The dynamics of stands in the mid-elevation old-growth
Douglas-fir (Pseudotsuga menziesii) forests of the central western
Oregon Cascade Range were investigated using stand structure
analysis. Trees with different growth rates were commonly present
in the same stand, which resulted often in a weak correlation
between tree diameter and age. Thus,...
The Tailed Frog Ascaphus truei, the only species in the
family Ascaphidae found outside New Zealand, is a common inhabitant
of the mountain streams of the Northwestern United States and
British Columbia. The anatomical peculiarities of this primitive
anuran have been investigated, but no literature is available on the
digenetic...
Middle School represents a period of transition for the
students. This transition is present not only in physical change,
intellectual change, and emotional change, but also in terms of
the type of reading instruction these students receive. One
approach to reading instruction moves from a direct approach
focusing on specific...
Detection of L-serine and D,L-alanine by juvenile coho salmon (Oncorhynchus kisutch) was measured in a two-choice Y-trough. Threshold concentration for olfactory
detection of L-serine was 10-8 M for zero-age parr, 1O-7 M for yearling parr, 10-5 M for smolts in late April-early May, and 10-6 M for smolts in June....
In recent years, studies dealing with temperature regulation,
temperature sensitivity, and physiological responses to temperature
in lizards and other reptiles have increased tremendously. It is
notable that snakes have been largely ignored in such studies. This
no doubt is due to their less direct relationship to ancestral endotherms.
However, problems...
Since the early 1990s, declines in northern spotted owl (Strix occidentalis caurina) populations have been documented through extensive field surveys and range-wide demographic analyses. Although loss of late-successional forest has been credited as the primary cause for spotted owl population declines, environmental variation has also been shown to influence vital...
Studies were conducted to determine the nature of the interaction
between atrazine (2-chloro-4-ethylamino-6-isopropylaminos-
triazine) and magnesium on tomatoes. This interaction was
studied under two light regimes: continuous light and a 12-hour
photoperiod. Tomato plants were grown in sand cultures at three
levels of magnesium fertilization. Four weeks after planting,
atrazine...