Sap Flow of Abies georgei var. smithii and Its Relationship with the Environment Factors in the Tibetan Subalpine Region, China  

作　　者：GUO Qi-qiang ZHANG Wen-hui 

机构地区：[1]Forestry College, Northwest A&F University [2]Tibet Agricultural and Animal Husbandry College [3]National Key Station for Field Scientific Observation & Experiment

出　　处：《Journal of Mountain Science》2015年第6期1373-1382,共10页山地科学学报（英文）

基　　金：supported by the Tibetan Natural Scientific Foundation of China (13-28);Tibetan Linzhi National Forest Ecological Research Station (2012-LYPT-DW-016);Promotion Plan of Plateau Basic Ecological Academic Team Ability;supported by CFERN&GENE Award funds on ecological paper

摘　　要：Abies georgei var. smithii is a dominant species playing an important role in protecting biodiversity and sustaining the forestry ecosystems in Southeastern Tibetan Plateau. Stem sap flows of five different diameters at the breast height(DBH) A. georgei var. smithii samples were monitored continuously with the thermal dissipation probe for the entire growing period in order to understand the water transportation mechanism and the effects of environmental factors on its transpiration and growth. Relative environment factors, temperature and humidity of air, photosynthetically active radiation, rainfall, and wind speed, soil moisture, etc. were measured by the automatic weather stations. Diurnal and seasonal variations in sap flow rate with the different stem diameters and their correlations with meteorological factors were analyzed. The diurnal change in sap flow velocity showed a single-peak curve at the daily time scale, whereas a lower sap flow velocity can be observed in the largest DBH sample tree at night. The maximum average velocity was observed in August, whereas the minimum velocity was observed in January, and a large amount of water evaporated in summer owing to the higher sap flow velocity. In addition, sap flow velocity was closely related to changes in the micrometeorological factors, with average sap flow velocity showing significant linear correlations with air temperature, photosynthetically active radiation, rainfall, and vapor pressure deficit of air and soil moisture. Therefore, some measures, improving the light and temperature conditions, should be taken for protecting A. georgei var. smithii population in the Tibetan Plateau.

关 键 词：Tibet Subalpine region Thermal dissipation probe Abies georgei var.smithii Sap flow velocity Environment factor 

分 类 号：S791.14[农业科学—林木遗传育种]