禁牧对高原湿地纳帕海退化草甸土壤理化性质的影响

Effect of Grazing Prohibition on Soil Properties of Degraded Meadow in Napahai Plateau Wetland

2012年采用比较研究法对高原湿地纳帕海禁牧4年、禁牧8年和未禁牧的退化草甸土壤理化性质进行调查分析,探索禁牧对高原湿地退化草甸土壤理化性质的影响。结果表明,禁牧显著降低了土壤容重值,增加了土壤毛管持水量,改善了土壤物理性质,且禁牧时间越长,效果越显著;随着禁牧时间的增加,土壤有机碳、全氮、碱解氮、速效磷含量逐渐递增,且表层0～20 cm土壤比深层20～40 cm土壤变化幅度大;纳帕海湿地退化草甸土壤理化性质随着禁牧时间的增加趋于良性循环,并与植物生长和植被演替有着密切关系,表明禁牧是高原湿地退化草甸土壤恢复的有效措施。

Soil physical-chemical properties of non-grazing for 4 years meadow, non-grazing for 8 years meadow and grazing meadow in Napabai plateau wetland were examined and compared in 2012, aiming to find out the effect of grazing prohibition on soil recovery of degraded meadow. The results showed that grazing prohibition significantly reduced the soil bulk density, increased water holding capacity and improved soil physical properties. The longer the grazing prohibition lasted, the more notable effect was. With the increment of grazing prohibition period, soil organic carbon, total nitrogen, available nitrogen and available P gradually increased, and surface soil （0 -20 em） changed more than deep soil （20 ~ 40 em）. Physical-chemical properties of degraded meadow became a virtuous cycle with the increment of grazing prohibition period in Napahai plateau wetland and had close relation with plant growth and vegetation succession. It was proved that grazing prohibition was an effective measure to recover the soil of degraded meadow in plateau wetland.