莫莫格湿地芦苇对水盐变化的生理生态响应

Abstract

Understanding the eco-physiological response characteristics of Phragmites australis to water-salt condition is the key of determining the threshold of wetland ecological water requirement,in order to supply a feasible method for calculating the wetland ecological water requirement and scientific base for wetland restoration.By field investigation of Phragmites australis in Momoge wetland,we analyzed the relationship between eco-physiological characteristics of Phragmites australis and water-salt gradient with method of redundancy analysis(RDA) by using CANOCO software in Version 4.5.The results showed that the combination of three environmental factors including water depth,Na+ and HCO-3,explained 54.7% of the variation of eco-physiological responses of Phragmites australis,suggesting that the three environmental factors led to great changes in eco-physiological responses of Phragmites australis.Water depth was the key environmental factor influencing the growth of Phragmites australis.There was a significant positive correlationship between water depth and the eco-physiological characteristics including plant height,biomass,chlorophyll content,maximum photosynthesis efficient(FV/FM) and maximum photosynthesis performance index(PIABS).There was no significant correlationship between Na+/HCO-3 and the characteristics of Phragmites australis.The results suggested that it is the key point in the process of wetland restoration in mild or moderate saline-alkaline wetland to consider the influence of water depth on the growth of Phragmites australis,and secondly consider the effect of Na+/HCO-3,and determining the ecological water depth and fulfilling the ecological water requirement.