放牧对张家界索溪峪景区土壤酶活性及微生物作用强度的影响

Effect of Grazing on Soil Microbial and Enzyme Activities in Zhangjiajie Suoxiyu Scene

采用室外现场采样及室内培养测试方法,研究了放牧对张家界索溪峪景区土壤酶活性及微生物作用强度的影响。结果表明,从土壤酶活性、氨化作用强度与微生物活度来看,均以背景区土壤最强,缓冲区土壤次之,活动区土壤最小,而硝化作用强度的变化则正相反。放牧显著影响了0～5cm土壤的酶活性及微生物作用强度;在5～15cm土壤和15～25cm土壤层中,背景区和缓冲区的酶活性和微生物作用强度差异不显著,而与活动区的差异较显著。与有机质分解相关的微生物氨化作用强度、纤维素酶活性、木聚糖酶活性和蛋白酶活性的降低,主要是由于土壤有机质的投入减少而遭到减弱的,而硝化作用强度则主要与踩踏引起的土壤板结造成亚硝酸盐的积累有关,踩踏严重则硝化作用强度大。不同土壤层的微生物作用强度及酶活性强弱是0～5cm>5～15cm>15～25cm。放牧影响了景区内土壤微生物作用强度及酶活性,旅游活动破坏了生态系统抵御外界干扰的能力。

Ecological environment was destroyed by all kinds of recreation activities, such as animal-feeding and people＇s touching. In order to study the effect of visitors＂ activities on biological properties in soil and provide useful suggestion for ecological recreation, the research on microbial activities and enzyme activity in soil from Zhangjiajie National Forest Park was conducted. The soil enzyme activities were the highest in control zone, followed by those in buffer zone, and those in active zone were the lowest. The ammonification activities and microbial activities in soil were： the control zone〉buffer zone〉active zone, while, the nitrification activities in soil were the active zone〉buffer zone〉 control zone. The microbial activities and enzyme activities in 0-5 cm soil were markedly affected by recreational activities, while, they were not affected prominently in 5-15 cm and 15-25 cm layer soil from control zone and buffer zone, but significantly differed from those in active zone. The ammonification activities, including cellulase, xylanase and protease, which were associated with organic matter decomposing, were mainly affected by the quantities of organ matter. The nitificatlon activities were mainly affected by soil physical and chemical properties, which could improve the nitrite content. The microbial activities and enzyme activities in soil were： 0-5 cm〉5-15 cm〉15-25 cm. All these results showed that the microbial and enzyme activities in soil from Zhangjiajie National Forest Park were destroyed, and it＂ s necessary to make measures to protect Zhangjiajie National Forest Park from being destroyed.