Orientation in Cave-Dwelling wood rats

Summary Allegheny wood rats (Neotoma floridana magister) are occasionally found beyond the light penetration zone in caves. The means of orientation used by cave-trapped rats were studied using a radial maze and double-platform jumping tasks. The effects of various sensory manipulations upon their performances were evaluated, including visual deprivation, reversible deafening, control of chemical cues, and vibrissae trimming. The rats performed best when visible light was available, but they were able to do the tasks in the absence of light as long as their hearing was intact. Manipulation of other sensory cues had no effect. Intact animals seldom produced sounds when ambient sounds were available, but when these were very soft they did produce nonvical sounds. It appears that these cave-dwelling wood rats use acoustic means of orientation in the dark and that they are able to use some environmental sounds when these are available.     

Missing the trees for the forest? Bottom-up policy implementation and adaptive management in the US natural resource bureaucracy

For decades, natural resource agencies in the United States have attempted to restore ecosystems using adaptive management, a process that emphasizes experimental learning to reduce uncertainty. Most studies show that it rarely occurs in practice and explain implementation failures as organizational issues. This study draws on policy implementation theory to suggest that behaviors and attitudes of individuals may better explain implementation gaps. This comparative case study finds differences between experts implementing adaptive management in the Fish and Wildlife Service and the United States Geological Survey. These include differences in attitudes, perceptions, and behaviors aimed at promoting individual autonomy, performance standards, and defending individual interests on the job. Policy implications are twofold: first, that individual behaviors impact adaptive management implementation and intrinsic motivation to perform such functions. Second, regardless of agency, experts view their work as a social good. This suggests that a devolved planning process may remedy implementation obstacles.     

Gas and Aerosol Loadings at Holme Moss 1996–1998 Measurements and Analysis Using Back-Trajectory Clustering

A continuous two-year atmospheric datasetcomprising gas and aerosol loadings from amountain site in northern England (Holme Moss,W1°5130 N53°320) is presented. The data are analysed with respect to three-dayback-trajectories that are grouped according to aclustering technique that allows speed, directionand curvature of the airmass track to beconsidered. The technique is successful inseparating the data into chemically distinctsubsets. Up to 29% of the variance in the datais explained by back-trajectory clusters. Slow trajectories are associated with highloadings especially for the oxides of nitrogen,which may imply a local source for much of thesuspended pollutant. The data suggest thatproduction of nitrate and sulphate is limited byoxidant availability at least in the winter. Itmay be possible to optimise the analytical powerof the technique by increasing the importance ofrecent airmass track in determining clusterallocation. This applies especially to the totalsulphur loading.     

Response of Bean and Tobacco to Ozone: Effect of Light Intensity,Temperature and Relative Humidity

Pinto bean (Phaseolus vulgaris, L.) and Bel W₃ tobacco (Nicotiana tabacum, L.) were grown and exposed to 40 pphm ozone for 1 hr under a range of light intensities, temperatures, and relative humidities. Foliar injury to the more sensitive plant leaves was determined on the third day after exposure. Each atmospheric factor was independently assessed. Two significant three-way interactions were found: exposure light intensity by growth light intensity by species, and growth temperature by exposure temperature by species. Three significant two-way interactions were found for humidity: growth humidity by exposure humidity, growth humidity by species, and exposure humidity by species. The sensitivity of each species to ozone changed with changes in each environmental condition.