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The potential for mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae: Scolytinae), to expand its historical range in North America from west of the continental divide into the eastern boreal forest was assessed on the basis of analyses of the effects of climate and weather on brood development and survival, and key aspects of the interaction of mountain pine beetle with its hosts and associated organisms. Variation in climate suitability and high host susceptibility in the boreal forest create a finite risk of establishment and local persistence of low-level mountain pine beetle populations outside their historical range. Eventually, these populations could become widespread and cause epidemic infestations, creating an ecological pathway eastward through the boreal forest. Such infestations would reduce the commercial value of forests and impose an additional disturbance on native ecological systems.

Forest insects and pathogens are the most pervasive and important agents of disturbance in North American forests, affecting an area almost 50 times larger than fire and with an economic impact nearly five times as great. The same attributes that result in an insect herbivore being termed a "pest" predispose it to disruption by climate change, particularly global warming. Although many pest species have co-evolved relationships with forest hosts that may or may not be harmful over the long term, the effects on these relationships may have disastrous consequences. We consider both the data and models necessary to evaluate the impacts of climate change, as well as the assessments that have been made to date. The results indicate that all aspects of insect outbreak behavior will intensify as the climate warms. This reinforces the need for more detailed monitoring and evaluations as climatic events unfold. Luckily, we are well placed to make rapid progress, using software tools, databases, and the models that are already available.

No abstract

Forest insects and pathogens are the most pervasive and important agents of disturbance in North American forests, affecting an area almost 50 times larger than fire and with an economic impact nearly five times as great. The same attributes that result in an insect herbivore being termed a "pest" predispose it to disruption by climate change, particularly global warming. Although many pest species have co-evolved relationships with forest hosts that may or may not be harmful over the long term, the effects on these relationships may have disastrous consequences. We consider both the data and models necessary to evaluate the impacts of climate change, as well as the assessments that have been made to date. The results indicate that all aspects of insect outbreak behavior will intensify as the climate warms. This reinforces the need for more detailed monitoring and evaluations as climatic events unfold. Luckily, we are well placed to make rapid progress, using software tools, databases, and the models that are already available.

Phenology is a key aspect of plant and animal life strategies that determines the ability to capture seasonally variable resources. It defines the season and duration of growth and reproduction and paces ecological interactions and ecosystem functions. Phenology models have become a key component of models in agronomy, forestry, ecology, and biogeosciences. Plant and animal process-based phenology models have taken different paths that have so far not crossed. Yet, they share many features because plant and animal annual cycles also share many characteristics, from their stepwise progression, including a resting period, to their dependence on similar environmental factors. We review the strengths and shortcomings of these models and the divergences in modeling approaches for plants and animals, which are mostly due to specificities of the questions they tackle. Finally, we discuss the most promising avenues and the challenges phenology modeling needs to address in the upcoming years.

Much evidence is accumulating that insect distributions are changing. The changing earth's climate is providing mobile species with an evolving ''hospitability'' template, and increasing global commerce expands opportunities for mobile species to colonize new habitats. Predicting the distribution of insects in the face of accelerating global commerce and climate change is quite a challenge. Many fruitful approaches are available and are being improved. Some are correlative; some are based on process-level knowledge. We have focused on an eco-physiological approach based on the known responses of species to specific weather factors at the physiological level. Of particular importance are developmental responses, of course, as they determine climates under which an insect can achieve a stable, adaptive seasonality. With this underlying minimal requirement, models can also take into account other weather influences such as cold tolerance and the deleterious effects of too much heat. In this paper, we illustrated the use of this approach to predict the change of distribution and potential impacts of the spruce budworm Choristoneura fumiferana (Clem.), a major native insect pest of conifer forests in North America. Like previous work on the invasive gypsy moth (Lymantria dispar L.) and the native mountain pine beetle (Dendroctonus ponderosae Hopkins), the present work points to the following conclusions concerning the effects of global warming on species distributions: (1) they will shift towards the poles (and to higher elevations); (2) temperate regions will bear the brunt of these shifts; and (3) distribution shifts may be good or bad, depending on the species and the regions concerned.

No abstract