Study On The Spatial Variation Of Soil Chemical Properties In Typical Wetland

Wetland ecosystem is very sensitive. The unreasonable development and utilization, lead to the wetland area drastically reduced, loss of biodiversity, and ecological function degradation,which is serious harm to the stability of the wetland ecosystem and sustainable development. Protect, restore and rational utilization of the wetland is become the focus of scientists and government officials’ attention in recent years. This article takes wetland(international important wetland) soil of the national nature reserve of black-necked cranes in Dashanbao Town Yunnan Province as the research object. It selects the most representative two pieces of typical wetland which are Tiaodunhe reservoir Xiaohaiba and Dahaizi reservoir Dafazitang to set 2 piece of soil sample. Dafazitang sample contains 1 belt of vertical sample, 1 transverse strip and 1 to take. Xiaohaiba sample contains 1 belt of vertical sample and 2 to take.Along the strip, and every 10 m set of plant samples, set up soil samples. Xiaohaiba sample area has 32 sample, sample Dafazitang with 28 points. Through the analysis of the soil sample of 60 sampling points, it discusses the typical wetland soil chemical properties micro gradient space variation characteristics, and analyzes the influencing factors. The result showed as follows.1.In the study area, the typical wetland soil is acidic. Organic matter,exchangeable potassium, sodium, calcium, magnesium and cation exchange capacity content of soil are very rich. Total nitrogen, total phosphorus, hydrolyze nitrogen, available phosphorus content is very low. Total potassium content is very low.Rapidly-available potassium content is low. Full amount of copper, zinc, iron content is significantly higher than the national average. Total amount of Mn content is slightly lower than the background value in yunnan province. Effective copper, iron,manganese, boron content is high. Effective zinc, sulfur content is low.2.Look from the soil profile, from top to bottom, organic matter, exchangeable potassium, available potassium, total amount of zinc, total amount of iron, effective sulfur content are decrease. pH value, effective, iron, manganese, boron content ishigher. Exchangeable sodium, calcium, magnesium and cation exchange capacity,total amount of nitrogen, phosphorus, potassium, available nitrogen and phosphorus,total amount of copper and manganese, copper and zinc content is significant difference in vertical direction.3.Typical wetland soil total phosphorus with the decreasing water levels in the study area shows the tendency of decrease,and the total potassium content gradually increase. pH value, exchangeable calcium, exchangeable magnesium content decrease with the decreasing water levels in Xiaohaiba sample area, and don’t present the corresponding water level change trend in Dafazitang sample area. Total amount of copper, zinc content increases with the decreasing water levels in Dafazitang sample area, and don’t present the corresponding water level change trend in Xiaohaiba sample area.Available phosphorus, effective boron content decreases with the decreasing water levels in Dafazitang sample area, and don’t present the corresponding water level change trend in Xiaohaiba sample area. Organic matter,exchangeable potassium and sodium, CEC, total amount of nitrogen hydrolyze nitrogen, rapidly-available potassium, total amount of iron and manganese, copper,zinc, iron, manganese, sulfur don’t present corresponding change trend with the decreasing water level.4.Soil chemical properties are affected by parent material, ground water, river,vegetation, cutting the influence of peat and farming reclamation planting, and correlation between chemical elements will also affect the soil chemical properties.The content in the horizontal and vertical direction volatile largerly.