林下套种阔叶树的马尾松林凋落物生态学研究 Ⅲ.凋落物现存量及其养分含量

在马尾松林下分别套种拉氏栲、青栲、闽粤栲、格氏栲和苦槠,形成针阔混交异龄林.对这5个混交林群落以及马尾松纯林的林地凋落物(包括A00和A0层)进行了收集、取样和化学分析.结果表明,上述6个群落的林地凋落物现存量分别为8448.0、15565.8、11993.7、12718.6、6974.2和5020.0kg·hm-2,其中A00层在各群落中所占比例分别为47.2%、59.6%、51.3%、61.0%、85.4%及86.3%,平均为61.7%.凋落物中各养分元素的含量在群落和组分之间存在明显差异,但总的趋势表现为Ca>N>Mg或K>P.6个群落的林地凋落物中,5种营养元素在A00层中的总含量范围为91.56～210.85kg·hm-2,而在A0层的含量范围为21.95～156.15kg·hm-2.

Forest Litter Ecology in Masson′s pine Stand and Its Mixed Forests Formed by Inter-planting with Hardwood Tree SpeciesⅢ.Biomass and Nutrient Content of Forest Litter

Five uneven aged conifer hardwood forest communities were developed after Castanopsis lamontii,Cyclobalanopsis myrsinaefolia,Castanopsis fissa,Castanopsis kawakamii and Castanopsis sclerophylla,were separately interplanted under the canopy of mature Pinus massoniana plantationsAll the litter in the forest floor(including layers A00 and A0)was collected,sampled and chemically analysed in the above fives mixed species communities and also in pure Masson′s pine standThe results showed that biomass of forest litter were,respectively,8 4480,15 5658,11 9937,12 7186,6 9742,and 5 0200 kg·hm-2,of which litter in layer A00 makes up of 472%,596%,513%,610%,854%,and 863% of the total,respectively,averaging 617% Significant differences in nutrient concentrations existed between forest communities and litter components,but the elements consistently revealed the same trend,decreasing in the order:Ca>N>Mg or K>P Total nutrient contents in the forest floor ranged from 9156 to 21085 kg·hm-2 in layer A00,and 2195 to 15615 kg·hm-2 in layer A0