Seedlings of Gaultheria shallon, Pseudotsuga menziesii, Rhododendron macrophyllum and Tsuga heterophylla were grown together in the greenhouse in soils from three young managed Douglas-fir forests in the Oregon Coast Range. The main objectives were 1 )to evaluate the ability of ericaceous plants and overstory conifers to share compatible mycorrhizal fungi...
Forest managers of public lands in western Oregon and Washington have become increasingly interested in creating additional conifer cohorts in young, even-aged, second-growth Douglas-fir stands. The purpose of our research was to assess the establishment, survival, and growth of naturally-regenerated and underplanted conifers 10-13 years after overstory thinning and understory...
The amount and quality of competition among
individuals in developing plant communities is an important factor determining community structure, composition and development. In perennial plant communities, this competition is reflected by shifts in carbon allocation among plant parts and can result in long-term structural differences between neighboring individuals. This study...
The growth of western hemlock during the first four
years of seedling establishment was examined in a competitive
environment in which seedlings were exposed to various types
of animal damage and salmonberry and/or alder competition.
The study utilized an existing Nelder/replacement series
experiment which focused on the competitive effects among...
Three studies were conducted to characterize and present early-seral
competition between Douglas-fir seedlings and the surrounding vegetation
communities during Pacific Northwest forest establishment. The first experiment
served as the foundation for this dissertation and was designed to quantify tradeoffs
associated with delaying forest establishment activities by introducing a fallow year...
This publication discusses the environmental requirements of needle diseases, their potential impact on tree vigor, when disease levels signal a problem, and what you can do to minimize damage.