A Prelim inary Study on L itter Fa lls of Six Kinds ofPlanta tions in the Tropica l South Asia

The amount and rhythm of litter falls inM ytilaria laosensis, B etu la a lnoides, Castanopsis hystrix, M icheliam acclurei, Pinus m assoniana, and Cunningham ia lanceola ta p lantations located at Experimental Center of Trop icalForestry, CAF, were studied. The results showed that there existed different dynamic change and litter fall amountfor different tree p lantation. Among 6 stands, M ytilaria laosensis had the most leaf and miscellaneous litter falls,which were 4 748. 23 and 1 881. 07 kg·hm-2 ·a-1 , and B etula alnoides had the lowest, which were 2 641. 32 and153. 88 kg·hm-2 ·a-1. Pinusm assoniana had the most leaf litter fall, which was 902. 94 kg·hm-2 ·a-1 , whileCunningham ia lanceolata the lowest, which were 149. 93 kg·hm-2 ·a-1. For annual total litter fall amount,M ytilaria laosensis was the highest (7 095. 76 kg·hm-2 ·a-1 ) and B etula alnoides the lowest (3 309. 05 kg·hm-2 ·a-1 ). The annual total litter fall amounts of Castanopsis hystrix, M ichelia m acclurei, Pinusm asson iana, andCunningham ia lanceolata were similar, ranged between 5 555. 61 - 5 864. 87 kg·hm-2 ·a-1. The ANOVA resultsof the annual total litter fall amount showed that there existed extremely significant differences among tree species.By multip le comparisons, it was showed that there existed extremely significant difference in annual total litter fall amount betweenM y tila ria laosensis and the other 5 species, between Castanopsis hystrix, Cunn ingham ia lanceolataand B etula alnoides and M ichelia m acclurei and Pinus m asson iana, and between M ichelia m acclu rei, Pinusm assoniana and B etula alnoides.