浑善达克沙地植物光合特性及蒸腾特性分析-analysis of photosynthetic characteristics and transpiration characteristics of plants in hunshandake sandy land.docxVIP

Study on the Photosynthetic and Transpiration Characteristics of Plants in the Ortindag sandy Abstract This paper made a comparative study about the photosynthetic and transpiration characteristics,and other physiological and environmental factors of 5 species of herbs,7 species of shrubs and 2 species of trees in Ortindag Sandy.To provide the basis theoretical for selecting the adaptability of plant species in Otingdag Sandy Land.The results are as follows: There have 4 types diurnal variation curve of stomatal conductance:“single peak type”,the type of “V”,always decreased type and basically stable type. The maximum daily mean stomatal conductance of difference life form which were Chenopodium glaucum (herb), Salix microstachya (shrub)and Ulmus pumila (tree). Diurnal variation curve of different plants can be divided into 4 types: with obvious photosynthtic “midday depression”; photosynthtic “midday depression”is not obvious; Diurnal variation curve as a “single peak”curve;The value of net photosynthetic rate is higher in the morning,with the advent of noon,the temperature becomes higher and environment humidity becomes lower, the value of net photosynthetic rate declines significantly,and basically had no further recovery in the afternoon. The daily mean net photosynthetic rate of Stipa baicalensis, Chenopodium glaucum and Agropyron cristatum are higher than other herbs, wich of Salix gordejevii and Salix microstachya are higher than other shrubs, and The daily mean net photosynthetic rate of Malus baccata is higher than Ulmus pumila. The diurnal variation curve of transpiration rate of most plant is “double peak”type, The daily mean transpiration rate of Stipa baicalensis, Chenopodium glaucum and Agropyron cristatum are higher than other herbs, which of Salix gordejevii and Salix microstachya are higher than other shrubs, and The daily mean net photosynthetic rate of Ulmus pumila is higher than Malus baccata. The diurnal variation curve of water use efficie