江西省不同森林类型下枯枝落叶的数量、节律与组成

经过对全省范围内主要林区广泛面上调查和在井冈山自然保护区的定位研究发现：（１）江西省森林枯枝落叶的凋落量因林型不同差异极大。表现为阔叶林＞混交林＞杉木林，其中落叶是主要的形式。（２）不同森林类型其枯枝落叶的凋落节律表现出明显的差异。（３）枯枝落叶每年归还到土壤的植物营养元素数量最多的是Ｎ，其次是Ｃａ，Ｍｇ和Ｐ，Ｋ，Ｍｎ。（４）不同林型的枯枝落叶归还到土壤的养分元素的数量表现出阔叶林＞混交林＞杉木林。（５）不同林型下地表保存的枯枝落叶层的构型、数量和各种营养元素贮量有极大的差异，表现为阔叶林＞混交林＞杉木林。值得注意的是，杉木林下的枯枝落叶层中Ｎ，Ｐ，Ｋ，Ｃａ，Ｍｇ的贮量仅分别为阔叶林中这些养分贮量的２１．６４％，２５．１１％，１１．９７％，２１．６８％和２４．２５％。

A STUDY ON THE QUANTITIES FALLING RATES AND COMPOSITIONS OF DIFFERENT FOREST LITTERS IN JIANGXI PROVINCE

After extensive invastigation in the main forest areas all over Jiangxi province and sitestudy in Jinggang Mountain,it is found that:1)the amounts of annual litter yields vary withforest types,behaving as broad-leaved forest>mixed forest>Chinese Fir forest, and the deadleaves are the principal parts of the litters;2)the rates of litter pbouction differ among foresttypes; 3)the most nutrient retured to soil by litters is N,following by Ca, Mg and K,P,Mn;4)the amounts of nutrient retured to soil by litters show as broad- leaved forest>mixed forest>Chinese Fir forest;5 )the thickness of the litter layers the dry matter quantities and theamount of nutrients contained in them under diferent forest differ remarkably showing as broad-leaved forest> mixed forest> Chinese Fir forest. It is noticeble that the amounts of N,P,K,Ca and Mg contained in the litter lay under Chinese Fir forest are only 21.64%,25.11%,11.97%,21.68% and 24.25 of those in the litter layers under broad- leaved forest,respectively.