崇明东滩湿地土壤生物活性差异性及环境效应分析

The Analysis of Bioactivity and Environmental Effect of Different Types of Wetland Soil in Chongming Dongtan

为了解不同类型滩涂湿地土壤生物活性和生态环境效应,以及不同农业利用模式对围垦滩涂土壤肥力和生物活性的影响,在崇明东滩选取堤内为不同农业利用模式、堤外为不同类型湿地的3个实验样区。分别采取湿地土壤样品,测定土壤中微生物量、有机质含量、土壤酶活性,分析不同类型土壤的生物活性和生态环境效应。结果表明,3类堤外湿地土壤中,沙质型的芦苇湿地土壤(A区)有利于微生物的呼吸、代谢与繁殖,具有较高的有机污染物净化能力,而粘土型的芦苇/米草混合湿地土壤通过微生物呼吸作用降解有机物的能力较弱,但是具有较高的碳积累能力以及氮磷等农业污染物的转化、吸收能力。堤内通过框围养鱼、水稻耕种以及果蔬种植等程序式农业利用模式,围垦滩涂土壤肥力和生物活性可以得到逐步提高,同时在上述各农业利用阶段可分别获得经济效益,是一种值得提倡的湿地利用方式。

To attain the bioactivity and environmental effect of different types of wetland soil and the effect of agricultural utilization mode on the fertilization and bioactivity of the inning land, three different types of wetlands in Chongming Dongtan were chosen as experimental districts. The bioactivities and environmental effects of the three types of wetland soil were analyzed by measuring the biomass, organic matter and soil enzyme activity. The results showed that the biomass of area A was 5 times more than that of ether two areas. The catalase of area A was about 0.21 mL 0. 1 mol. L^-1 KMnO4·g^-1 while area C＇s catalase is only about 0.04 mL 0.1mol· L^-1 KMnO4·g^-1 And the invertase of area A was stronger than that of area B and area C. However, the urease and alkaline phosphatase of area B and area C was much higher than area A. Consequently, it was propitious to the breath, metabolism and growth of microbes in the sandy wetland soil with Bulrush （area A）, Thus the degradation ability of the sandy soil with Bulrush to organic pollutant may be stronger than the clay soils which was mixed with Bulrush and Spartina alterniflora （area B and C）. However, the cumulation ability of carbons of area B and C＇s soil was better than area A, In addition, the transformation ability of nitrogen and phosphorus in clay soils mixed with Bulrush and Spartina alternifiora（area B and C） was better than area A. The experimental results also showed that the fertilization and bioactivity of the inning land in the inner levee could be impro：＇ed by the sequenced agricultural utilization mode： breeding fish→planting paddies→planting vegetables. The sequenced agricultural utilization mode can bring to great benefit during different utilization stage, and the fertilization of the inning lands can be improved at the same time, Therefore, this mode is an effective way to make use of the inning lands.