不同林龄人促更新林枯枝落叶层碳及养分贮量

摘要

Carbon ( C) and nutrient stocks of forest floor were studied in artificial regeneration Castan-opsis carlesii forests with stand ages of 21 , 31 and 49-year old in Shunchang , Fujian.The results showed that the standing crop of forest floor ranged from 3.94 to 4.95 t · hm-2 , with the maximum mass in the 31-year old forest and the minimum in the 49-year old forest .Concentrations of C , N, P and K were 44.09%~47.46%, 11.9~13.8 g· kg-1 , 0.5~0.9 g· kg-1 and 1.4~5.1 g· kg-1 , re-spectively.C concentrations of forest floor in 21-and 49-year old forests were significantly higher than those in 31-year old forest , while concentrations of N and P in forest floor of 49-year old forest were higher than those in the 21-and 31-year old forests.Also, forest floor in the 49-year old forest had the lowest K concentration .Forest floor C stock in the 21-year old forest was 1.03 and 1.23 times higher than those in the 31-and 49-year old forests , respectively .The K stock in 49-year old forest was far below it in 21-and 31-year old forests.Overall, carbon and nutrient pools of forest floor in different forests were related to forest characteristics , standing crop of forest floor , etc.%对福建南平顺昌县不同林龄米槠（Castanopsis carlesii）人促更新林枯枝落叶层和主要营养元素现存量进行测定，探究其随林龄的变化趋势。结果表明：不同林龄米槠人促更新林枯枝落叶层现存量为3.94～4.95 t · hm－2，其中49 a生人促林枯枝落叶层现存量最小，31 a生的最大。不同林龄枯枝落叶层C、 N、 P、 K的浓度分别为44.09％～47.46％，11.9～13.8 g · kg－1，0.5～0.9 g· kg －1，1.4～5.1 g· kg －1。21 a生和49 a生人促更新林枯枝落叶层C浓度明显高于31 a生林分。49 a生人促更新林枯枝落叶层N和P浓度均高于21 a生和31 a生林分，但该林分枯枝落叶层K浓度却最低。21 a生米槠人促更新林枯枝落叶层C贮量分别是31 a生和49 a生林分的1.03倍和1.23倍，49 a生米槠人促更新林K贮量远低于21 a生和31 a生。不同林龄枯枝落叶层碳和养分贮量差异与林分特征、各林分枯枝落叶层现存量及养分浓度等有关。