EPA contract 68-03-2442 provided support for three years of the studies to determine the chronic effects of photochemical oxidant air pollutants on a western mixed conifer forest ecosystem. This report deals with the year 1976-77 and is the final publication on EPA contract 68-03-2442. Computer simulation programs have been written for some of the subsections. Subsystems which received greatest attention during this study were: major tree species response to oxidant dose, tree population dynamics, tree growth, moisture dynamics, soil chemical and physical properties, tree mortality relative to disease, insects and other factors, epidemiology of forest tree pathogens with emphasis on Fomes annosus, cone and seed production, tree seedling establishment, litter production and litter decomposition relative to microfloral decomposer populations.

EPA contract 68-03-2442 provided support for three years of the studies to determine the chronic effects of photochemical oxidant air pollutants on a western mixed conifer forest ecosystem. This report deals with the year 1976-77 and is the final publication on EPA contract 68-03-2442. Computer simulation programs have been written for some of the subsections. Subsystems which received greatest attention during this study were: major tree species response to oxidant dose, tree population dynamics, tree growth, moisture dynamics, soil chemical and physical properties, tree mortality relative to disease, insects and other factors, epidemiology of forest tree pathogens with emphasis on Fomes annosus, cone and seed production, tree seedling establishment, litter production and litter decomposition relative to microfloral decomposer populations.

The U.S. Environmental Protection Agency (EPA) was introduced on December 2, 1970 by President Richard Nixon. The agency is charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress. The EPA's struggle to protect health and the environment is seen through each of its official publications. These publications outline new policies, detail problems with enforcing laws, document the need for new legislation, and describe new tactics to use to solve these issues. This collection of publications ranges from historic documents to reports released in the new millennium, and features works like: Bicycle for a Better Environment, Health Effects of Increasing Sulfur Oxides Emissions Draft, and Women and Environmental Health.