Modeling the Impact of SO sub 2 Pollution on the Community Structure and Succession in a Coniferous Forest of the Western USA

摘要

A model is being developed to project the future impact of SO sub 2 pollution on western USA forests. For a case study, the model is being applied to the Ponderosa pine (Pinus ponderosa) and mixed conifer forests of the Sierra Nevada mountains of California, USA. The associated species in these forests are Abies concolor (White fir), Pseudotsuga menziesii (Douglas-fir), Pinus lambertiana (sugar pine), Libocedrus decurrens (incense-cedar), Quercus kelloggii (California black oak), and Pinus jeffreyi (Jeffrey pine). The model is based on JABOWA a simulator of forests of the northeastern USA. For use in western forests, extensive modifications are needed in JABOWA in temporal seed-crop patterns and by introducing fire ecology and moisture stress on vegetation. The model establishes individual seedlings, grows them individually, and simulates mortality of each one. A structure chart of the succession model is given. The effects of SO sub 2 on growth rate on Ponderosa pine, white fir, and Douglas fir are plotted. (ERA citation 05:027923)