Theses and Dissertations Collection

Tree-ring sub-annual growth parameters provide robust, annually resolved climate proxy data, which is critical for the creation of paleoclimate reconstructions used for contextualizing current climatic change. However, the relationships between tree-ring growth parameters and climate variables varies greatly among tree species and stand locations, necessitating research which closely studies those relationships, and their implications for regional ecology and the creation of paleoclimate reconstructions. This research aimed to investigate further the suitability of mountain hemlock (Tsuga mertensiana (Bong.) Carr.) for blue intensity (BI) analysis, and additionally investigate the relationships between climate and tree-ring growth parameters of a low-elevation, Northern Idaho mountain hemlock stand, and whether these relationships are consistent through time. In this study, ring width and BI tree-ring growth parameters are analyzed, resulting in the successful creation of a total of six chronologies; total ring width (TRW), earlywood width (EWW), latewood width (LWW), earlywood blue intensity (EWB), latewood blue intensity (LWB), and delta blue intensity (ΔBI), additionally, the most significant temperature-proxy relationships and seasonality for each parameter were identified. The identified temperature-proxy relationships were significant for all parameters with the exception of EWB, which had the most variable correlation values over time. Early spring season temperatures had the greatest correlations among the majority of proxies with the exception of ΔB, which benefitted from a more extended seasonality. The strength of spring temperature signals in the chronologies created in this study have the potential for future applications for spring temperature reconstructions, which would be relevant because of the impacts of springtime warming on local phenology and hydrology.