An analytical algorithm to formulate a sparser set of adjacency constraints than the conventional algorithm is proposed. Utilizing matrix algebra applied to an adjacency matrix, constraints are systematically and efficiently derived by the proposed algorithm. The proposed algorithm is proved to provide a true set of adjacency constraints in the...
As part of the effort to evaluate TRIM (Timber Resource Inventory
Model) for the next RPA National Assessment, a study was conducted
using natural pine stands in North Carolina. TRIM has been used for
regional timber supply studies in both the Pacific Northwest and the
South (Southern Timber Supply Study)....
Salmon survival and eventual recruitment success have long been thought to be determined within the first summer following ocean migration. Juvenile growth during this period is largely influenced by ocean conditions such as temperature, prey availability, abundance, and quality. Shifts in these conditions due to climatic perturbations are particularly prevalent...
We present a new nitrogen isotope model incorporated into the three-dimensional ocean component of a global Earth System Climate Model designed for millennial timescale simulations. The model includes prognostic tracers for the stable nitrogen isotopes, ¹⁴N and ¹⁵N, in the nitrate (NO₃ˉ), phytoplankton, zooplankton, and detritus variables of the marine...
The effects of harvesting Pacific hake (Merluccius productus)
were examined with a multi-species numerical model composed of
seven logistic growth equations coupled by a food web. The
food web was composed of: California sea lions (Zalophus
californianus), hake, sablefish (Anaplopoma fimbria), spiny
dogfish (Squalus acanthias), a generic rockfish species
(Sebastes...
The issue of global climate change and an increasing interest in the reduction of fossil fuel carbon dioxide emissions by using forest biomass for energy production has increased the importance of quantifying forest biomass in recent years. The official U.S. forest carbon reporting is based on the forest biomass estimates...
Descriptions of the fire regime in the Douglas-fir/western hemlock region of the Pacific Northwest traditionally have emphasized infrequent, predominantly stand-replacement fires and an associated linear pathway of stand development, where all stands proceed along a common pathway until reset by the next fire. Although such a description may apply in...
The following report Introduces a documentation scheme for flow
oriented ecosystem models and shows its application to a carbon-water
model developed within the coniferous biome. This documentation scheme
has remained operative through revision of this model and expansion of
It to include nutrient flows. This model and subsequent versions are...
Equations for predicting the probability of a tree's dying in the
next 5 years are presented for eight conifer and eight hardwood
tree species from southwest Oregon. A logistic equation form was
used to characterize the probability of mortality. The parameters
of the equation were estimated using weighted, maximum likelihood...