西双版纳橡胶林、澳洲坚果林凋落物动态

在中龄(定植10 a左右)橡胶林、老龄(定植30 a以上)橡胶树林和本区域种植面积较大、处于盛产期(定植15 a左右)的澳洲坚果林,连续3年调查研究了各林型的凋落物量月动态、不同季节凋落物组分的变化,分析了影响凋落物量动态和组分变化的多种因素。结果表明,在凋落物量上,中龄橡胶林(4.76±0.80)t·hm~(-2)·a~(-1)显著低于老龄橡胶林(7.80±1.12)t·hm~(-2)·a~(-1)(t=5.608,P0.05),而澳洲坚果林(7.00±2.45)t·hm~(-2)·a~(-1)与老龄橡胶林相当(t=0.603,P=0.608);在凋落节律上,"双凋落峰"为3个林型的共有特征,但高峰期出现的时间有所不同;不同林型的凋落物组成比例也有所差异,橡胶林的凋落物总量格局主要由叶和枝凋落动态决定,而澳洲坚果林的凋落总量格局还会受到花果凋落情况的显著影响。除了树种、年龄和品种等植物本身特性会直接影响凋落物动态,日照、温度及湿度等气象条件也是影响凋落物量和凋落物各成分比例的重要因素。为进一步探讨橡胶林凋落物分解和养分循环研究提供了基础数据,有助于深入了解橡胶林生态系统的结构和功能。

Litter dynamics of rubber plantation and macadamia plantation in Xishuangbanna

In a middle age (about 10 years) plantation,an elderly (more than 30 years) rubber plantation and a macadamia plantation in rich phase (about 15 years),a three-year consecutive investigation was conducted on monthly litter dynamics,seasonal change of litter composition and influencing factors.The results showed that the total amount of litter in the middle age rubber plantation (4.76 ± 0.80) t·hm-2·a-1 was obviously lower than that in the elderly rubber plantation (7.80 ± 1.12) t·hm2·a-1 (t =5.608,P ＜ 0.05),while in the macadamia plantation (7.00 + 2.45) t·hm2·a-1 it was approximate to the elderly rubber plantation (t =0.603,P =0.608).All the three plantations showed the litter rhythm with a ”double litter peak” feature,but the time of peak occurrence was different.The composition ratio of litter varied among the three plantations.The litter pattern in rubber plantation was mainly determined by the litter amount of leaf and branch,while in macadamia plantation it was also greatly affected by the litter amount of fruits and flowers.Although the internal traits of plants itself (species,age and variety) directly affect litter dynamics,some meteorological conditions (sunshine,temperature and humidity) are also important factors influencing litter amount and composition.This study could provide basic data for the further exploration of litter decomposition and nutrient cycling in rubber plantation,and may help deeply understand the structure and function of rubber forest ecosystems.