Summary
During the period of June 1974 to May of 1975, three floristics groups were studied in the Biological Reserve of Campina at BR-174 road. The principle task of the research was to quantify the input of nutrient ions and organic materials, for use by macro and micro populations as sources of energy and food, by rain from the forest canopy (stem-flow). The results (montly average) showed litlle differences in the concentrations of total-P. and nitrate-nitrogen, while ammonia nitrogen, organic nitrogen and magnesium, showed different quantities of leaching in each of the three floristic groups. The total nitrogen compounds, the most easily leached, were followed in decreasing order by calcium, magnesium and phosphorus for all system, except for Campina where magnesium ions showed greater concentrations than calcium. Total organic materials always had the greatest quantities of leaching. Seasonal variations in leaching of the nutrient ions and organic materials from the forest to soil are closely related to the duration, intensity and distribution of rain in the study site.