PDF HTML阅读 XML下载 导出引用 引用提醒 苔藓和凋落物对祁连山青海云杉林土壤呼吸的影响 DOI: 10.5846/stxb201510132067 作者: 作者单位: 兰州大学生命科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金集成项目(91425301) Effects of litter and moss on soil respiration in a spruce forest in the Qilian Mountains, Qinghai Author: Affiliation: School of Life Science,Lanzhou University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 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≤R2≤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(Q10)分别为5.47,3.67,均高于裸土土壤呼吸的Q10(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:Soil respiration (Rs) is an important component of the terrestrial ecosystem carbon cycle and the main pathway for carbon transfer from the ecosystem to the atmosphere. Until recently, research has focused on the relationship between environmental factors and Rs, but the effect of litter and moss on Rs is poorly understood. Litter and moss are common forest-floor components, particularly in northern conifer forests and possibly affect soil respiration by regulating soil temperature, water, and carbon input. Understanding the effect of litter and moss is fundamental to accurately evaluate the global carbon efflux. To evaluate the contribution of litter and moss to total Rs, we selected the Tianlaochi catchment in the Qilian Mountains, Qinghai as our study area. Rs of soil under the spruce forest was observed for three years using an LI-8100 automatic instrument (LI-Cor, Inc, NE, USA). Simultaneously, soil temperature and moisture at a depth of 10 cm were recorded using a temperature probe and moisture sensor on the LI-8100. The results showed Rs had obvious monthly and diurnal variations in growing seasons-the monthly maximum Rs occurred in August and minimum in May, and the daily maximum value occurred at 1300h, except for the moss treatment, whose maximum was at 1500h. There was a significant difference in Rs among the three treatments(P<0.01); however, soil surface relative humidity, water content, soil temperature, and surface temperature did not differ significantly among the three treatments. Rs in soil covered by moss and litter, and that in bare soil, was 3.88, 3.31, and 2.28 μmol m-2 s-1, respectively. Moss and litter increased the soil temperature by 8.13% and 10.24%, respectively, more than that of bare soil. The relationship between temperature and Rs among three treatments was exponential. In addition, the correlation coefficient between Rs and soil temperature was higher than that between Rs and surface temperature. The temperature sensitivity (Q10) of soil covered by moss, litter, and bare soil was 5.47, 3.67, and 2.23, respectively. Rs showed a significant correlation with soil water content (VWC) in the bare soil treatment; when VWC was <34%, Rs increased with increased VWC, and when VWC > 34%, Rs decreased with increased VWC. Rs showed a strong negative relationship with VWC in moss and litter treatments. The contribution rates to Rs by moss and litter were 29.33% and 24.06%, respectively. From the present study, we can conclude that litter and moss are important factors affecting forest ecosystem Rs, and it is fundamental to consider the effect of litter and moss when Rs is calculated in forest ecosystems. 参考文献 相似文献 引证文献