桉树林地土壤酶分布特点及其活性变化研究

Distribution of the Soil Enzyme and Its Activities in Eucalyptus Plantations

对资兴市桉树人工林地土壤酶的分布及其活性的研究表明 :土壤酶的分布呈现出一定的规律性 ,即土壤转化酶、过氧化氢酶、脲酶和蛋白酶等 4种酶随土层深度的增加酶活性依次减弱 ,以 0～ 2 0 cm土层的酶活性最大 ;在同一层次土壤中 ,土壤酶活性一般下坡 >中坡 >上坡 ,但蛋白酶的变化不明显 .桉树人工林地土壤酶活性与对照杉木林地相比 ,对照区酶活性明显优于桉树林地 .立地条件好、栽植时间短的桉树林地 ,土壤酶活性高 .桉树林分蓄积量和平均木生物量及林分生物量与蛋白酶和转化酶存在一定的负相关 。

The results of the study on the distribution and its actiaities in Encalyptus plantations in ZiXing City showed that the distribution of soil enzyme presents regular patterns(in the 0~20cm, 20~40cm and 40~60cm soil layer)——the enzymatic activities of urease, invertase, proteinase and peroxidase rapidly declined with the increase of soil depth, and the largest sail enzymatic activities occurred in 0～20 cm. In the same soil layer, the tendency of changing patterns of soil enzymatic activities was lower slope> middle slope>upper slope but the changing patterns of proteinase was not so obvious to be seen.Compared with Chinese fir plantations, the soil enzymatic activities of Eucalyptus plantations were much lower. The soil enzymatic activities of Eucalyptus plantations were higher in the superior site conditions and junior stands. The stands volume and stands or single tree biomass were negatively correlated with proteinase and invertase, which showed that proteinase and invertase of the soil enzymes depressed accumulation of soil nutrient.