尕海泥炭地退化过程中土壤渗透特征的变化

Soil Infiltration Characteristics During Degradation Process of Peat Wetlands in Gahai

由于恶劣的气候条件和过度的放牧、修建公路等因素,尕海泥炭湿地退化严重,泥炭地质量和生态作用持续下降。本研究采用空间分布代替时间序列的方法,对该区域4种不同退化程度下泥炭湿地土壤渗透性能的变化进行分析研究,从而进一步评价与揭示退化过程中泥炭地的生态功能。结果表明：在前35 min,泥炭地土壤入渗速率曲线在各土壤分层中的变化情况不一;0~10 cm和20~40 cm土层土壤入渗速率曲线变化稳定且都表现为未退化的优于退化土壤;而10~20 cm土层土壤入渗速率曲线变化复杂多变,无明显规律。0~40 cm泥炭土中,植被退化对各层土壤渗透特征的影响不一,在0~10 cm土层,植被未退化土壤的初渗率、稳渗率、平均渗透速率、渗透系数和渗透总量与其他退化土壤渗透特征差异性显著;10~20 cm土层,未退化的土壤稳渗率、渗透速率、渗透系数与渗透量随着植被的退化程度呈“∽”形态波动变化;0~40 cm土层,土壤稳渗率、平均渗透速率、渗透系数和渗透总量均随着植被的退化,呈现出逐级递减的规律。土壤平均渗透速率与土壤孔隙度呈一定的正显著相关,而与土壤初始含水量之间无明显的相关性。保护高寒泥炭地生态系统,对于尕海畜牧业可持续发展和我国陆地生态系统碳库具有极重要的意义。

Due to bad climatic conditions and other factors such as overgrazing, building roads, etc. the peat wetland in Gahai degraded seriously, the quality and ecological function of peatlands declines gradually. This study by adopting the method of spatial distribution replacing time-sequence, analyzed the change of soil infiltration and ecological function under four different degradation degrees of the peat wetlands. The results showed that during the first 35 minutes, soil infiltration rate changed differently in different soil layers; soil infiltration rates in 0-10 cm layer and 20-40 cm layer changed stably, and soil infiltration rates were higher in degraded soils than non-degraded one, while soil infiltration rate in 10-20 cm layer changed irregularly. The influences of vegetation degradation on soil infiltration characteristics in different layers within 0-40 cm depth of the peat wetlands were different. In 0-10 cm layer, the initial infiltration rate, the steady infiltration rate, the average infiltration rate, infiltration coefficient and total infiltration of non-degraded peat wetland were different significantly with degraded peat wetlands; in 10-20 cm layer, the steady infiltration rate, the average infiltration rate, infiltration coefficient and total infiltration of non-degraded peat wetland changes in ＂~＂ form; in 0-40 cm layer, the steady infiltration rate, the average infiltration rate, infiltration coefficient and total infiltration declined with the degradation of vegetation. The average infiltration rate had significant positive correlation with soil porosity, but had no significant correlation with soil initial moisture. The protection of alpine peatland ecosystem is essential for the sustainable development of Gahai animal husbandry and the carbon strage of China terrestrial ecosystem.