Abstract: Land management has a significant influence on soil CO₂ emission. Rubber trees have been planted in Xishuangbanna since the 1960s 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.

Key words: genetic diversity, habitat condition, microsatellite markers, South Anhui