北京山区辽东栎林土壤释放CO_2的模拟实验研究

A STUDY ON THE MEASUREMENT OF CO 2 EMISSION FROM THE SOIL OF THE SIMULATED Quercus Liaotungensis FOREST SAMPLED FROM BEIJING MOUNTAIN AREAS

模拟北京山区辽东栎林群落，对该类型土壤释放ＣＯ２过程进行了连续３ａ的实验研究，结果表明：辽东栎林土壤呼吸强度平均为５．９２±１．３２μｍｏｌＣＯ２ｍ－２ｓ－１，在不同月份中，以８月份最高，１０月最低，依次为８月＞７月＞６月＞９月＞１０月（Ｐ＜０．０５）；１３：００为土壤日呼吸的最高峰。温度为影响土壤呼吸的主要因子，二者存在极显著相关关系（ｒ＝０．５６６８，ｐ＜０．００１，ｎ＝９４）。据３ａ观测的土壤呼吸日平均值计算得出，模拟辽东栎林土壤释放ＣＯ２的通量估计范围为１７１．５～２７５．１ｋｇＣＯ２ｈｍ－２ｄ－１，平均为２２３．３ｋｇＣＯ２ｈｍ－２ｄ－１。

The simulated Quercus liaotungensis was planted and the soil respiration was measured,the soil and trees of Quercus liaotungensis and some grass species being sampled from a deciduous forest in Beijing mountain areas.The three year's experiments showed that the soil respiration of Quercus liaotungensis forest averaged 5.92±1.32μmol CO 2m -2 s -1 ,in which the highest appeared in August,while the lowest in October.The series of soil respiration was arranged:August>July>June>September>October(P<0.05).During the daytime,there was a peak value of soil respiration around 13:00 O'clock.There existed a good linear correlation between soil respiration and ground temperature(r=0 5668,P<0 001,n=94).Based on the three year measurement,the soil CO 2 flux was estimated that the range of flux was 171.5～275.1kg CO 2 hm -2 d -1 ,and average value 223 3kg CO 2 hm -2 d -1 .