Executive Summary

The St. Louis metropolitan area has grown outward from the central city constantly as have most larger urban areas in the United States. Often times with outward expansion come environmental and political concerns. One concern has been in regard to trees and the effect residential development has had on tree growth. Trees are beneficial in residential areas because they provide shade from the sun, shelter from the wind, habitat for animals, put oxygen in the air, help prevent erosion and enhance property values. The information in this report can help us understand the changes and effect residential development has had on tree coverage.

The purpose of this project was to determine the effect of residential development on overall tree canopy cover. The project used state-of-the art technology to compare the tree canopy cover from two time periods about 30 years apart. Aerial photographs from the time periods were acquired and referenced to real-world coordinate so that accurate measurements could be performed using geographic information system technology. Tree canopy from each time periods was then delineated. The areas of tree canopy from the two time periods were then overlaid to determine the following:

· areas that did not have tree canopy in both time periods,
· areas that lost tree canopy cover,
· areas that gained new tree canopy cover, and
· areas that have tree canopy cover in both time periods.

This study concerned itself only with tree canopy cover and not changes in specific tree species. After a discussion on the methodology used in this study, the results are presented in a series of tables and maps along with an interpretation of the findings.