Estimation of potential impacts of climate change on growth and yield of temperate tree species

Studies assessing impacts of climate change on forests are numerous, but most evaluate potential tree growth for current and future conditions at discrete time intervals, which is generally insufficient for developing short to medium term forest policies and strategies. Analysis of forest growth and yield during the transition period of climate change is essential in supporting forest management activities in the midst of climate change. A gap model (JABOWA-3) was used to quantify the impact of climate change on major commercial tree species native to Nova Scotia, Canada. Tree species were projected to respond differently to the same level of temperature change. Yields from maples (Acer rubrum and saccharum), beech (Fagus grandifolia), and white pine (Pinus strobus) were projected to increase in response to increasing temperatures; whereas, yields from balsam fir (Abies balsamea), eastern larch (Larix laricina), red spruce (Picea rubens), trembling aspen (Populus tremuloides), and white birch (Betula papyrifera) were projected to decline. Species-specific modifiers of basal area (BA) yield calculated in this study can be used to adjust stand yield predictions. Nine species-specific regression models were developed to facilitate prediction of BA from current conditions as a function of growing degree days increments. Together, yield-modifiers and BA-response models have the potential to help with (1) understanding the climate change patterns of existing yield curves, and (2) development of mitigation and adaptation policies under scenarios of climate changes. This study indicates a general trend of tree-species response to climatic change, and its results should be interpreted with caution taking into account the limitations of model projections.