The Establishment of Boreal and Sub-boreal Conifer Plantations: An Integrated Analysis of Environmental Conditions and Seedling Growth

Abstract

Abstract Data from similar field experiments located in the Great Lakes-St. Lawrence, Boreal, and Sub-boreal spruce regions of Canada were used to study relationships among factors such as environmental conditions, seedling growth and survival, and growth analytical yield components. The growth analysis includes both a conventional growth analysis and an integrated analysis of growth and environmental conditions. Survival was best after soil surface modification or weed control. Growth responses were positively related to increases in soil temperature and nutrient availability, and a decrease in vegetative competition. Yield component analysis indicated that Net Assimilation Rate (NAR) was positively related to improved growth. Changes in Specific Leaf Area tended to buffer the effects of changes in NAR on growth, however, and Relative Growth Rate (RGR) responded less to the treatments than did NAR. RGR was related to the availability of light, nitrogen, and soil energy or the efficiency of light, nitrogen, and soil energy use by seedlings on the three sites. As availability of a particular resource improved, growth allocation shifted away from tissues that are used to acquire that resource. Seedlings grew fastest where treatments caused both the availability of a resource and the efficiency (growth/unit resource) of its use to increase. The analytical framework proposed has application in studying the responses of trees to environmental changes and in determining factors that limit tree growth. For. Sci 37(1):68-100.