---

作 者 ：王光军,田大伦,朱凡,闫文德,李树战

期 刊 ：生态学报 2008年 28卷 9期 页码：4107~4114

关键词：湖南；土壤呼吸；土壤温度；土壤含水量；Q10值；

Keywords:Hunan, soil respiration, temperature, moisture, Q10 value,

摘 要 ：2007年1月至12月，采用LI-COR-6400-09气室连接到LI-COR-6400便携式CO2/H2O分析系统测定枫香(Liquidambar formosana)和樟树(Cinnamomum camphora)人工林的土壤呼吸，并分析了土壤水热因子及其根生物量对土壤呼吸的影响。研究结果表明：枫香和樟树人工林中土壤呼吸的季节动态存在明显的季节性变化，都呈现不规则的曲线格局。全年土壤呼吸速率平均值分别为1.501 μmol·m-2·s-1和2.800 μmol·m-2·s-1。枫香和樟树林土壤呼吸的季节变化与土壤温度呈显著的指数相关，土壤温度可以分别解释土壤呼吸变化的92.7%和774%，与土壤含水量呈二次方程关系，土壤含水量可以解释土壤呼吸变化的10.6%和18%。在P＝0.05水平上多元回归分析，分别得出枫香和樟树土壤呼吸与土壤温度和含水量方程：y=0.4728e0.122tw0.002； y=0.061e0.235tw0.086，土壤温度和含水量共同可以解释土壤呼吸变化的94.5%和88.5%。枫香和樟树林中全年土壤呼吸的Q10值分别为2.62和3.26，Q10值在随着季节温度升高，而逐渐减小。两种人工林群落土壤呼吸季节变化表现出受非生物因子温度和水分变化的调控，同时也受森林植被的根生物量、凋落物量的影响。

Abstract:Seasonal variations of soil respiration in two forest types, Sweetgum（Liquidambar formosana) and Camphortree (Cinnamomum camphora) plantations, were measured in Tianjiling National Forestry Park of Changsha, Hunan, China. CO2 effluxes rate was monitored using an infrared gas exchange analyzer (LI-COR-6400-09) from January to December 2007, and the controlling factors, such as soil temperature and moisture were also recorded in the two forests. The results showed that the two plantations had significant different patterns in seasonal soil respiration processes. The two forests exhibited irregular fluctuated curves during the study period with mean rates of soil respiration were 1.501 μmol·m-2·s-1 and 2.800 μmol·m-2·s-1 in Sweetgum and Camphortree stands, respectively. Significant relationships were found between soil respiration rate and soil temperature at 5 cm soil depth in both plantations, which could be best described by exponential equations. However, not significant relationships were found between soil respiration and soil moisture at 5 cm depth. Soil temperature and moisture could explain changes in soil respiration of 92.7%, 77.4% and 10.6%, 18.0%, in the Sweetgum and Camphortree plantations, respectively. The relationship between both soil respiration rate (y) and the two variables of soil temperature (t) and soil moisture (w) at 5 cm soil depth could be described by the following multiple regression equation: y=0.4728e0.122tw0.002(R2=0.945, P<00001),y=0.061e0.235tw0.086(R2=0.885, P<0.001). The multiple equations had much more predicative power than those using only temperature or moisture as a single independent variable. The Q10 values in Sweetgum and Camphortree forests were 2.62 and 3.26, respectively, and tended to decrease when soil temperature increased from lower to higher scales. The seasonal patterns of soil respiration in these two forests were not only determined by soil temperature and soil moisture, but also by the fine root mass and litter production as well.

---