The Dynamics of Forest Decline

The anthropogenic emissions into the atmosphere have changed the material flows in the system formed by the atmosphere, vegetation, soil, groundwater, and surface waters. The concentrations of several nutrients and toxic compounds are changing. These concentrations are environmental factors and forests are reacting to the changes in the environment. The material flows are analyzed and basic structures to describe the changing concentrations are outlined. Soil acidification is used as an example of changing environmental factors. The photosynthetic and nutritional response of trees is modeled. Aggregated variables are introduced to describe annual effects of environmental change on metabolism of trees. A stand growth model is described in a static environment and necessary modifications in a changing environment are introduced. A more aggregated model to account for the effects of changing environmental factors on forest growth is described