02191naa a2200337 a 450000100080000000500110000800800410001910000120006024501190007226000090019152013480020065000130154865000120156165000120157365000130158565000100159865000110160865000150161965300110163465300230164565300100166865300110167865300310168965300210172065300140174170000150175570000140177070000140178470000160179877300390181417890491996-06-03       1982    bl ---       0--  u    #d1 aUHL, C.  aEcosystem recovery in Amazon caatinga forest after cutting, cutting and burning and bulldozer clearing treatments.  c1982  aA study of ecosystem recovery following forest cutting, forest cutting and burning, and forest clearing by bulldozing was conducted in Amazon caatinga forest in the upper Rio Negro Region of southern Venezuela. Ecosystem recovery was evaluated by measuring vegetation composition, biomass, nutrient accumulation, soil characteristics, and nutrient leaching. As disturbance increased in intensity, the early successional vegetation changed from primary forest trees (cut treatment) to successional woody species (cut and burned treatment) to forbs and grasses (bulldozed treatment). Soil nutrient levels were greater in both the cut and the cut and burned treatment plots than in the control forest three years after the disturbances presumably because of steady transfers of nutrients from the forest slash to the soil. Soil nutrient levels in the bulldozed plot were much lower than the control forest because of top soil removal. Aboveground biomass at three years was 1291 g m-2 in the cut site, 870 g m-2 in the cut and burned site, and 77 g m-2 in the bulldozed site. Given these rates of biomass accumulation, approximately 100 yr will be required for both the cut and the cut and burned sites to reach biomass levels characteristics of mature caatinga forest, while more than 1000 yr will be necessary in the case of the bulldozed site.  aAmazonia  aburning  acutting  aCaatinga  aCorte  aPlanta  aTratamento  aAmazon  aEcosystem recovery  aPlant  aQueima  aRecuperacao de ecossistema  aRio Negro region  aTreatment1 aJORDAN, C.1 aCLARK, K.1 aCLARK, H.1 aHERRERA, R.  tOikosgv.38, n.3, p.313-320, 1982.