The groundfish trawl fishery operating off the coasts of Oregon
and Washington 1985-1987 caught six major assemblages of species
which could be treated as units in developing mixed-species
management plans. Eighty-one percent of the tows observed on
commercial vessels were consistently placed in one of the assemblage
designations using three...
National Forest management in the Pacific Northwest is shifting
from a focus on commodity production to ecosystem management, in which
the health of the entire forest ecosystem is considered, rather than that
of a few key species. Ecosystem management includes retention of some
live trees following timber harvest (green-tree retention)...
Adequate management and scientific investigation of ecosystems
depends on classification of landscape systems based on all significant
bio-physical and associated cultural properties. The present
classification is a hierarchical systems design that can be modeled in
terms of a natural system interacting with its level-specific
environment. A watershed system in this...
Population dynamics, plant communities, and abiotic environments of three narrowly endemic, allopatric mariposa lilies (Calochortus Pursh) are described and compared. All were restricted to ultramafic soils in southwestern Oregon with high concentrations of nickel, zinc, and chromium, and low calcium to magnesium ratios. Soils inhabited by the three species differed...
The primary objective of this study was to develop methods for
the selection of temperature sensitive division (TSD) mutants of
Chlamydomonas reinhardtii. Such methods were developed and four
temperature sensitive (TS) mutants were isolated and partially
characterized.
Wild type (WT) cells of the plus mating type were synchronized
by a...
Atlantic menhaden, compared to gulf menhaden, exhibit
a life history pattern that appears to be adapted to a more
unpredictable reproductive environment. From experiments
on laboratory-reared eggs and larvae, Atlantic menhaden have
larger eggs with larger yolk volume. They are larger at
hatching, utilize their yolk faster, begin feeding at...
Two sets of experiments measured changes in the oxygen consumption of the euryhaline teleost Oreochromis niloticus during acclimation to progressively increased salinity. Six acrylic respirometers were constructed for this purpose. The salinities tested were 9, 18, 27 and 36 ppt, with 36 ppt considered as full strength seawater. Fish were...
This study was designed to provide information about the juvenile life history of coho salmon, Oncorhynchus kisutch, in the Tenmile Lakes in Oregon by 1) classifying scales of spawning fish and outgoing smolts (1+), 2) assessing the contribution of juvenile life history types to the returns of adults (3₂) and...
Lago Rupanco is located in the central plain of Chile
(Borgel, 1964) at 40° 50' S; 72° 30' W. It lies at 117 m
above sea level, and corresponds to type 28c of Hutchinson's
(1967) classification. Lago Rupanco is a warm, monomictic
lake, with winter circulation and summer stratification.
Physical,...