• Alterations in condition of cottontail rabbits (Sylvilagus floridanus) on rangelands following brush management

      Lochmiller, R. L.; Pietz, D. G.; McMurry, S. T.; Leslie, D. M.; Engle, D. M. (Society for Range Management, 1995-05-01)
      Although the use of herbicides and prescribed fire have been shown to increase density of cottontail rabbit (Sylvilagus floridanus) populations, the impact of such brush management practices on their condition has not been explored. We used discriminant analysis to investigate responses of overall physical condition of cottontail rabbits (n = 422 adults) to brush management and succession on replicated disturbed and undisturbed upland hardwood forest-tallgrass prairie over a 6-year period. Five different disturbed habitat types were experimentally created using herbicides (tebuthiuron or triclopyr), fire, or a combination of both. Parameters that were important discriminators of rabbit physical condition among habitat types and post-disturbance successional changes included indices of kidney fat and parasitism, and relative masses of spleen, liver, and dried stomach digesta. Brush management practices using herbicides influenced overall condition of rabbits, but the type of habitat disturbance was not important. Effects on overall body condition of cottontail rabbits from burning disturbed habitats were not apparent until later seral stages when production of herbaceous dicots declined and vegetative composition more closely resembled that of undisturbed areas.
    • New concepts for assessment of rangeland condition

      Adams, D. C.; Short, R. E.; Pfister, J. A.; Peterson, K. R.; Hudson, D. B. (Society for Range Management, 1995-05-01)
      Range condition score or classification does not tell us, in a general sense, much of what managers and the public want to know about rangelands. Range condition is not a reliable indicator, across all rangelands, of biodiversity, erosion potential, nutrient cycling, value for wildlife species, or productivity. Succession, the basis for the current concept of range condition is not an adequate yardstick for evaluation of rangelands. The Society for Range Management (SRM) established the Task Group on Unity in Concepts and Terminology which has developed new concepts tor evaluation of the status of rangelands. These concepts are based on the premise that the most important and basic physical resource on each ecological site is the soil. If sufficient soil is lost from an ecological site, the potential of the site is changed. The Task Group made three recommendations, which were adopted by the SRM: 1) evaluations of rangelands should be made from the basis of the same land unit classification, ecological site; 2) plant communities likely to occur on a site should be evaluated for protection of that site against accelerated erosion (Site Conservation Rating, [SCR]); and 3) selection of a Desired Plant Community (DPC) for an ecological site should be made considering both SCR and management objectives for that site.