增温对亚热带森林土壤呼吸变化的影响

目的]研究增温条件下亚热带森林土壤呼吸的变化。方法]以福建省亚热带杉木林为对象,通过埋设加热电缆的方法开展亚热带模拟土壤增温试验,采用13C脉冲标记技术,高效追踪土壤气体的变化情况。结果]在试验期间,增温后土壤总呼吸、异养呼吸的δ13C均高于对照组,δ13C先下降后上升,然后继续下降,与初始状态持平;增温后土壤总呼吸速率与异养呼吸速率变化趋势基本一致,且异养呼吸速率与其对应的δ13C的相关性大于土壤呼吸与其对应的δ13C的相关性。因而,在气候变暖条件下,增温对土壤中的微生物以及根系造成影响,导致土壤呼吸以及异养呼吸变化会有较大的浮动。结论]该研究为进一步了解增温后亚热带森林地区土壤呼吸的变化提供了一定的参考依据。

Effect of Increasing Temperature on Soil Respiration of Subtropical Forest

Objective]The aim of this study was to study the change of soil respiration in subtropical forest under the condition of increasing temperature.Method]Taking the subtropical Chinese fir forest in Fujian Province as an example,the simulated soil temperature increase experiment was carried out by burying heating cable.The 13C pulse labeling technology was used to track the change of soil gas effectively.Result]During the experiment,theδ13C of total respiration and heterotrophic respiration of soil after increasing temperature were higher than that of the control group.Theδ13C decreased first,then increased,and then continued to decline,which was the same as the initial state.The change trend of soil total respiration rate and heterotrophic respiration rate was basically the same after increasing temperature,and the correlation between heterotrophic respiration rate and its correspondingδ13C was greater than that between soil respiration and its correspondingδ13C.Therefore,under the condition of climate warming,the increase of temperature had an impact on the microorganism and root system in the soil,which led to the fluctuation of soil respiration and heterotrophic respiration.Conclusion]This study provided a reference for further understanding the changes of soil respiration in subtropical forest areas after warming.