02980naa a2200277 a 450000100080000000500110000800800410001910000170006024501660007726000090024352021760025265000100242865000180243865000230245665000120247965000120249165000240250365000110252765000130253865300190255165300090257065300230257965300180260270000150262077300670263515233192023-06-02       1971    bl uuuu     u00u1 u    #d1 aPRATT, D. J.  aBush-control studies in the drier areas of Kenya. V. Effects of controlled burning and grazing management on Tarchonanthus/Acacia thicket.h[electronic resource]  c1971  aAbstract: An experiment is described that combined burning, the use of goats and preliminary slashing in two management systems appropriate to traditional cattle husbandry. Treatments were combined in a 23 factorial of split-plot design with two replicates and the experiment ran for 5 years. Burning soon opened the thicket canopy and increased the contribution of grass. The first two fires also killed over half of the original population of Dichrostachys cinerea and appreciable numbers of the tree species of Acacia, but populations of woody plants tended to increase through seedling establishment and no significant kill was obtained in the dominant thicket species, Tarchonanthus camphoratus or Acacia brevispica. Only at the third burn were dead plants of the latter recorded: although these included very few plants of Tarchonanthus, the vigour of this species, in terms of height, stem number and nitrogen and carbohydrate content, was much reduced. At the end of the experiment the grass yield from areas that had burnt thrice was over 3000 1b DM/ac, compared with 940 lb DM/ac from unburnt areas. All perennial grass species, including Themeda triandra and Panicum maximum, increased in frequency. The inclusion of goats in the grazing regime helped check the increase in woody plant population (but not in Dichrostachys) and led to significantly higher fire temperatures when these were recorded by the thermocolor method. The feeding habits of the goats, however, varied greatly according to the area of origin of the flock and browsing was more effective in slashed than unslashed areas. Slashing also facilitated even burning. It is suggested that the thicket association studied is a fire climax but that by continuing the burning regime a change to wooded grassland, with Acacia seyal and A. nilotica, could be effected; alternatively, fire could be used to reduce the vigour of the thicket species until they were susceptible to final control by arboricides. The choice between fire and other methods of control should depend upon the economic value of the grazing. Important among the factors that allow effective burning is low atmospheric humidity.  aGoats  aGrazing lands  aRotational grazing  aArbusto  aCaprino  aControle Biológico  aManejo  aPastagem  aAcacia thicket  aBush  aControlled burning  aTarchonanthus1 aKNIGHT, J.  tJournal of Applied Ecologygv. 8, n. 1, p. 217-237, Apr. 1971.