自然条件下盐城海滨湿地土壤水分/盐度空间分异及其与植被关系研究

Spatial Variation of Soil Moisture/Salinity and the Relationship with Vegetation Under Natural Conditions in Yancheng Coastal Wetland

以盐城国家级自然保护区核心区为案例,根据2011年4～5月对海滨湿地土壤采样分析结果,结合2011年ETM+遥感影像,运用典范对应分析(CCA)、线性回归模拟和地统计学方法,探索自然条件下盐城海滨湿地土壤水分和盐度的空间分异特征及其与植被类型的关系.结果表明:①土壤水分平均值在36.820%～46.333%之间;土壤盐度平均值在0.347%～1.328%之间,具体表现为米草滩>光滩>碱蓬滩>芦苇滩.②土壤水分和盐度的空间变异具有一致性,东西海陆方向上的变异大于南北海岸延伸方向上的变异.土壤水分和盐度最高值出现在西南部米草滩;最低值出现在芦苇滩内.将土壤水分和盐度从低到高分成Ⅰ到Ⅴ级,其中Ⅳ级比重最高,分别占36.156%和28.531%.③不同植被类型的土壤水分和盐度的组合呈现高盐度高水分到低盐度低水分的"双高到双低"组合特征.具体表现为:芦苇滩土壤水分<40.116%,盐度<0.676%;碱蓬滩土壤水分为38.162%～46.403%,盐度为0.471%～1.295%;米草滩土壤水分>43.214%,盐度>1.090%;光滩的土壤水分>43.214%,盐度>0.677%.

Taking the core part of Yancheng national nature reserve as the study area,according to soil sampling analysis of coastal wetlands in April and May 2011and the 2011 ETM＋remote sensing image,the spatial difference characteristic of coastal wetlands soil moisture and salinity,and the relationship with vegetation under natural conditions,were investigated with the model of correspondence analysis（CCA）,linear regression simulation and geo-statistical method.The results showed： Firstly,the average level of the soil moisture was fluctuating between 36.820% and 46.333%,and the soil salinity was between 0.347% and 1.328%,in a more detailed sense,the Spartina swamp was the highest,followed by the mudflats swamp,the Suaeda salsa swamp,and the Reed marsh.Secondly,the spatial variation of soil moisture was consistent with that of the salinity,and the degree of variation in the east-west direction was greater than that in the north-south.The maximum soil moisture and salinity were found in the southwest Spartina swamp.The minimum was in the Reed swamp.The soil moisture and salinity were divided into 5 levels,fromⅠtoⅤ.Level Ⅳoccupied the highest proportion,which were 36.156% and 28.531%,respectively.Finally,different landscape types with the combination of soil moisture and salinity showed a common feature that the moisture and salinity were from both high to low.The soil moisture value of Reed marshes was lower than 40.116% and the salinity value was lower than 0.676%.The soil moisture value of Suaeda salsa marshes was between 38.162% and 46.403% and the salinity value was between 0.417% and 1.295%.The soil moisture value of Spartina swamp was higher than 43.214% and the salinity was higher than 1.090%.The soil moisture value of beach was higher than 43.214% and the salinity was higher than 0.677%.