杉木人工林土壤呼吸日变化及其影响因素分析

Soil Respiration and Its Influencial Factors in China fir Plantation on Different Ground Utilizations

通过野外定点监测,对杉木抚育林、杉木撂荒林和林外草地的土壤呼吸日变化及其影响因素进行了研究.结果表明：不同土地利用条件下杉木人工林土壤呼吸速率的日变化均呈单峰曲线,抚育林和撂荒林最高值出现在16：00,林外草地最高值出现在12：00,土壤呼吸速率的最低值均出现在04：00;林外草地各时刻的土壤呼吸速率均比抚育林和撂荒林高;土壤呼吸递减速率在20：00-00：00间抚育林比撂荒林慢,在00：00-04：00抚育林比撂荒林快;土壤温度与土壤呼吸速率的相关性均达到了显著水平（p〈0.05）,土壤含水率与土壤呼吸速率的相关性不显著（p〉0.05）;以土壤5 cm处温度为依据得到的温度系数（Q10值）大小排序为林外草地〉撂荒林〉抚育林.

On different ground utilizations, the daily changing of soil respiration velocity takes on single apex curves. The highest value of soil respiration for foster and fallow fields appears on 16：00; that for grassplots on 12：00. The lowest mean value of soil respiration for all three appears on 04：00. The soll respiration velocity for grassplots is higher than that for foster and fallow fields on each time point. Between 20：00 and 00：00, the descending of respiration velocity for foster fields is slower than that for fallow fields, but between 00：00 and 04 ：00, the situation is just reversed. The relativity of soil temperature and soil respiration is remarkable while the relativity of soil water content and soil respiration is not remarkable. Based on the temperature at 5 cm soil, the order of the Q10 value is ： grassplot〉fallow field〉foster field.