青冈常绿阔叶林钾的生物循环研究

本文对分布于浙江建德的青冈常绿阔叶林K的生物循环进行了研究。群落各代表种类的K浓度大都在0．2～0．4％之间，其令藤本、草本＞下木层＞乔木层、亚乔木层植物，各器官中K浓度叶＞枝、根＞干。青冈中K浓度为下木层＞乔木层＞亚乔木层；幼嫩、同化和生殖器官中积累了较多的K。凋落物凋落之前，K有被回输的现象。K在群落中现存量为431．64kg／hm2，死地被层中积累量为25．88ky／hm2，土壤（A0－B层）中储存量为64298kg／hm2。群落K的存留量为53．83ky／hm2.a；归还量为51．89ky／hm2．a，其中大部分通过穿透水归还（占70％）；吸收量为105．72kg／hm2．a。降水输入了7．10kg／hm2．a的K。与世界上其它森林类型相比，青冈林K的循环速申和利用效申是对一定水热条件的正常反映。

BIOCYCLE OF POTASSIUM IN AN EVERGREEN BROAD - LEAVED FOREST DOMINATED BY CYCLOBALANOPSIS GLAUCA IN SE, CHINA

Biocycle of potassium in a subtropical evergreen broad - leaved forest dominated by Cyclobalanopsis glauca growing on red soil in Zhejiang was elucidated in this paper. The concentration of K in most representative species were 0. 2 ~ 0. 4 % . The order of them in various layers were Liana and herb > Understory > Tree and Subtree, and that in various organs were leaf > branch, root > trunk. The Sequences of the concentrations of K in C. gleuca were understory > tree > Subtree, young and assimilation > old and nonassimilation organs, reproductive > vegetative organs. K was resorbed before litter senesced and fallen. The standing crop of K in the community was 431. 64kg/hm2, that in the litter layer was 25. 88kg/hm2, and in the soil(A0 B) was 64298kg/hm2. Retention of K was 53. 83kg/hm2. a. Return of it was 51. 89 kg/hm2. a, in which via throughfall occupied 70%. Uptake of K was 105 - 72kg/hm2.a. Annual input of K through incident precipitation was 7 - 10kg/hm2. Comparing with other forest types, cycling rate and use efficiency of K in this ecosystem was reflected to the environmental condition in the corresponding region.