Radial growth responses in lodgepole pine
The Bioclimatic Envelope Model (BEM) forecasts dramatic changes in the latitudinal and elevational distributions of the climatic envelopes of forest trees throughout British Columbia over the next eight decades. While BEMs provide tremendously valuable information regarding potential future range distributions, field studies are needed to determine the actual biological responses of forests to changes in climate. Sierra Curtis-McLane’s research evaluated predictions from British Columbia BEMs compared to germination, survival and fitness of conifers planted outside of their native climatic ranges. Her research examined how climate patterns affect annual growth in populations of lodgepole pine (Pinus contorta). While baseline growth differential data have confirmed strong genotype by environment interactions, our research addressed the question of how annual ring widths vary among populations within a site and among sites for a given population. Wood cores were sampled in sixteen lodgepole pine common gardens that were established in 1974. Annual growth trends were analyzed in conjunction with weather data, thereby shedding light on fitness responses of varying genotypes to current climate trends. The universal response function (URF) approach developed by CFCG member Tongli Wang was used to analyze results. In general, the analysis revealed similar growth patterns and climatic relationships of provenances for annual tree rings as had been documented earlier for cumulative tree growth in the same provenance trial, confirming the results of Wang et al. (2010).