Responses and modeling of southern pine beetle and its host pines to climate change

Abstract Southern pine beetle (Dendroctonus frontalis Zimmermann) is widely regarded as one of the most destructive native pest insects in North and Central America. It is also one of the most studied, with a century long history of research. In this chapter, we review the potential impacts of climate change on southern pine beetle’s distribution, its associated fungi and arthropods, and its host trees. Further, we review past and present modeling efforts with regard to outbreak dynamics and climate change, including directions for future modeling. Our review indicates that southern pine beetle is positively affected by temperature with warmer temperatures enhancing their outbreaks and continued northward range expansion. Fungal and arthropod associates are expected to respond variably to climate change, based on their nature of association and respective climatic threshold levels. We expect that southern pine beetle will continue to have abundant host pine resource. However, tree growth and defensive capabilities may vary based on site conditions, genetics, and management, which may affect insect-plant interactions. Approaches to understanding beetle dynamics have mirrored developments in ecological and entomological research during the 20th and 21st centuries, with studies from individual to landscape scales. Modeling efforts aimed at understanding southern pine beetle dynamics under climate change face considerable challenges. Historical time series data collected at local scales and operational intensities provide an invaluable resource but are difficult to incorporate with climate projections calculated at much broader scales. The myriad forms of uncertainty also have yet to be properly identified and handled. Work that addresses drivers across multiple scales and that can successfully partition uncertainty are urgently needed to better understand the population dynamics of southern pine beetle in a rapidly changing world.