Individual-Based Modeling: Mountain Pine Beetle Seasonal Biology in Response to Climate

Over the past decades, as significant advances were made in the availability and accessibility of computing power, individual-based models (IBM) have become increasingly appealing to ecologists (Grimm 1999). The individual-based modeling approachprovides a convenient framework to incorporate detailed knowledge of individuals and of their interactions within populations (Lomnicki 1999). Variability among individuals is essential to the success of populations that are exposed to changing environments, and because natural selection acts on this variability, it is an essential component of population performance. © Springer International Publishing Switzerland 2015

An Individual Based Model of Mountain Pine Beetle Responses to Climate and Host Resistance

We have developed a model describing the responses of mountain pine beetle to daily fluctuations of temperature, in terms of development, survival and reproduction. The model also describes the aggregation, attack, and competition of beetles in pine stands. Built in an individual based framework, using an object-oriented approach, this model can predict the response of beetle populations to climatic conditions and host plant resistance and distribution, at the stand level. We are using this model to better understand the interaction between climate and host plant resistance that determine population growth rates in various environments. We will focus on the contrasting population performance of MPB on whitebark pine compared to lodgepole pine

Effect of Climate Change on Range Expansion by the Mountain Pine Beetle in British Columbia

The current latitudinal and elevational range of mountain pine beetle is not limited by available hosts. Instead, its potential to expand north and east has been restricted by climatic conditions unfavorable for brood development. We combined a model of the impact of climatic conditions on the establishment and persistence of mountain pine beetle populations with a spatially explicit, climate-driven simulation tool. Historic weather records were used to produce maps of the distribution of past climatically suitable habitats for mountain pine beetles in British Columbia. Overlays of annual mountain pine beetle occurrence on these maps were used to determine if the beetle has expanded its range in recent years due to changing climate. An examination of the distribution of climatically suitable habitats in 10-year increments derived from climate normals (1921-1950 to 1971-2000) clearly shows and increase in the range of benign habitats. Furthermore, an increase (at an increasing rate) in the number of infestations since 1970 in formally climatically unsuitable habitats indicates that mountain pine beetle populations have expanded into these new areas. Given the rapid colonization by mountain pine beetles of former climatically unsuitable areas during the last several decades, continued warming in western North America associated with climate change will allow the beetle to further expand its range northward, eastward and toward higher elevations