摘要
2010年生长季,采用不同处理(去凋切根、去除凋落物、对照、切除根系、加倍凋落物)研究土壤C源输入方式对油松人工林土壤呼吸速率及5 cm土壤温湿度的影响。结果表明:改变C源输入对土壤温度产生的差异不显著(P>0.05),而对土壤湿度和土壤呼吸速率产生的差异显著(P<0.05)。整个观测期去凋切根、去凋、对照、切根及加倍凋落物处理的土壤呼吸速率平均值分别为1.54,1.71,2.71,2.47!mol m-2s-1和3.39!mol m-2s-1。相比对照样方土壤呼吸,去凋切根处理使油松人工林整个观测期土壤呼吸速率平均降低(44.27±2.31)%;去除凋落物使土壤呼吸速率平均降低(36.03±2.64)%;切除根系使土壤呼吸速率平均降低(10.76±3.26)%,但试验初期切除根系表现为增加土壤呼吸,6月下旬和7月中旬分别使土壤呼吸增加25.91%和0.29%,此后,切除根系使土壤呼吸速率显著降低。如果排除6月和7月的数据,则切除根系使土壤呼吸速率平均降低21.90%;加倍凋落物使土壤呼吸速率平均增加(21.01±3.21)%。去凋切根、去凋、切根和加倍凋落物处理土壤呼吸的温度敏感系数Q10值分别为1.75,1.65,2.32和3.10,四者之间差异均显著(P<0.05),对照样方土壤呼吸的Q10值为2.23。不同处理土壤呼吸速率与土壤温度均呈显著指数相关(P<0.001),而与土壤湿度的相关性并不显著(P>0.05)。土壤温度和水分的双变量模型均可以很好地解释土壤呼吸的季节变化,拟合方程的R2值范围为0.49—0.83。
In recent years, much attention has been paid to soil respiration due to its important role in the carbon cycle of terrestrial ecosystems. Five treatments involving a） both litter and root exclusion, b） only litter exclusion, c） a control, d） only root exclusion and e） litter addition were applied to analyze the relationship between changes of carbon input and soil respiration. In addition, soil temperature and moisture effects were studied in a Pinus tabulaeformis plantation. The results showed that there were similar respiration curve with seasons in different treatments. The average soil respiration rates for the treatments a） to e） were 1.54, 1.71, 2.71, 2.47 and 3.39 ~mol m-2 s-1, respectively. On average, the soil respiration was significantly decreased by both litter and root exclusion, about （44.27 ±2.31 ）% lower than the control. The soil respiration rate with only litter exclusion was （36.03 ±2.64） % and with only root exclusion was （ 10.76 ±3.26 ） % lower than the control. However, the soil respiration rates with only root exclusion were higher than those of the control for 1-2 months after trenching. The soil respiration rates in late June and mid-July were 25.91% and 0.29% higher thanthose of the control. When the data of June and July were removed, only root exclusion decreased soil respiration by about 21.90%. Soil respiration was significantly increased by litter addition, about （21.01± 3.21 ）% higher than the control. The Qm values were increased in the treatments of only root exclusion （2.32） and litter addition （3.10） relative to the control （2.23）, whereas, these values were decreased in the treatments of both litter and root exclusion （1.75） and only litter exclusion （ 1.65 ）. The relationships between soil respiration and soil temperature at 5 cm depth could be described by an exponential equation, with a determination coefficient （R2 ） of 0.41,0.45, 0.57, 0.64 and 0.73, respectively for the treatments a） to e）, respectively. There was no significant correlation between soil respiration and soil moisture at 5 cm depth. In order to predict both the soil moisture and soil temperature dependency four two-variable linear/non-linear models were developed and evaluated. By use of those models it was possible to predict the soil respiration as a function of both temperature and moisture, with R2 values ranging from 0.49 to 0.83.
出处
《生态学报》
CAS
CSCD
北大核心
2012年第9期2768-2777,共10页
Acta Ecologica Sinica
基金
国家林业公益性行业科研专项项目(20110400903
200904022)
华北区(北京
河南
山西)主要森林类型净生产力多尺度长期观测与评价(200804006/rhh-02)
关键词
油松人工林
土壤呼吸
C源输入
变化幅度
Q10值
Pinus tabulaeformis plantation
soil respiration
carbon input
fluctuation percent
Q10 value
作者简介
通讯作者:赵秀海.E-mail:zhaoxh@bjfu.edu.cn
