This report is one of a series issued in cooperation with the Army-Navy-Civil Committee on Aircraft Design Criteria under the supervision of the Aeronautical Board. Information reviewed and reaffirmed 1956.
Using existing data from untreated research plots, we developed equations
for predicting 5-yr diameter-growth rate (ΔD₅), 5-yr height-growth
rate (ΔH₅), and 5-yr mortality rate (PM₅) for Douglas-fir [Pseudotsuga
menziesii (Mirb.) Franco] in the coastal region of the Pacific Northwest.
These equations are revisions of the equations constructed in 1995–1997
for...
A method is described to determine the distribution of the bending stresses in a wood beam when some of these stresses exceed the proportional limit. This is used to calculate the position of the neutral axis and the bending strength of some Douglas-fir beams. The calculated values agreed with the...
Diameter growth of Douglas-fir (Pseudotsuqa menziesii (Mirb.) Franco) estimated from increment cores was compared with that obtained from repeated measurements of tree diameter on permanent plots located in two Douglas-fir study areas in the central Coast Range of Oregon. Growth was measured for a 6-year period (1979-
1985). Diameter growth...
A review is made of methods which assess the bias
and non-normality of parameter estimates and predictions
obtained with nonlinear regression. Particular emphasis
is placed upon curvature measures of nonlinearity,
related measures of parameter and prediction bias, and
the effects of reparameterizations. Alternate models of
individual tree height growth are...
A branch mortality dating technique and whorl
sampling strategy were implemented to model five-year
crown recession from data collected on temporary
plots. Twenty-eight Douglas-fir from two levels-of-growing-
stock studies in Oregon and Washington were
first dissected to validate the proposed dating
technique and assess alternative sampling strategies.
Branch mortalities in...
The objective of this study was to assess the effects of
forest management intensity on long-term productivity of Pacific
Northwest Douglas-fir forests. The components of management intensity
included rotation length, timber utilization standard (whole
tree or bole only), method of slash treatment (remove/burn or leave)
and fertilization practice (urea nitrogen...
Forest growth and yield models are critical to supporting decision making in forestry, but often lack considerations for wood properties. The feasibility of simulating wood properties in the context of a Douglas-fir individual tree growth and yield model was evaluated. This assessment explored the effect of predicted sapwood width, stem...
Crown profile was modeled using a system of equations with three components.
The first equation predicts the maximum crown width of an open grown tree based on
the tree's diameter at breast height. The second equation modifies maximum crown
width to represent the largest width of the crown in stand...
Equations for predicting height growth, basal area
growth and diameter inside bark are presented for
Douglas-fir. Basal area growth equations for grand fir
are also presented. The growth models were developed
for use in an individual tree/distance independent
growth simulator. Various model forms and measures of
competitive stress were compared...
Equations for predicting diameter growth are an essential component of single-tree growth and yield models (Munro 1974). Diameter
growth predictions are used to characterize individual-tree development and to project the growth of stand basal area and volume. Both diameter growth and basal area growth have been used as the dependent...
Forest growth models in the Pacific Northwest are predominantly empirical. Predictions of yield under alternative silvicultural regimes cannot rely completely on field trials; yet empirical growth models are often inadequate for extrapolating untested regimes and genotypes. The limitations of current models include (1) long time-steps (e.g. 5-10 years); (2) insufficient...
Using existing permanent research plot data, we developed equations for predicting height-to-crown-base (HCB), 5-yr diametergrowth rate (delta D), 5-yr height-growth rate (delta H), 5-yr mortality rate (PM), and the maximum size-density trajectory for Douglasfir and western hemlock in the coastal region of the Pacific Northwest. With the exception of the...
There has been an increased interest in the
quantification of pattern in ecological systems over the past
years. This interest is motivated by the desire to construct
valid models which extend across many scales. Spatial methods
must quantify pattern, discriminate types of pattern, and
relate hierarchical phenomena across scales. Wavelet...
Accurate measurement of forest productivity is fundamental to understand the carbon balance of forested ecosystems. Recent changes in climate highlight the importance of developing methods to measure forest productivity so that sound economic and environmental decision can be made. Efforts to measure forest productivity across the landscape using remote sensing...