The Study On The Ecological Response Of Phragmites Communis Under The Water Salt Gradient In Qingtu Lake

Compared with single factor to stress, drought, soil salinization double adversity influence on desert vegetation growth state is more serious.The same plant under the condition of different moisture, salt also show different ecological response.This research through to the minqin tengger desert green lake area soil under different water and salt gradient reed(Phragmites communis) determination of various growth character indexes, including sand moisture gradient, the comprehensive analysis on reed growth traits, sand reed salt gradient, the growth characters and comprehensive analysis, the physiological response of water and salt under dual stress sand reed, etc.To guide the rational using reed lake area in minqin county green soil resources, the improvement of desert ecological environment, wetland restoration and reconstruction of vegetation to provide scientific basis.Main conclusion: under different water and salt gradient, green lake area of sandy soil reed on photosynthesis, transpiration changes to the conditions of water and salt content of the response, reflect the different way of adaptation.Reed main photosynthesis and photosynthetic effective radiation, the influence of temperature and relative humidity of atmosphere, and the reed under salt stress, will be improved through photosynthesis to meet adversity.From different habitats in sand reed response, light intensity and CO2 concentration of high salinity, reed, keep to the weak light have higher utilization ability and strong photosynthetic capacity, but high salt also affect reed’s ability to use CO2 is low;Moisture content is low, reduces the reed’s ability to use weak light, but the reeds on the use of CO2 is wider.Reed leaf chlorophyll content, catalase activity mainly affected by water and salt together, soluble sugar content is mainly affected by the moisture, protein content, proline content and mda content was mainly affected by salt.Reeds green lake area of sandy soil salinity resistance is very strong, the influence of salt stress on the growth is very small, green lake area of sandy soil reed drought-resistant ability, growth is mainly influenced by water stress.And the government a year to the green lake area soil water in great quantities, caused the phenomenon of secondary salinization, looks like the sand reed in the case of water condition good, can effectively improve the phenomenon of secondary salinization.Groups of reed leaf area islarge, distribution, root water absorption ability is extremely strong, can keep out sunshine in the desert, provide effective shade, favorable sand m, l, sand plants.Reeds green lake area of sandy soil also have resistance to lodging, straight, plant height, stem thick, ye etc, camouflage effect of sunlight can effectively improve the soil water content under the strain, can be used as a desert wetland vegetation restoration, the species group at the forefront of the building.