Impacts of climate warming on forests in Ontario: Options for adaptation and mitigation

Abstract

This paper summarizes current knowledge about the optical properties of greenhouse gases and general climate-warming influences. It explains the influence of this new phenomenon on the major ecosystems of the world, and considers the process of deforestation. It then analyzes the warming trends in Ontario based on data from two weather stations with continuous records of more than 120 years, to determine the rate of warming in the Great Lakes-St. Lawrence Region. The results indicate a temperature increase of about 0.76 °C per century and an 8% increase in annual total precipitation.Current climate change models indicate that for a scenario of 2 × CO₂ levels some general, probable prognoses can be made, including a temperature increase of up to 4.5 °C, which might be disastrous for existing forest ecosystems. Specifically, the consequences of climate warming on (a) northward shifts of ecological conditions, (b) forest productivity, and (c) forest physiology and health, are examined. In the context of global warming, the paper then recommends practical management measures necessary to ensure adaptation of existing forest ecosystems to the warming that is already developing. These measures are intended to provide a no-risk environment for existing forests until rotation age. Next, a wide range of mitigative measures is examined with a view to securing the long-term preservation of forest ecosystems to avoid major ecological disruptions and, gradually, to reverse climate warming. Application of these measures requires international consensus, but countries that apply these recommendations first have a chance to profit from them due to the "CO₂ fertilization" effect. Key words: climate change, silviculture, forest management