02036naa a2200181 a 450000100080000000500110000800800410001902200140006010000190007424501380009326000090023152015110024065000100175165000190176165300180178065300140179877300420181212840671993-05-26       1979    bl uuuu     u00u1 u    #d  a0100-45571 aLIMA, W. de P.  aAlteracao do PH, condutividade e das concentracoes de Ca, Mg e P da agua da chuva em floresta de Pinus caribaea Morelet var. caribaea  c1979  aSamples of precipitation collected in the open and of troughfall collected under a plantation of Pinus caribaea var.caribaea were analysed for pH, conductivity and concentrations of calcium magnesium and phosphorus during a 25 week period from october 1976 through march 1978. The pine forest was planted in 1969 and was located at the campus of the ESALQ-USP, in Piracicaba,State of Sao Paulo. Average annual precipitation in the study area is 1280mm, from which about 1000mm fall during the rainy season (october through march). Average annual temperature is about 20oC. Precipitation was measured weekly in a nearby open area using 6 plastic rain gauges. Throughfall was also measured weekly, using 12 plastic collectors which were randomly distributed under the forest. As soon as collected, the samples were taken to the laboratory for chemical analyses. pH was measured with a pH-meter; conductivity was measured with a Hach 2511 Conductivity Meter; calcium was determined by titration with EDTA,and magnesium was determined by the calculation method; phosphorus was determined by the stannous chloride method. pH was on the average 4,5 in the throughfall water, against an average value of 5,2 in the rain water. Average conductivity, on the other hand, varied from 18 umho for the rain water, to 57,8mmho for the throughfall water. For the 15 months of the study period, approximately 10 kg/ha of calcium and 6kg/ha of magnesium have been washed from the pine forest canopy to the soil by rainfall.  awater  aPinus Caribaea  aAgua da chuva  aRainwater  tIPEF, Piracicabagn.18, p.37-54, 1979