云冷杉林土壤酶活性与植物多样性

Soil Enzyme Activities and Plant Diversity of Undergrowth in Spruce-fir Forest

以小兴安岭谷地云冷杉林为研究区,对不同生长状况云冷杉林地土壤酶活性与林下植物多样性进行了分析。结果表明:云冷杉林木死亡率增加,其林下植物多样性指数亦呈增加趋势。不同土层的土壤酶活性对云冷杉死亡程度响应不同,0～15cm土壤酶活性变化最为显著。随土层深度的增加,酶活性减小,且对云冷杉的死亡响应程度减弱。5种土壤酶活性对云冷杉死亡程度响应表现不一,脲酶和过氧化氢酶活性随死亡程度的加大对云冷杉死亡率响应较大,而转化酶、磷酸酶及多酚氧化酶活性随云冷杉死亡程度的增加下降幅度较小。林下植物Shannon-Wiener指数和Pielou指数与土壤多酚氧化酶活性的相关性最强,其次是过氧化氢酶。

The effects of different growth conditions on soil enzyme activity and plant diversity of spruce-fir forest were studied taking the low-lying land in Lesser Xing＇ an Mountains as the study area. Results showed that the diversity indices of the undergrowth increased with mortality rate of spruce and fir increasing. Activities of five kinds of soil enzymes varied with different soil layers, and the activities of soil enzymes in the top layer （0 - 15 cm） enhanced more distinctly compared with those in other layers. Also, the enzyme activities decreased with increasing soil depths in spruce-fir forest and their responses to death level of spruce and fir weakened gradually, exhibiting that urease and catalase activities highly responded to different death levels of spruce and fir, while invertase, alkaline phosphatase and polyphenol oxidase showed slight responses. Correlation analysis indicated that polyphenol oxidase activity was highly related to Shannon-Wiener index and Pielou index, and then followed by catalase.