【摘要】：于2012—2014年生長季在青海云杉林下開展了地表覆蓋物(苔蘚和凋落物)對林下土壤呼吸速率影響的研究。采用LI8100土壤碳通量自動測量系統(tǒng)對苔蘚覆蓋、凋落物覆蓋和裸土(去除地表覆蓋物)的土壤呼吸進行觀測,對比分析林下3種覆蓋處理下的土壤呼吸差異。結果表明:苔蘚覆蓋土壤、凋落物覆蓋土壤和裸土土壤的呼吸速率年均值分別為(3.88±0.26)μmol m~(-2)s~(-1),(3.31±0.19)μmol m~(-2)s~(-1),(2.28±0.31)μmol m~(-2)s~(-1),三者之間具有極顯著差異,3組處理的地表相對濕度、土壤含水量、土壤溫度和地表溫度間均沒有顯著差異,但苔蘚組和凋落物組的土壤溫度分別比裸土組高8.13%和10.24%;3組處理的土壤呼吸速率均與溫度呈顯著指數(shù)相關性(0.53≤R~2≤0.91),且與土壤溫度的相關性更高;苔蘚覆蓋、凋落物覆蓋土壤呼吸的溫度敏感性(Q_(10))分別為5.47,3.67,均高于裸土土壤呼吸的Q_(10)(2.23);裸土土壤呼吸與土壤含水量(VWC)呈高斯函數(shù)關系,VWC=34%是臨界值,苔蘚覆蓋、凋落物覆蓋土壤的呼吸速率與土壤含水量均呈線性負相關關系;苔蘚和凋落物對裸土土壤呼吸的月均貢獻率分別為29.33%和24.06%,可見,苔蘚和凋落物在青海云杉林生態(tài)系統(tǒng)呼吸中起重要作用。
[Abstract]:The effects of ground cover (moss and litter) on soil respiration rate under Picea crassifolia forest were studied in the growth season of 2012-2014. The soil respiration of moss mulch, litter cover and bare soil (removing ground cover) was observed by LI8100 soil carbon flux automatic measurement system, and the difference of soil respiration under three kinds of mulching treatments was compared and analyzed. The results showed that the annual mean respiration rates of mossy covered soil, litter covered soil and bare soil were (3.88 鹵0.26) 渭 mol m-2 s-1), (3.31 鹵0.19 渭 mol m-2 s-1, respectively. (2. 28 鹵0. 31) 渭 mol m2 s ~ (-1). There was no significant difference in surface relative humidity, soil water content, soil temperature and surface temperature among the three groups. But the soil temperature of moss group and litter group were 8.13% and 10.24% higher than that of bare soil group respectively. The soil respiration rate of the three groups showed a significant exponential correlation with temperature (0.53 鈮，

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