In this study, we examine salinity stress tolerances of two populations of the invasive species New Zealand mud snail Potamopyrgus antipodarum, one population from a high salinity environment in the Columbia River estuary and the other from a fresh water lake. In 1996, New Zealand mud snails were discovered in...
Diadora aspera is an intertidal keyhole limpet found in the mid-tidal zone. Its activity pattern was estimated under laboratory conditions using time-lapse-photography and manometric determinations of oxygen consumption. Statistical and computer analyses of the photographic data suggest the presence of both a 24 hour and a 12-13 hour rhythm in...
The heart rate, oxygen consumption, survivorship, and 1-lactate
accumulation were determined in the intertidal limpets Collisella pelta
and Collisella digitalis in relation to laboratory desiccation at 15°C
or 30°C. Water loss was computed as a percentage of total initial body
water (wet weight - dry weight). Although water was lost...
Soil column studies were performed on a chromium contaminated soil from the United
Chrome Products Superfund Site currently undergoing a pump-and-treat cleanup process. The
goal of the research was to provide insight into the feasibility of chemically changing the injection
fluid of the pump-and-treat system to enhance hexavalent chromium (Cr(VI))...
The intermittent upwelling hypothesis (IUH) predicts that the strength of
ecological subsidies, organismal growth responses, and species interactions will vary
unimodally along a gradient of upwelling from persistent downwelling to persistent upwelling,
with maximal levels at an intermediate or ‘‘intermittent’’ state of upwelling. To test this model,
we employed the...
A new species belonging to the lichen genus Physconia is described from Alaska and the Canadian and American Rocky Mountains and adjacent forested regions. It is also reported from China, Nepal, India and Siberia. The new species, Physconia labrata, is superficially similar to P. perisidiosa, but can be distinguished by...
Phytoplankton biomass in high-nitrate, low-chlorophyll (HNLC) ocean regions exhibits a pronounced stability: variation occurs only within a narrow range of values. The magnitude of this variation has profound ecological and geochemical consequences. While mechanisms believed to set the upper limits to HNLC phytoplankton biomass (iron limitation, microherbivore grazing) have received...
Streamflow response to rainfall is controlled by the net water budget and the routing of rainfall to stream channels. In rain-dominated forested regions, including the Oregon Coast Range, water budget aspects of forest hydrology are better quantified than water routing. As a result, most of the commonly used forest hydrology...
A practical demonstration of a method for
rating forest stands as to their probability of
defoliation by the Douglas-fir tussock moth
using aerial photographs and available cruise
data was done in the Palouse Ranger District,
Clearwater National Forest, Idaho.
A nonlinear computer program, RISK, was used to
identify significant independent...
Sufficiently large lake loads provide a means of probing rheological stratification of the crust and upper mantle. Lake Minchin was the largest of the late Pleistocene pluvial lakes in the central Andes. Prominent shorelines, which formed during temporary still‐stands in the climatically driven lake level history, preserve records of lateral...