太行山南段刺槐林地土壤酶活性季节变化特征

Seasonal dynamics characteristics of soil enzyme activities of Robinia pseudoacacia in southern Taihang Mountains

本研究以农田为对照,研究了太行山南段退耕还林刺槐林地土壤酶活性的季节变化特征,探讨影响该区土壤酶活性的关键化学影响因子。结果表明:各样地酶活性季节动态变化差异显著,不同林龄的刺槐林地土壤纤维素酶、蔗糖酶、脲酶、磷酸酶和过氧化氢酶的活性显著高于农田,但10 a刺槐的蔗糖酶和脲酶活性除外。10 a和43 a刺槐林地的四季土壤酶指数均值较农田分别提高了75.37%和127.80%,43 a刺槐林地四季土壤酶指数均值较10 a刺槐林地提高了29.90%,表明退耕还林种植刺槐能够显著提高土壤的生物活性,且植被恢复时间越长,效果越显著。逐步回归分析表明,纤维素酶、蔗糖酶和磷酸酶活性的主要化学影响因子之一是速效钾,脲酶活性的主要化学影响因子是速效磷,过氧化氢酶活性的主要化学影响因子则是硝态氮和有机质。

The seasonal variation characteristics of soil enzyme activity in Robinia pseudoacacia land of returning farmland to forests were studied and the key chemical factor influencing soil enzyme activity were discussed. This paper was based on the farmland for comparison in southern Taihang Mountains.The results showed that： the seasonal dynamic changes were significantly different. Except invertase and urease of RP10,the soil cellulase,invertase,urease,phosphatase and catalase activity in Robinia pseudoacacia forest＇s land of different tree-age were significantly higher than that of farmland. The soil enzyme index mean of RP10 and RP43 was increased by 75. 37% and 127. 80% compared with the farmland in four seasons,respectively. The soil enzyme index mean of RP43 was increased by 29. 90%compared with the RP10 in four seasons. The results indicate that planting Robinia pseudoacacia in re-turning farmland to forest area could significantly improve the soil biological activity,and the longer the vegetation restoration is,the more significant the effect is. Stepwise regression analysis showed that one of the main chemical factor influencing cellulase,invertase and phosphatase was available K,and the main chemical factors influencing available were available P,the main chemical factors influencing catalase were ammonium-N and organic matter.