Rates of Tree Growth and Forest Succession in the Anchorage-Matanuska Valley Area

Abstract

In the course of drawing up a forest-cover map, data were collected on forest types and their distribution, and rates of growth. It was concluded that soil type and superficial geology are relatively unimportant in controlling distribution of vegetation in the area, as compared with occurrence of fires and availability of seed immediately after a fire. Growth rate is controlled by the amount of sunlight and the drainage characteristics of the site. Cottonwood and Aspen had the highest growth rates observed. Drainage conditions apparently affect the growth of White Spruce more than that of Birch. Black Spruce had the lowest growth rate. In the area studied, a mixed Birch/White Spruce forest is generally self-perpetuating. Only in small areas have pure White Spruce stands developed from this association