THE MINERAL-ELEMENT CONTENT OF LITERFALL IN A LITHOCARPUS XYLOCARPUS FOREST IN THE AILAO MOUNTAINS

The accumulation and decomposition of litter were studied over two separate years in an undisturbed Lithocarpus xylocarpus forest at c.2400-2600 m.altitude southwestern highlands of China.Mean annual litter fall amounted to 5.5 t ha-7.10 t ha^-180% of which was leaves containing 91.5 kg ha^-1 nitrogen,3.7 kg ha^-1 phosphorus,101 kg ha^-1 calcium,5.7 kg ha^-1 alminum,42.1 kg ha^-1 potassium,0.3 kg ha^-1 sodium,10.7 kg ha^-1 magnesium,5.6 kg ha^-1 manganese,and 1.9 kg ha^-1 iron.Litter falls have seasonal peaks from April to June,and May to October during the heavy rains.From January to December in 1984,the total rainfall was 1510.5 mm,and from January to Nevember in 1985,the total rainfall was 1975.5 mm.The estimater of annual rate parameter for litter disappearance were based on the relationship between the standing crops of litter on the ground and the annual litter production,ranging from 0.73 to 0.94.The leaf decomposition of seven tree species(Lithocarpus xylocarpus,Lithocarpus chintungensis,Castanopsis wattii,Cyclobalanopsis stewar-diana var.longicaudata,Schima noronhae,Illicium macranthum,Vaccinium duclouxii.) and a widespread bamboo(Sinarundinaria nitida),was studied ever one year by enclosing the litter in plastic mesh.For freshily-fallen leaves decomposition varied from species to species(from 68-96% yr),but it was not affected by the sites of collection.The ash nutrient content of eight species were determined,and the contents varied from species to species.