• Plant responses to pine management and deferred-rotation grazing in north Florida

      Lewis, C. E.; Tanner, G. W.; Terry, W. S. (Society for Range Management, 1988-11-01)
      Responses of herbaceous and woody plants to combinations of 4 pine management and 4 grazing management systems were tested on a wet-flatwoods site in the pine-wiregrass vegetation type of north Florida. Frequency of occurrence of herbaceous species and foliar cover of woody species were determined in natural stands of 50-year-old slash and longleaf pine (Pinus elliottii Engelm. and P. palustris Mill.) and compared to similar forest sites that were harvested and site prepared by double-chopping and not replanted with slash pine, or replanted to 1,112 trees/ha in single- and double-row configurations. In addition, these sites were ungrazed or grazed using 3 deferred-rotation systems. Prescribed burning in the natural stands increased occurrence of most herbs and stimulated new species to occur, but had little effect on woody plant composition. However, harvesting of pines and double-chopping resulted in the occurrence of many new herbaceous species and increased occurrence of most initially present. Pineland threeawn (Aristida stricta Michx.), the major herb, initially decreased in occurrence with intensive site disturbance. Six years after disturbance, most herbaceous species were declining in occurrence. Grazing or growth of replanted pines had little influence on occurrence of herbaceous species. Both burning and mechanical disturbances initially reduced foliar ground cover of most woody species; however, few species were eliminated from the community. Most woody species were recovering within 6 yr from treatment, but succession was somewhat slower on mechanically treated areas. Survival and growth of planted pines were not affected by grazing, nor did planting configuration affect pine growth.
    • Species diversity and diversity profiles: concept, measurement, and application to timber and range management

      Lewis, C. E.; Swindel, B. F.; Tanner, G. W. (Society for Range Management, 1988-11-01)
      The concepts and use of several diversity assessments are presented and applied to a practical situation. Burning, mechanical methods of site preparation, and cattle grazing are common disturbances in forests of the South. Their influence on plant diversity indices are examined in a longleaf-slash pine forest of north Florida. Species richness, Shannon's index, and Simpson's index showed increases in diversity shortly following burning and site preparation and a trend toward pre-treatment conditions after 6 years. Deferred-rotation grazing systems had no influence. Comparative diversity profiles showed similar trends but were more informative by providing both qualitative and quantitative information. These techniques are useful for assessing community responses to management practices, that is, they are effective methods for understanding the impacts of forest management and range management practices on plant community structure and succession.