Despite the critical ecological roles of structural features in forests, ecologically
relevant quantitative measures of structure that allow comparisons among forest stands
are still limited. A new index, the structural complexity index (SCI), was developed to
characterize and compare the structural complexity of different forests. Point patterns
of stem-mapped trees...
Although there has been extensive research on the geomorphic and ecologic role of
large woody debris (LWD) in streams, the dynamics of LWD in streams are poorly
known due to various measurement difficulties during floods. In this thesis I present the
results of two flume experiments on the dynamics of...
A three-year investigation was conducted during 1980-1982 to
evaluate the potential of using herded sheep as a silvicultural tool
to suppress brush in Douglas-fir (Pseudotsuga menziesii) plantations
of Oregon's Coast Range. Sheep browsing of Douglas-fir was highest
in May soon after bud break. Averaged over the 2 years of grazing,...
Nitrogen, phosphorus and sulfur concentrations were measured in the soil, foliage and litter of Douglas-fir growing in pure Douglas-fir and mixed conifer stands. On four sites of contrasting fertility and climatic conditions, plots had been modified by the introduction of alder, thinning, or by a single application of nitrogen fertilizer...
A greenhouse bioassay was used to investigate effects of natural and manmade disturbances on native ectomycorrhizal populations of Douglas-fir and western hemlock on a steep southeast slope in the
west central Cascade Mountains. Total and mycorrhizal root tips were counted on seedlings grown in soils collected from (a) two 100+...
Research activities in the post-IBP phase of the Biome program prior to July 1975 were reported in Internal Report 162. Summaries of research and synthesis activities from July 1975 to August 1976 are presented here. The reports are arranged in the following order: Analysis of individual terrestrial ecosystems, which has...
The specific objectives of the program are: (1) To understand the relative behavior of terrestrial and aquatic ecosystems in various environments in the biome. (2) To develop conceptual and computer simulation models that describe nutrient, carbon, and waterflows on a short-term basis (fewer than ten years) and which integrate research...
The initial distribution of organic arsenical silvicides was
measured in the trees, litter and soil of four forest types in the
Pacific Northwest following a standard, precommercial chemical
thinnning. Factors which influenced the persistence, movement or
fate of these compounds were noted and used to evaluate differences
in the generalized...
Respiratory rates were measured, in situ, for the litter, the
soil, and the litter-soil subsystems of a Pseudotsuga menziesii forest
as a function of type of understory vegetation. The major objectives
were to demonstrate the utility of the litter layer as a distinct subsystem
of this forest ecosystem, to demonstrate...