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Publications

Below is a list of WERC's peer-reviewed publications. If you are searching for a specific publication and cannot find it in this list, please contact werc_web@usgs.gov

Filter Total Items: 3724

Wilderness permit compliance and validity Wilderness permit compliance and validity

In Yosemite National Park, 92 percent of the parties using back country areas had permits. Parties without permits were smaller in size and stayed for shorter periods of time. For all parties with permits, 62 percent made changes to their trips. Parties changing their trips in both time and space accounted for 27 percent of the total, while 14 percent made temporal changes only, and 21...
Authors
J. W. van Wagtendonk, J.M. Benedict

Travel time variation on backcountry trails Travel time variation on backcountry trails

Numerous interrelated factors influence the travel times of hikers and riders on backcountry trails. This study sought to quantify those factors which were thought to be most important in affecting trail speeds. The travel times of 897 backpacking parties, 634 day hiking parties, and 111 riding parties were obtained from gentle (0.75%), moderate (5.0%), and steep (12.5%) trail segments...
Authors
J. W. van Wagtendonk, J.M. Benedict

Undersea topography and distribution of dolphins of the genus Delphinus in the Southern California Bight Undersea topography and distribution of dolphins of the genus Delphinus in the Southern California Bight

Aerial surveys totalling 21,902 km were analyzed in the Southern California Bight. Although the genus Delphinus is easily recognizable from aircraft, the different species are not detectable in these flights. Delphinus occur more frequently in areas of high relief than in areas of low relief. The depth of the water does not appear to influence distribution of Delphinus. The availability...
Authors
Clifford A. Hui

Alcoholic fermentation in swamp and upland populations of Nyssa sylvatica: Temporal changes in adaptive strategy Alcoholic fermentation in swamp and upland populations of Nyssa sylvatica: Temporal changes in adaptive strategy

Both the upland and swamp varieties of Nyssa sylvatica respond initially to flooding with an acceleration of ethanol production. Under continued flooding the roots of the upland variety sylvatica have decreased rates of ethanol production, very likely a result of the progressively worsening necrosis of the root system. Few of these plants survive a full year of flooding. The swamp...
Authors
Jon E. Keeley, E. H. Franz

Population differentiation along a flood frequency gradient: Physiological adaptations to flooding in Nyssa sylvatica Population differentiation along a flood frequency gradient: Physiological adaptations to flooding in Nyssa sylvatica

Throughout the southeastern United States the hardwood Nyssa sylvatica (sensu lato) is distributed along a soil moisture gradient from upland sites, which are never flooded, to floodplains, which are periodically flooded and drained to permanently flooded swamps. Population differentiation with respect to flood tolerance and related physiological attributes was investigated using 1—year...
Authors
Jon E. Keeley
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