摘要
基于气体红外分析技术,在华北低丘山地退耕还林区内,以农田、撂荒地为对照,分析退耕43年和退耕10年刺槐人工林土壤呼吸速率的季节变化及其环境影响机制。结果表明:退耕43年和退耕10年刺槐人工林0～5 cm土层的土壤有机质含量分别是农田的3.9和1.6倍;退耕43年刺槐人工林、退耕10年刺槐人工林、撂荒地和农田的全年土壤呼吸平均速率分别为2.33,1.21,2.40和2.04μmol·m-2s-1,其中撂荒地的全年土壤呼吸平均速率最大,退耕43年刺槐林的全年土壤呼吸平均速率大于退耕10年刺槐林;研究区内4种土地条件下的土壤呼吸速率主要受5 cm深处土壤温度影响,退耕43年刺槐林、退耕10年刺槐林、撂荒地及农田的土壤呼吸温度敏感系数Q10分别为2.47,2.53,2.06和1.56,其中2种退耕林地的Q10均显著高于农田;4种土地利用条件下的Q10均存在显著的季节变异,其大小主要受温度影响。退耕还林工程的实施显著改善了土壤固碳能力。
In this study, seasonal variations in soil respiration rate （R） in 43-year-old and l O-year-old Robinia pseudoacacia plantations, abandoned land and cropland, and the influence mechanisms were investigated in hilly area of northern China. In 0 -5 cm layers, soil organic matter content of 43-year-old and 10-year-old R. pseudoacacia plantations was 3. 9 and 1. 6 times of cropland, respectively. Annual soil respiration rates of 43-year-old and 10-year-old R. pseudoacacia plantations, abandoned land and cropland were 2.33, 1.21, 2.40, and 2.04 μmol · m-2 s-1, respectively. The cropland had the highest annual R, and the annual R of 43-year-old R. pseudoacacia plantation was significantly higher than that of lO-year-old R. pseudoacacia plantation. Regression analysis showed that soil temperature was the main environmental factor affecting the seasonal variation of R. The temperature sensitivity （ Q10 ） of soil respiration was 2.47, 2.53, 2. 06, and 1.56 for 43-year-old and 10-year-old R. pseudoacacia plantations, abandoned land, and cropland, respectively. Compared to the cropland, two plantations presented a more temperature sensitivity of soil respiration. Moreover, there was a significant seasonal variation in Q10 in the four land uses, and soil temperature was the key factor that affected the temperature sensitivity of soil respiration. The results indicated that sequestration capacity of soil organic carbon was improved in the two plantations.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2014年第2期1-7,共7页
Scientia Silvae Sinicae
基金
"十二五"国家科技支撑计划项目(2011BAD38B06)
关键词
土壤呼吸
Q10
退耕还林工程
华北低丘山地
soil respiration
Q,o
grain-for-green program
, hilly area of northern China
