Some Questions Relating to the Age Dynamics of Boreal Forests

This manuscript is a result of discussions prior to and during the workshops "Impacts of Change In Climate and Atmospheric Chemistry on Northern Forest Ecosystems and Their Boundaries" (August 1987) and "Global Vegetation Change" (April 1988) and is an initial step in the development of a synthesis between realistic (e.g. biological-detail-rich) computer oriented models of forest and more mathematically, tractable, but simpler forest models. The work is focused on the boreal forests of the world (an important carbon reservoir and an important reserve of softwood timber). The boreal forests are also potentially strong impact systems under current scenarios of CO2-induced climate warming. One purpose of building a model is to get an understanding of what may happen to the climate if, for example, all of the boreal belt were to disappear, or if its functional efficiency were to double. Could such a disappearance occur simultaneously with changes in the tropical forests? How would this change the exchange between atmosphere and the earth surface? The authors try to describe a forest (or vegetation as a whole) as a boundary layer between fast atmospheric processes and slow processes in soil and underground water systems, and consider the geometry of canopies and roots as a function of extremes corresponding to a stable equilibrium of soil and underground water systems. The authors hope to consider these and similar problems during their continuing cooperation