Abstract：Soil enzymes activities were compared on different soil depth in Picea and Abies forest with different growth conditions.We studied the relation between different soil enzymes activities,and the different Picea and Abies forest in relation to soil nutrient and plant diversity.The results showed that the five soil enzymes activity varied decrease with increasing soil depth.And the soil enzymes in the top layer(0-15 cm) were enhanced distinctly compared with in the layers middle(15-35 cm) and subsoil(35-55 cm).Also,the five enzymes in the topsoil(0-15 cm) were affected differently by different level of deaths of Picea and Abies forest,showing that soil urease and catalase were highest response to different level of deaths of Picea and Abies forest,while invertase and phosphatase and polyphenol oxidase were response to slight.The response of soil organic matter to the death of Picea and Abies forest were most apparent.There were significant correlations between soil organic matter of contrast sample plot and intense death sample plot and super intense death sample plot(P<0.01).It was concluded that increasing the mortality of Picea and Abies forest was benefit to the development of diversity indices of the undergrowth,diversity of the undergrowth in shrub layer increased with increasing the death degree of Picea and Abies forest, but diversity of the undergrowth in herbaceous layer was initially increased then decreased.Correlation studies have shown that the most relevant exists among undergrownth plants Shannon-Wiener index and Pielou index and the soil polyphenol oxidase activity,followed by catalase.
2009, Vol. 7 
