Forests as carbon sinks--benefits and consequences

Abstract

With their ratification of the Kyoto Protocol, many countries have established forests on previously non-forested land with the view of offsetting greenhouse gas emissions. While these forests indisputably result in increased carbon storage in above-ground biomass, consideration of other major implications is often neglected. Forest establishment results in changes in albedo and soil carbon storage, reduced runoff and downstream water supply, and effects on biodiversity. Such effects of forest establishment may be less desirable from environmental, economic and social perspectives. While there have been many studies of the impacts of forest establishment on individual aspects, policy makers need to be able to integrate the benefits and consequences to assist in making decisions on land management. Further, the relative magnitude of the effects of forestry needs to be considered in the context of elevated atmospheric carbon dioxide partial pressure and climate change resulting in increasing temperature and changes in the amount and distribution of rainfall. This introductory review highlights the major benefits and consequences of forest establishment and demonstrates progress in integrating across the services provided by forests. New modelling approaches are being developed that allow analysis of benefits, consequences and trade-offs to assist policy makers in decisions to manage the provision of multiple resources.