施肥对西双版纳橡胶林土壤CO_2排放的影响

Impacts of fertilizer application on CO_2 emissions in rubber( Hevea brasilensis) plantation in Xishuangbanna,Southwest China

对土地的人工管理影响到土壤CO2的排放。西双版纳是中国橡胶主要种植区,施肥是橡胶林获取更好效益的主要管理措施之一。为探讨施肥对橡胶林土壤CO2排放的影响,选取西双版纳大面积种植的橡胶林,采用静态箱-气相色谱法开展了不同施肥处理试验。结果表明：（1）施肥处理没有改变西双版纳橡胶林土壤CO2排放的时间变化特征;（2）不同施肥处理和对照的西双版纳橡胶林土壤CO2排放均呈现出雨季大于干季的趋势,年排放总量在7.88~7.93 t C·hm-2·a-1;（3）不同施肥处理的土壤CO2月排放量大于对照;（4）施肥处理在一定程度上可促进土壤呼吸,使土壤CO2排放增加,但差异不显著（P〉0.05）。本研究结果为进一步揭示西双版纳橡胶林生态系统碳循环过程及其机理提供支持,为把握橡胶林碳平衡动态和应对全球变化提供参考,也可为橡胶林的可持续利用提供科学依据。

Land management has a significant influence on soil CO2 emission. Rubber trees have been planted in Xishuangbanna since the 1960 s and the application of fertilizers is a major part of plantation management. This study investigated the effects of fertilizer application on soil CO2 emission in rubber plantations in Xishuangbanna. Four treatments were established within a rubber plantation in Xishuangbanna Tropical Botanical Garden：（ i） fertilizer application in spring only,（ ii） fertilizer application in autumn only,（ iii） fertilizer application in both autumn and spring,and（ iv） control（ no fertilization）. Static chamber gas chromatograph was used to monitor CO2 emissions. The results showed that：（ 1） The seasonal pattern of soil CO2 emission was the same under all treatments.（ 2） For all treatments,soil CO2 emissions were higher during the rainy season than during the dry season,and the total annual emissions were 7. 88- 7. 93 t C ·hm-2·a-1.（ 3） Fertilizations produced higher monthly CO2 emissions than no fertilization.（ 4）Fertilizations promoted soil respiration to some extent,and caused an increase in soil CO2 emission,but the differences were not significant（ P 0. 05）. The results of this study revealed soil carbon cycling in rubber plantation and provided a scientific basis for sustainable management of rubber plantations.