Climate Change Impacts on Forest Growth and Tree Mortality: A Data-Driven Modeling Study in the Mixed-Conifer Forest of the Sierra Nevada, Calafornia

Impacts of climate change on the productivity and health of a forest in the mixed-conifer region in California are assessed. Four climate scenarios show a distinct link between increasing summer temperatures and stem volume growth declines. The relative impact of climate change is greater for white fir, incense-cedar, and Douglas-fir compared to ponderosa pine and sugar pine. Higher summer temperatures in a Mediterranean climate can induce greater tree water stress through higher evapotranspiration rates and/or faster depletion of moisture in the soil profile. Significant increases are found in gross primary productivity for poplar coppice plantations grown for three years in CO sub(2) enriched environment. Results from a web-study in a mature natural forest show no persistent stimulation in tree stem growth.