The Effect Of Cutting On The Growth Status Of Common Reed And Soil Enzyme Activity In Riparian Wetland

As a kind of aquatic-terrestrial ecotone, riparian wetland plays an important role in water conservation, defending flood and drought, maintaining biodiversity and ecological balance, easing non-point pollution and so on. In recent years, because of the degradation of riparian wetland, a series of riparian wetland restoration and reconstruction projects have been launched all over the world, while most of these projects attach importance to restoration but neglect management, then it's hard to make full use of the comprehensive benefits of wetland restoration project. This thesis chooses reed community of artificial restoration in Suzhou Taihu National Tourism Vacation Zone as the study object. The growth status of common reed, soil nutrients, microbes and enzyme activities were analyzed in order to provide basis for the management of wetland restoration projects. The main results were as follows:1. The density and stem height of reed community under two treatments was significant differences, the stem height of cutting model was 3.27±0.12m, while it was 1.19 times higher than naturally reserved one. The density of reed was 43±2 trunk·m-2, it dropped almost a quarter. There was no remarkable impact on the biomass and stem diameter under two treatments.2. There was no significant effect on soil nutrients except available phosphorus under two treatments, compared with the uncutting treatment, the available phosphorus decreased 25.73%, 21.70% and 30.23% in the same soil lay in cutting treatment. The seasonal changes of soil nutrients under two controls showed that the content in spring and autumn was higher than in summer and winter.3. The number of bacteria, fungi, actinomycetes decreased with the increased depth of the soil layer under two treatments, there was no significant differences between the same soil layer under two treatments. The seasonal changes of bacteria and actinomycetes quantity were autumn>spring>winter>summer, while fungi quantity was spring>autumn>winter>summer in two controls.4. There was significant effect on soil invertase activity and alkaline phosphates under two treatments, soil invertase activity in surface and subsurface was decreased 36.05%and 19.75% in cutting treatment and alkaline phosphates of surface decreased 30.85%, compared with uncutting treatment, while there was no significant effect on urease and catalase activity. The seasonal changes of surface soil (0～10cm) enzyme activities under two control showed that the soil enzyme activities were higher in spring and autumn, lower in winter and summer.5. The correlation analysis showed that:there was a very positive correlation between soil nutrients, microbes and enzyme activities. The path analysis showed that the main cause of deceasing enzyme activities was deceased of soil nutrient content by reed cutting.