Warm Temperate Dominant Shrubs Transpiration Rhythm Experiments

Water is the most important factor to life-form, and it is also the key factor which can influence the ecosystem. Thinking of the status of lack of water resources in Shandong province, the regulation of water requirement of plants should be researched, and the plants which need less water to grow should be developed. In that way, the problem of water lacking in the process of vegetation restoration can be resolved.The mensuration and calculation of transpiration and evaporation of plants are now the keystones in plant physiology. However, the general techniques can not differentiate between transpiration and evaporation. Because sap flow is the ascending process caused by transpiration in plants, the value of transpiration can be approximatively considered as sap flow value. At present, HPVR and SHB are widely used to measure sap flow.In this paper, three species of shrubs had been chosen for research, Vitex negundo L., Zizipbus jujuba Mill., Lespedeza bicolor Turcz.. And Berberls thunbergii DC. was chosen as the referencing plant, which is a common species for virescence. From Jul to Sep, the sap flow of plants and five environmental factors were measured in the fast growing season. Then, conventional statistical methods were used for data analysis.The result showed, in the whole fast growing season, the sap flow change of the four kinds of plants represented difference between species, the size and the range of cycle displayed discordantly. Vitex negundo L. and Lespedeza bicolor Turcz. displayed one total cycle in the whole observation period, Zizipbus jujuba Mill, displayed two cycles, while Berberls thunbergii DC. didn't display evident...