苔藓和凋落物对祁连山青海云杉林土壤呼吸的影响

发布时间：2018-12-26 17:03

【摘要】：于2012—2014年生长季在青海云杉林下开展了地表覆盖物(苔藓和凋落物)对林下土壤呼吸速率影响的研究。采用LI8100土壤碳通量自动测量系统对苔藓覆盖、凋落物覆盖和裸土(去除地表覆盖物)的土壤呼吸进行观测,对比分析林下3种覆盖处理下的土壤呼吸差异。结果表明:苔藓覆盖土壤、凋落物覆盖土壤和裸土土壤的呼吸速率年均值分别为(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),三者之间具有极显著差异,3组处理的地表相对湿度、土壤含水量、土壤温度和地表温度间均没有显著差异,但苔藓组和凋落物组的土壤温度分别比裸土组高8.13%和10.24%;3组处理的土壤呼吸速率均与温度呈显著指数相关性(0.53≤R~2≤0.91),且与土壤温度的相关性更高;苔藓覆盖、凋落物覆盖土壤呼吸的温度敏感性(Q_(10))分别为5.47,3.67,均高于裸土土壤呼吸的Q_(10)(2.23);裸土土壤呼吸与土壤含水量(VWC)呈高斯函数关系,VWC=34%是临界值,苔藓覆盖、凋落物覆盖土壤的呼吸速率与土壤含水量均呈线性负相关关系;苔藓和凋落物对裸土土壤呼吸的月均贡献率分别为29.33%和24.06%,可见,苔藓和凋落物在青海云杉林生态系统呼吸中起重要作用。
[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 卤0.26) 渭 mol m-2 s-1), (3.31 卤0.19 渭 mol m-2 s-1, respectively. (2. 28 卤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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