American pine forests 6 that is expected to continue and expand during the next century. 7 This is in sharp contrast to previous, smaller outbreaks, which were halted by temperature fluctuations and human interventions, such as stand thinning and insecticide application. 8–10 As a result of these new dynamics, what were once sporadic epiphytotics are becoming a large enphytotic, with periodic epiphytotics expanding beyond the beetle’s northern range. (For specialized terms used in this article, see box on the next page.) With its unprecedented scale, the current infestation is believed to have diminished a range of ecosystem services provided by pine forests and may increase the risk of several direct health effects resulting from increased runoff, surface water turbidity, and forest fires, along with their associated waterborne disease and respiratory disease impacts. Glossary of Specialized Terms Term Definition Enphytotic A plant disease that persists in a plant population over a given period of time, similar to endemic disease in human populations. Epiphytotic Epidemic plant disease where the pathogen suddenly and rapidly affects many plants in a specific area, similar to epidemic disease in human populations. Ecosystem services The benefits to humankind from processes and natural resources that are supplied by natural ecosystems. Annex I Country An industrialized country and an economy in transition as classified by the United Nations Framework Convention on Climate Change. Open in a separate window We explore the potential human health impacts of the current pine beetle infestation and apply a public health framework to identify interventions that may reduce future impacts.
