Population Level Models of Forest Dynamics

This paper outlines several general aspects of modeling forest dynamics. First we describe forest dynamics at the population level, based upon the results of certain dynamical equations. Second we consider above-ground plant species such as grasses and mosses, which are most important for boreal forests since they provide the boundary conditions for tree generations. Modeling creativity in this field is very limited, compared with tree systems, and is in reality more an art than science in view of its specific nature. Several examples in this direction are shown

Periodic Behavior of an Age-Distributed Population of Trees

In this paper, the age dynamics of a population of trees and a particular case of age dynamics are studied. The method used in the investigation pertains to the formulation of corresponding dynamic models. Following the description of the object and an examination of modeling options, a number of simplified, analytically-studied models are presented, followed by a more realistic, quantitative model of an age distributed population system with periodic behavior

A Regional Model of Long-Term Wetland-Forest Dynamics

Wetland-forest dynamics is a subject of great theoretical and practical interest, particularly with respect to the boreal forest in the USSR. Scandinavia and Canada. Under current hydrological conditions, the characteristic time for succession from forest to bog (or vice versa) is about 100 years. But with greenhouse-gas warming of the atmosphere during the next 50 years, succession rates may be considerably altered, and this might have significant impact on the forest sector. It is therefore essential that models be developed and tested with historical data, so that an idea may be obtained of likely future states. This Working Paper is a significant contribution to the literature on wetland-forest dynamics

Model of the Optimal Development of a Plant Taking Into Account Defence and Competition

This paper presents a very simple model of the development of a species, taking into account the energy expended on growth and on competition. Using probability distributions on growth rates and population densities, some very general results are obtained. The model predictions of course need to be tested with field data, and this may provide a conceptual framework for new measurement programs

The Silvics of Some East European and Siberian Boreal Forest Tree Species

In recent years, the boreal forest has received increased scientific attention in light of projected climatic warming to boreal regions from increased concentrations of atmospheric carbon dioxide. The ecological consequences of such a warming could be significant. However, before the consequences of climatic change can be properly investigated, the ecology of boreal forest tree species must be adequately understood. Though the life-histories of many North American boreal forest tree species are well known, little comparable information has been compiled in English for the major boreal forest tree species of the Soviet Union. In this paper, we present a preliminary description of the silvics of seven of these species -- their ranges, optimum climatic and soil conditions, regeneration characteristics, tree growth features, responses to suboptimal site conditions, and reaction to fire. We hope that this information will provide a useful data base for use in modeling the ecology of these species