【摘要】 近年来,在不合理人类活动和气候变化的共同作用下,若尔盖地区高寒草甸沙化日趋严重,草地生态系统遭到严重破坏。土壤承载着植物、微生物和土壤动物等的生命活动,研究其理化性质、酶活性及二者的关系对草地生态系统的保护和恢复具有重要意义。本研究在若尔盖地区沙化草地设置样地,收集植物群落信息、采集土壤样品、分析土壤理化性质和酶活性,探讨不同沙化梯度下高寒退化草地的土壤理化性质和酶活性动态特征及其之间关系。结果发现:随着沙化程度的加剧,土壤容重、pH和碱性磷酸酶活性呈增加趋势,土壤6种营养元素(有机碳、全碳、速效氮、全氮、速效磷和全磷)及脲酶、木质素过氧化物酶、β-葡萄糖苷酶和N-乙酰-β-D-葡萄糖苷酶呈递减趋势;土壤pH与碱性磷酸酶呈显著正相关关系(P<0.01),与木质素过氧化物酶、β-葡萄糖苷酶和N-乙酰-β-D-葡萄糖苷酶均呈显著负相关关系(P<0.01)。碱性磷酸酶与木质素过氧化物酶和β-葡萄糖苷酶均呈显著线性负相关关系(P<0.01,R~2=0.27;P<0.05,R~2=0.17),碱性磷酸酶活性的增加对木质素过氧化物酶和β-葡萄糖苷酶有一定的抑制效应。木质素过氧化物酶与β-葡萄糖苷酶和N-乙酰-β-D-葡萄糖苷酶均呈显著线性正相关关系(P<0.01, R~2=0.59;P<0.01,R~2=0.26),木质素过氧化物酶活性的增加对β-葡萄糖苷酶和N-乙酰-β-D-葡萄糖苷酶有一定的促进作用,它们之间存在一定的协同关系。该研究为进一步探索若尔盖地区草地沙化土壤酶活性机理提供了科学依据和重要的参考价值。更多还原

【Abstract】 Desertification resulting from intensive human activities and climate change has become increasingly severe.Consequently, it is important to study soil physical and chemical properties and enzyme activity for the protection and restoration of grassland ecosystems. In this study, we observed plant community characteristics and analyzed soil physical and chemical properties and enzyme activities along a transect(from more to less degraded) in the Zoige alpine meadow ecosystem. As the degree of degradation increased, the soil bulk density, pH and the alkaline phosphatase(S-ALP) activity also increased, while soil organic carbon, total carbon, available nitrogen, total nitrogen, available nitrogen, total phosphorus,and activities of urease(S-UE), lignin peroxidase(S-Lip), β-glucosidase(S-β-GC) and N-acetyl-β-D-glucosidase(S-NAG)decreased. Soil pH was positively correlated with S-ALP(P<0.01), and negatively correlated with S-Lip, S-β-GC and(SNAG)(P<0.01). S-ALP was negatively and linearly correlated with S-Lip(P< 0.01, R~2=0.27) and S-β-GC(P< 0.05,R~2=0.17), indicating that increased S-ALP activity has some inhibitory effect on S-Lip and S-β-GC. Moreover, S-Lip was positively and linearly correlated with S-β-GC(P<0.01, R~2=0.59) and S-NAG(P<0.01, R~2=0.26), suggesting that S-Lip could promote S-β-GC and S-NAG activities. The findings provide a scientific basis and important reference for further exploration of the dynamics of soil enzyme activity in grassland desertification, Zoige region.更多还原