Dynamics Of Soil Respiration In An Oak Secondary Forest And A Pine Plantation In Southeastern China

Soil respiration is an important component in carbon cycle of the terrestrial ecosystem. With global warming, the response of soil respiration to it has been an important study field in global change issue. The object of this paper is to understand variation of soil respiration and its mechanism in an oak forest and a pine plantation in southeastern China, so as to provide basic data for estimation of carbon budget and prediction of global change in the future. I conducted the experiment to examine the diurnal, monthly and interannual variation of soil respiration, and to examine the effects of soil temperature, soil moisture, soil microbial biomass and litterfall on soil respiration in a secondary oak forest and pine plantation at Xiashu Experimental Site in Jiangsu province, southeastern China. I applied the dynamic-chamber IRGA method (Li-6400) and Alkali Absorption (AA) to measure the soil respiration and compared to understand their relationship. Moreover, Li-8100 was used to observe diurnal soil respiration. Two treatments (Litter removal and Control) with four repeated plots in each forest were set up, respectively. The results showed that soil respiration varied diurnally and monthly in both oak and pine forest. In a year, soil respiration peaked summer (July or August), when temperature is relatively high, and minimized the respiration rate in winter (January), when the temperature is relatively low. The diurnal variations varied in different months and forests. There was no significant interannual variation of soil respiration in the two forests. Moreover, there was no significant difference of soil respiration between the oak forest and pine plantation. My results indicated that temperature and litterfall affected substantially on soil respiration in the two forests. The relationships between soil respiration...