西双版纳热带季节雨林与橡胶林不同径级根分解

A decomposition dynamics study of different-size roots between a tropical rainforest and a rubber plantation in Xishuangbanna,Yunnan,SW China

通过分解网袋法对西双版纳2种重要森林类型———热带季节雨林和橡胶林(Hevea brasiliensis)4种不同径级的根(细根<2 mm,2 mm<小根<10 mm,10 mm<中根<20 mm,粗根>20 mm)进行为期1 a的研究,发现热带季节雨林根系分解速率小于橡胶林;细、小根分解速率大于中、粗根;根分解速率与根自身C/N,C/P有强相关性;热带季节雨林细根、小根、中根、粗根日分解系数分别为0.001 0,0.002 5,0.000 7,0.000 7,橡胶林细、小、中、粗根分解系数分别为0.003 0,0.001 9,0.001 3,0.001 7.

A buried bag method was used to investigate the decomposition dynamics of different - size roots in two main tbrests type in Xishuangbanna, Yunnan Province, the tropical rain forest and rubber plantation. After one -yearg experiments, it was found that：①For different forests, the root decomposition rate in rain forest was much lower than that in rubber plantation;②For the same forest, the decomposition rates of fine and small roots were much higher than those of medium and coarse roots ; ③ The root decomposition rate correlated with C - N or C - P ratio, which the higher the C - N or C - P ratio was, the lower the decomposition rate was ; ④In rain forest, the daily decomposition coefficients of fine （ 〈 2 mm ）, small （ 2-10 mm ）, medium （ 10-20 mm） and coarse （ 〉 20 mm ） root were O. 001 0,0. 002 5,0. 000 7,0. 000 7, respectively,while in rubber plantation, were 0. 003 0,0.001 9,0. 001 3,0. 001 7 ,respectively.