Aporte en Elementos Nutritivos por la Hojarasca de un Bosque Adulto de Pinus radiata

Abstract

The mean annual litter production (between 1981-84). in a 25-28 year-old Pinus radiata. D. Don stand near Valdivia city (39°48'S , 73°14'W) was relatively stable a t aroun d 3.90 0 kg dry matte r (75°C) pe r há. It has a distinct seasonal variability tha t affects the corresponding nutrient contribution . The average annua l nutrient contribution and his corresponding concentration (% dry weight 105°C) was as follows: ash 104 kg/há (2.6%) , carbón 2.060 kg/há (52.7%) , nitrogen 27,4 kg/ h á (0,74%) ; phosphorou s 3,1 kg/h a (0.08%) ; sodium 1,3 kg/h á (0,03%) ; potassium 14,1 kg/há (0,37%) : calcium 21,3 kg/há (0,51% ) and magnesium 4,4 kg/há (0,11%).
Carbon, nitrogen, sodium and magnesium concentratio n remained nearly constant between seasons. Potassium and phosphorou s decreases from summe r to spring, due to lixiviation by rain and also to a significant participation of mal e flowers in spring. Male flowers in litter are less concentrate d by potassium and calcium. somewha t mino r in magnesium, sodium and phosphorou s and higher in nitrogen. Consecuently. calcium which has a rathe r stable pattern , decreases in spring due to the explained cause.