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以中亚热带马尾松林和苦槠林为对象,原位收集根际和非根际土壤、树木不同生态功能的根系,开展15℃、25℃、35℃和45℃恒温培养模拟试验,采用密闭气室碱液吸收法测定53d内CO2释放的动态变化.结果表明:两种森林类型不同温度下土壤矿化CO2释放速率的根际效应介于1.12～3.09,且培养前期高于培养后期;15℃下马尾松林和苦槠林差异不显著,25℃和35℃下前者低于后者,45℃下则相反.不同培养温度下两树种吸收根分解的CO2释放速率均高于过渡根和贮存根,且马尾松均低于苦槠.两种森林类型CO2释放的Q10值均为土壤(1.21～1.83)显著高于根系(0.96～1.36).两种森林类型土壤矿化CO2释放的Q10值差异不显著,而马尾松根系分解CO2释放的Q10值高于苦槠.推断全球变暖导致的土壤矿化CO2释放的增量将远远高于根系分解,且马尾松林高于苦槠林;地带性顶极群落应对气候变化的抵抗力强于先锋树种群落.
In order to collect the roots of rhizosphere and non-rhizosphere soils and trees with different ecological functions, the simulation experiments of 15 ℃, 25 ℃, 35 ℃ and 45 ℃ were carried out in the Central Asian subtropical masson pine and bitter mire forests. The results showed that the rhizosphere effect of CO2 emission rate of soil mineralization was between 1.12 and 3.09 at different temperatures and higher at the early stage of culture than at the later stage of culture. There was no significant difference between Pinus massoniana and Castanopsis kawakamii under the conditions of 25 ℃ and 35 ℃, while the former was lower than the latter at 45 ℃ .The CO2 release rate of roots under different culture temperature was higher than that of the transitional roots and storage roots , And the mass percentages of Pinus massoniana were lower than those of bitter grub.The Q10 values of soil CO2 emission from both forest types were significantly higher than those from the root system (1.21-1.83) (0.96-1.36) But the Q10 value of Pinus massoniana root decomposition CO2 release was higher than that of bitter grub.It is inferred that the increment of CO2 emission from soil mineralization caused by global warming will be much higher than that of root decomposition and the Pinus massoniana forest is higher than that of bitter tress forest; Sexual climax communities are more resilient to climate change Pioneer tree species community.