Effects Of Groundwater Depth And Salinity On The Photosynthetic Physiological Process Of Chinese Tamarix

The Yellow River delta is a new land which is formed by many years erosion and accumulation. It has important ecological function and scientific research value. Due to human and natural factors, the forest vegetation is sparse, the forest growth is slow, the vegetation degradation is serious and the soil and water loss is increased,in a word the ecosystem is fragile. It is urgent to restore and rebuild the vegetation in this area. Chinese Tamarisk is an major species in the region, and how to carry on the restoration and reconstruction of Chinese Tamarix is very important. According to many years of research,the distribution of vegetation and community succession in the Yellow River delta is greatly influenced by the groundwater level and soil salinity and the salinity of soil is closely related to the mineralization degree of groundwater. Limited by groundwater level and mineralization degree, the available water resources are sorely lacking.And thus, to put the depth and mineralization degree of groundwater as the main source of water and salt, study the effects of groundwater depth and mineralization degree to the Chinese Tamarix, photosynthetic physiological and ecological process has an important significance to the restoration and reconstruction of Chinese Tamarix.This article through the simulation of groundwater level and mineralization degree of coastal saline alkali land in the Yellow River Delta,make the relationship between groundwater level and salinity conditions, soil water content and salt content to be determined and analyzed,also,make The groundwater level and salinity conditions suitable for the growth of Tamarix chinensis to be clear. In order to provide theoretical and technical reference for the construction of coastal saline alkali land in the Yellow River Delta. The main research results are as follows:(1)The groundwater level and salinity can affect soil water and salt, and then make a inffluence on Tamarix chinensis photosynthetic characteristics and SAP flow. When the groundwater level is from 0m to 1.2m, the main source of water and salt in the surface soil isgroundwater.And when the groundwater level is from 1.2m to 1.8m, the main source of water and salt in the surface soil is meteoric water or condensed water.(2)Tamarix seedlings have strong adaptability to drought and salt stress, moderately improve the groundwater level and mineralization of Tamarix chinensis can significantly enhance the photosynthetic capacity and water consumption and reduce the water use efficiency. Within the scope of this study, Pn of Tamarix decreased mainly by non stomatal limitation. The groundwater level is 1.2m, the highest photosynthetic efficiency of Tamarix chinensis and salt water treatment is more conducive to the growth of Tamarix chinensis seedlings. Tamarix chinensis in the muddy coast of the underground salt water salinity has the best adaptability and The groundwater level suitable for its growth is 0.67-1.65 m.This conclusion for the growth and survival of Tamarix chinensis in the Yellow River delta muddy coast has a important significance...