Abstract:

In order to investigate soil seasonal gleization process in the alpine meadow on the Tibetan plateau, the soil gleization and its two main controls (high soil organic carbon content (SOC) content and anaerobic environment) were reported in the alpine grassland from Dec. 2013 to March 2014. The results show that the soil seasonal gleization occurres in the humus layer with blue-gray iron and manganese plaques. The soil seasonal gleization occures during the period of soil freezing and thawing, and a positive relationship between the thickness of gleization layer and frozen layer is observed. The process is pseudogley at mild level, with decreasing soil microbial biomass carbon, and increasing cation exchange capacity (CEC), active Fe²⁺, Mn²⁺ and availble phosphuros. The reults suggest that soil gleization may subsequently affect microbial community, root mortality, greenhouse gas emmission and nutrient cycling. Although soil gleization appears in the non-growing season, its impacts on the soil ecological processes should not be ignored.

Key words: soil gleization, alpine grassland, soil freezing and thawing

摘要：

为了探究青藏高原高寒草甸非水成化土壤是否发生潜育化, 在2013年12月至2014年3月非生长季的野外观测过程中, 发现青藏高原东北部高寒草甸非水成化土壤存在季节性潜育化, 主要由较高的有机质含量以及土壤季节性冻融产生的厌氧环境造成。在土壤腐殖质层观察到铁锰结核和胶膜层, 呈蓝灰色, 潜育类型属于轻潜型和假潜育型。通过分析得出, 土壤潜育化主要发生在土壤季节性冻融期间, 潜育层厚度与冻融层厚度之间显著正相关。2014年1月的取样分析结果显示, 潜育化显著降低微生物生物量碳, 提高了活性态铁锰含量、阳离子交换量和有效磷含量。季节性潜育化可能对冻融过程中微生物群落结构、根系动态、温室气体排放以及养分循环等方面产生重要影响。由于潜育化只发生在非生长季, 这一现象容易被忽略, 但其对土壤生态过程产生的影响值得关注。

关键词: 潜育化, 高寒草甸, 土壤冻融过程