固沙植被区典型生物土壤结皮类型下土壤CO2浓度变化特征及其驱动因子研究

 对固沙植被区典型分布的藻类结皮、藓类结皮和流沙下不同深度的土壤气体采样,主要研究和讨论了不同类型生物土壤结皮下土壤CO2浓度的变化特征,及土壤温度和土壤水分对它的影响。结果表明,藻类结皮和藓类结皮在0~40 cm处的土壤空气CO2浓度平均值基本保持在600~1 100 μmol·mol-1之间,大于同一深度流沙下土壤CO2浓度值,但三者之间的差异并不显著。土壤温度与土壤CO2浓度呈正相关关系,且在表层相关性最强,具体表现为流沙>藓类结皮>藻类结皮。土壤水分对土壤CO2浓度的影响在表层0~5 cm为流沙>藻类结皮>藓类结皮,但在下层10~40 cm处为藻类结皮>藓类结皮>流沙。

Soil CO_2 Concentration under Different Types of Biological Soil Crusts and Its Driving Factors in the Sand-fixed Vegetation Zones

Soil CO2 emission fluxes under algae crust, moss crust and shifting sand at different soil depths in the sand-fixing vegetation zones were observed using the CO2 profile test method. The distribution characteristics of CO2 concentration and the impact of soil temperature and soil moisture on CO2 concentration under different soil crusts were analyzed. Results showed that the variation range of soil CO2 concentration under algal crust and moss crust at 0-40 cm soil layer was 600-1 100 μmol·mol-1, large than at the same depth of shifting sand, but the difference was not significant. Soil temperature was positively correlated with the soil CO2 concentration, especially in the topsoil, and the order was shifting sand>moss crust>algae crust. The influence of soil moisture on soil CO2 concentration in the topsoil of 0-5 cm soil layer was shifting sand>algal crusts>moss crust, but at 10-40 cm soil layer the order was algae crust>moss crust>shifting sand.