Many multispecies models have assumed that prey density determines per-capita predator consumption rates, following a functional response relationship. However, empirical evidence suggests that a predator’s diet can also be influenced by a variety of environmental factors, including interactions with other predators. We used diet and abundance data from National Marine...
A theoretical framework for economic fishery management was
developed. Extensive isocline analysis of a general fishery model
yielded a detailed look at the possible equilibrium behavior of a
system that was allowed to vary in terms of the levels of its
environmental parameters, its composition, and the response functions
governing...
A generalized mathematical model of ecosystems is
developed. The model begins with the general class of
systems known as state-determined systems, in which the
time-derivative of each state variable is a function of some
subset of the set of all system state variables and
.environmental parameters. A formal basis is...
This study quantified long-term changes in streamflows associated with clear-cutting and road construction and examined alternative hydrologic mechanisms to explain stream hydrograph changes in the Cascades Range, western Oregon. We examined differences in paired peak discharges for 150 to 375 storm events for five basin pairs, using 34-year records from...
Here we correct an error in the calculation of the percent change in peak discharges associated with timber harvest and road construction in small, experimentally treated basins by Jones and Grant [1996]. This correction reduces the estimated magnitude of changes, but it does not affect the direction or statistical significance...
Thomas and Megahan [1998] provide a thoughtful reanalysis of our earlier paper [Jones and Grant, 1996]. Thomas and Megahan [1998] (hereinafter referred to as T&M) reacted to three assertions made by Jones and Grant [1996] (hereinafter referred to as J&G): (1) "forest harvesting has increased peak discharges by as much...
A key challenge for resource and landscape managers is to predict the consequences of climate warming on streamflows and water resources. Different approaches are being developed to forecast the direction, magnitude, and timing of future streamflow changes in specific landscapes. One approach that is being utilized in the Pacific Northwest...
Florida is a hotspot for nonindigenous fishes with over 30 species established, although few of these are small-bodied species. One hypothesis for this pattern is that biotic resistance of native species is reducing the success of small-bodied, introduced fishes. The eastern mosquitofish Gambusia holbrooki is common in many freshwater habitats...