Spatiotemporal mapping of potential mountain pine beetle emergence – Is a heating cycle a valid surrogate for potential beetle emergence?

Abstract

The mountain pine beetle emergence is temperature dependent. We hypothesize that heating cycles defined and determined by summer (July and August) daily temperature series represent reliable windows for potential beetle emergence. In this study, we first downscaled two coarse resolution meteorological datasets (the North American Regional Reanalysis data and provincial gridded climate data) using an elevation correction approach. We mapped heating cycles spatially and temporally across the province using the maximum daily temperatures derived from the downscaled meteorological data. The mean absolute errors (MAEs) and mean bias errors (MBEs) in the downscaled maximum daily temperature based on 30 weather stations reveal that the elevation-based downscaling approach is effective and the average errors do not significantly affect the spatial and temporal patterns of heating cycles in terms of the four key variables and frequency distributions of heating cycles. The temporal patterns of heating cycles for most of the monitoring years sufficiently capture the major emergence peaks observed at 16 monitoring sites. Therefore, the hypothesis above is valid and potential beetle emergence can be spatially and temporally mapped using heating cycles at the landscape scale.