沙柳光合作用和蒸腾作用日动态变化的初步研究  

Primary studies on the daily dynamic changes of photo-synthesis and transpiration of Salix psammophila

作　　者：黄振英[1] 董学军[1] 蒋高明[1] 袁文平[1] 

机构地区：[1]中国科学院植物研究所植被数量生态学开放研究实验室,北京100093

出　　处：《西北植物学报》2002年第4期817-823,共7页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金资助项目 ( 3989336 0 ) ;国家自然科学基金 ( 30 0 0 0 0 2 1) ;中国科学院知识创新工程项目"浑善达克沙地与京北农牧区交错区环境综合治理试验示范研究"资助

摘　　要：沙柳是毛乌素沙地流动沙丘和固定沙丘上广泛分布的重要固沙植物。叶片的光合速率呈现出不规则的日动态变化 ,在 1 0 :0 0～ 1 1 :0 0及 1 4 :0 0出现光合午休现象。蒸腾速率呈现出单峰型的日动态变化 ,蒸腾在午后 1 5:0 0达到最大。水分利用效率在早晨 9:0 0后保持在 2～ 2 .5μmol CO2 · mmol-1 H2 O左右。叶片水分亏缺也表现出规律性的变化。从早晨开始 ,叶片水分亏缺逐渐增大 ,在 1 8:0 0达到最大值。比较生长季节的不同时期环境因子的变化情况表明 ,春末的光照强度和气温比夏末高 ,但土壤水分含量则相反。沙柳在春末的光合速率、蒸腾速率分别是夏末的 79%和 72 .4% ,表明水分亏缺是影响沙柳生长发育的主要限制因素。Salix psammophila is an important sand fixing plant inhibited in the moving or stable sand dunes of MuUs sand land.The daily dynamics changes of photosynthesis rate presents irregular curve,and the midday depression of photosynthesis appears at 10:00-11:00 and 14:00.The daily dynamics changes of transpiration rate presents one peak,and the maximum reached at 15:00.The volume of water use efficiency keeps at 2-2.5 μmol CO 2·mmol -1 H 2O after 9:00 in the morning.Water deficiency of leaves presents rhythmical changes,the volumes gradually increase from morning and reached the maximum at 18:00 in the afternoon.When comparing the changes of environmental factors of different stages in the growing season,light intensity and air temperature in the late spring are higher than late summer,but the soil moisture content are opposite.The photosynthesis rate and transpiration rate in the late spring are 79% and 72.4%,respectively to that in late summer,indicating water deficiency is the main limiting factor that influences the development of Salix psammophila .The differences of water use in different seasons is a plastic adaptation for the environment stress.

关 键 词：沙柳 光合作用 蒸腾作用 日动态变化 

分 类 号：Q945.11[生物学—植物学] S793[农业科学—林木遗传育种]