摘要
采用美国产ＬＩ－６０００便携式光合分析系统对库布齐沙地植被建群种油蒿等主要沙生植物的光合作用及环境因子进行研究。结果表明，油蒿（Ａｒｔｅｍｉｓｉａｏｒｄｏｓｉｃａ）等主要沙生植物光合作用都有午休现象，但光合速率差异很大。油蒿表现最大光合作用的时间在８月份，较地上生物量的高峰期提前１个月左右。有效光辐射是影响油蒿光合作用的主导因子。油蒿光合速率（ＰＨ）和主要环境因子——气温（ＡＴ）、有效光辐射（ＰＡＲ）和大气相对湿度（ＲＨ）之间的多元线性回归方程为：ＰＨ＝０．２９５＋０．０００９９４ＰＡＲ＋０．００１７４ＲＨ－０．００１１ＡＴ。
The photosynthesis of Artemisia ordosica as a dominant species and other principal species, and their relations to environmental factors have been studied by us using portable LI 6000 photosynthesis measure system in Hobq desert form June to September in 1996. Results show that the photosynthesis of Artemisia ordosica and others have similar diurnal variation and trend which have bi peak and noon depression. The rate of photosynthesis ( PH ) of A. ordosica increases as environmental factors such as active radiation and air temperature increase, but relative air humidity factor is not including. The first peak of photosynthesis of A. ordosica emerges during 10￣12 a.m., and its second peak appears during 14￣16 p. m.. There is a depression between two peaks at the photosynthesis curve of A. ordosica , which followed the second peak PH of A. ordosica decreases gradually. A. ordosica and other species similarily acclimatized to environmental conditions, but there are still some differences in different species. For example, different plants PH noon depressions are dramatically changeable, meanwhile peaks emerging time vary in spite of their lying same period. Noon depression maybe relate to high active radiation, hight air temperature and low air humidity because these factors can result in stoma closing, and CO 2 exchange is also handicapped by these. PH of A. ordosica has obviously seasonal variation, it rises from April and reaches the highest in August, then declines gradually. The above ground biomass ( AGB ) of A. ordosica reaches the highest value in September and it is behind the PH peak (August). We consider that AGB represents the accumulation of photosynthesis, but PH is only instant value which indicates plants photosynthesis trait in measuring time. The photosynthesis is affected by lots of environmental factors, meantime the environmental factors influence each other. The importance of the factors are active radiation ( PAR )>relative humidity (RH )>air temperature (AT) by pathanalysis, and the multiple regression equation is PH=0 295+0 000994PAR+0 00174RH-0 0011AT (P=0 0000001).
出处
《中国沙漠》
CSCD
北大核心
1999年第3期276-279,共4页
Journal of Desert Research
基金
国家自然科学基金
关键词
库布齐沙地
油蒿
光合作用
环境因子
沙生植物
Hobq sandy land
Artemisia ordosica
photosynthesis
environmental factors
