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由于气候变化、过度放牧、沟蚀及修路等人为影响,尕海泥炭沼泽地出现退化现象。为了查明尕海泥炭沼泽地退化过程土壤性质和水源涵养功能的变化趋势,采用空间序列代替时间序列的方法,对该区域4种不同退化阶段泥炭沼泽地土壤性质和水源涵养功能进行了调查研究。结果表明:随着尕海泥炭沼泽地退化程度的加剧,0~40 cm层土壤平均容重逐渐增大,总孔隙度逐渐减小,且容重和孔隙度在土壤剖面自然分布规律发生变化;土壤有机质、全氮、速效钾和水解氮含量呈逐渐降低趋势,铵态氮呈增大趋势,全磷、全钾无明显变化规律,但均沿土壤剖面分布呈波动性变化;土壤自然含水量、最小蓄水量和毛管蓄水量均为未退化最大,中度退化最小;方差分析结果表明不同退化阶段泥炭沼泽地土壤容重、总孔隙度、有机质、氨态氮及其土壤蓄水性能均存在显著差异。土壤饱和蓄水量和毛管蓄水量与有机质之间存在显著正相关,并受植被盖度和泥炭层厚度的影响。研究结果表明地下水位、植被盖度、土壤有机质含量及泥炭层厚度的下降是导致尕海泥炭沼泽地退化过程土壤性质和水源涵养功能变化的主要原因。
As a result of climate change, overgrazing, gully erosion and road repairs, man-made impacts have led to degradation of the Gahai peat swamp. In order to find out the changing trend of soil properties and water conservation function in the degradation process of the peat swamp in the sea of Gahai, soil properties and water conservation function of peat swamp at four different degradation stages in the area were investigated by using spatial sequence instead of time series . The results showed that with the aggravation of the degradation of the peat swamp in the sea of Gahai, the average bulk density of 0-40 cm soil layer increased gradually and the total porosity decreased gradually. The natural distribution of bulk density and porosity varied in the soil profile. The contents of soil organic matter , The content of total nitrogen, available potassium and hydrolyzed nitrogen decreased gradually, the content of ammonium nitrogen increased, but there was no obvious change pattern of total phosphorus and total potassium, but all showed a fluctuant variation along the soil profile distribution. The soil natural water content was the smallest The results of ANOVA showed that there were significant differences in soil bulk density, total porosity, organic matter, ammonia nitrogen and soil water storage capacity in peat swamp at different degradation stages difference. There was a significant positive correlation between soil saturated water storage capacity and capillary water storage capacity and organic matter, which was affected by vegetation coverage and peat thickness. The results show that the decrease of groundwater table, vegetation coverage, soil organic matter content and peat layer thickness are the main reasons leading to the changes of soil properties and water conservation functions in the degradation process of the peat swamp in the sea of Gahai.