The solution of coupled neutronic/thermal hydraulic nuclear reactor calculations
requires the treatment of the nonlinear feedback induced by the thermal hydraulic
dependence of the neutron cross sections. As a result of these nonlinearities, current
solution techniques often diverge during the iteration process. These instabilities arise
due to the low level...
This study examined the occurrence of coarse woody debris (i.e., pieces greater than 0.15 m in diameter and 2.0 m in length) in first- through fifth-order streams located within the Drift Creek Basin of the Oregon Coast
Range. Nine "tributary reaches" were surveyed to determine how three land management treatments...
Dramatic declines in many species of demersal fishes off the West Coast have resulted in the designation of nine commercially important species as being overfished. While the causes of those declines are not clearly understood, the fact remains that a paucity of life history and abundance data exists for many...
Several reports related to dams and dam removal have been released this decade by non-governmental organizations including Dam Removal: Science and Decision Making by The Heinz Center which focused on small dams, since most of the dams removed to date as well as those likely to be removed in the...
A taxonomic investigation was made of 24 taxa belonging
to the section Trichodium (Michx.) Trin., of
Agrostis, and the genus Podagrostis. Experimental methods
were employed, including: uniform garden culture of transplants
and plants grown from seeds collected in natural
populations; breeding studies; physiological and phenological
investigations; cytological studies; ecological
studies...
Recent evidence suggests that population declines of some avian species may be driven primarily by reduced quantity and diversity of early-successional habitat on the breeding grounds. Increasing intensity of forest management on private lands and decreased harvest rates on federal lands has resulted in a loss of the diverse early-successional...
The combined effects of habitat loss, degradation, and fragmentation pose a serious threat to Earth's biodiversity, imperiling even relatively common species. 'Habitat' is necessarily a species-specific concept, and investigations of bird diversity relationships and subsequent efforts to prioritize conservation areas, are challenged by the difficulty of estimating complex habitat gradients...
Society derives many critical and irreplaceable values from forests. With a growing global human population and rates of consumption, forests are under increasing pressure to provide all these values simultaneously. To meet societal demands for wood products, tree plantations are becoming increasingly common and are replacing native forests. Yet, forests...