黄土高原不同林龄刺槐林土壤呼吸研究

Research on Soil Respiration in Different Ages of Robinia pseudoacaciain the Loess Plateau

采用LI-8100开路式土壤呼吸仪对不同林龄(10,12,13,16a)刺槐林土壤呼吸速率、温度、水分进行了测定。结果表明:(1)不同林龄刺槐林土壤呼吸速率均呈现明显的日动态和季节动态,表现出夏季>秋季>冬季;(2)各林龄刺槐林土壤呼吸速率与大气温度、地表温度、5cm土壤温度均有很好的指数关系,尤其与5cm土壤温度的相关性最好,且各林龄刺槐林的Q10存在差异,表现为随着林龄的增大,Q10值也随之增大;(3)各林龄刺槐林土壤呼吸速率与土壤体积含水量具有很好的线性关系,且相关性都达到了显著水平(p<0.05);(4)各林龄刺槐林土壤呼吸速率与5cm土壤温度、土壤体积含水量的综合作用也具有很好的相关性,且都达到了极显著水平(p<0.01),二者共同解释了土壤呼吸变异的93.8%~98.1%,且双因素模型远比单因素能够更好地解释刺槐林土壤呼吸速率的变异。

The soil respiration, temperature and moisture in the different forest ages （10, 12, 13, 16 years） of Robinia pseudoacacia were determined by using the LI-8100 open-type soil respiration apparatus. The results showed that： （1） the soil respiration rates in different forest ages of locust forest showed a significant diurnal and seasonal dynamics, and followed the seasonal sequence of summeK〉autumn^winter; （2） there is a good exponential relationship between the three temperatures and the soil respiration rates in different forest ages of locust forest, especially there is the best correlation with soil temperature in 5 cm layer and there are differences in Ql0 between the different forest ages of locust forest, Q10 was associated with the increase of forest ages; （3） a highly significant linear correlations between the soil respiration rate and the soil volumet ric water content in the different forest ages of locust forest were observed（p^0.05） ; （4） the comprehensive effect of soil respiration rate and soil temperature in 5 cm depth and soil volumetric water content in the dif ferent forest ages of locust forest, has a highly significant linear correlation（p^0.01） which can explain soil respiration variation of 93.8% ~98. 1 ~, and two-factor model explaining locust forest soil respiration rate variability is better than single-factor model.