Photosynthetic Physiology For Several Kinds Of Evergreen Broad-leaved Plants In Jinyun Mountain

Jinyun Mountain is known as "the Little Three Gorges of Jialing River ", which is natural green barrier and an important water conservation district in Chongqing. Soil moisture conditions have great influence on plant photosynthetic rate, transpiration rate, water use efficiency and other physiological mechanisms, and adequate soil moisture can ensure the progress of the physiological processes of plants and organic matter accumulation smoothly. Chongqing is located in China southwest acid rain area of China, and the high frequency of acid rain will damage plant growth and even lead to their apoptosis.In this paper, the portable photosynthesis system LI-6400was adopted to reserch the photosynthetic physiological characteristics of physiological processes of three kinds of evergreen broad-leaved species of Jinyun in diffrent habitats and the adaptability of each species on the local ecological environment is presented which provide a basis for water conservation, vegetation construction,and cultivation of the fine trees in Jinyun Mountain. The main conclusions are as follows:The results in natural environment indicated that, In the respect of the maximal net photosynthetic rate, Symplocos setchuensis Brand> Neolitsea auratavar. Glauca>ordonia acuminata Chang,Symplocos setchuensis Brand’s transpiration rate was the highest of the three kind of broadleaf woody plants, and the sequence of water use efficiency was in order of Neolitsea auratavar. Glauca> ordonia acuminata> Symplocos setchuensis Brand.Under Soil water stress conditions, Neolitsea auratavar died first,then the Symplocos setchuensis Brand and thelast one is the Ordonia acuminata Chang In the process of natural drought. The three kind of broadleaf woody plants can keep on a high level in net photosynthetic rate when the soil moisture were between19%-46%.Under mild drought stress, Symplocos setchuensis Brand’s net photosynthetic rate was the highest, and then the Symplocos setchuensis Brand, ordonia acuminata Chang was the lowest. The order of Pn under medium drought stress is ordonia acuminata Chang> Neolitsea auratavar. Glauca> Symplocos setchuensis Brand, and Symplocos setchuensis Brand> Neolitsea auratavar. Glauca>ordonia acuminata Chang under Severe drought stress.Under acid rain stress environmental conditions, pH=2.0, pH=2.5simulated acid rain stress resulted photosynthetic rate of the ordonia acuminata Chang, Neolitsea auratavar. Glauca, and Symplocos setchuensis Brand showing a "convex" transformation trend; pH=3.5acid rain stress caused the Solanum Neolitsea net photosynthetic rate decreased slightly, while ordonia acuminata Chang and Neolitsea auratavar. Glauca’s net photosynthetic rate were promoted. The acid rain influence of Symplocos setchuensis Brand is smaller than ordonia acuminata Chang and Neolitsea auratavar. Glauca...