毛苔草光合作用日变化及其与环境因子关系的研究-Ⅰ  

Study on Diurnal Variation of Photosynthesis and Environmental Factors in Carex lasiocarpa—Ⅰ

作　　者：栾金花[1] 吕宪国[1] 

机构地区：[1]中国科学院东北地理与农业生态研究所

出　　处：《吉林农业大学学报》2008年第3期241-245,256,共6页Journal of Jilin Agricultural University

基　　金：中国科学院知识创新工程项目(KZCX3-SW-NA-01);中国科学院东北振兴科技行动计划重点项目(DBZX-2-024)

摘　　要：取三江平原沼泽湿地毛苔草(Carex lasiocarpa)无性系种群进行桶栽模拟试验,研究光合作用日变化及其与环境因子之间的关系。结果表明:土壤含水量保持在30%的前提下,毛苔草净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)的日变化趋势均呈单峰曲线变化,峰值均出现在8:30,胞间CO2浓度(Ci)和大气CO2浓度(Ca)的日变化呈近"V"型。光合有效辐射(PAR)和气温(Ta)的日变化呈单峰曲线;空气相对湿度(RH)的日变化趋势为先大幅度下降,之后平缓升高,再下降。毛苔草Pn与Tr、Gs均呈极显著正相关关系,与Ca、RH均呈显著正相关关系,与PAR呈不显著的正相关关系,与Ta、Ci均呈不显著的负相关关系。环境因子对毛苔草净合速率直接作用由大到小排序为RH>PAR>Ca>Ta;Ca通过RH对Pn的间接作用大于Ca对Pn的直接作用;毛苔草Pn日变化从8:30就开始下降的原因,既有气孔限制(Ls)的贡献也有非气孔限制的作用。The diurnal variation of photosynthesis and their environmental factors of Carex lasiocarpa clonal population of Sanjiang Plain Wetland were studied by barrel seedling simulation experiment.The results showed that especially when the soil moisture content was 30%,the diurnal changes of net photosynthetic rate（Pn）,transpiration rate（Tr） and stomatal conductance（Gs） were single-apex curves and the peak value were all present at 8：30.The diurnal changes of intercellular CO2 concentration（Ci） and atmospheric CO2 concentration （Ca） were ＂V＂ styles.The diurnal changes of photosynthetically active radiation（PAR） and atmospheric temperature（Ta） were a single-apex curve.The change trend of atmospheric relative humidity（RH） decreased greatly at first and then increased slowly,and it decreased again at last.The Pn of C.lasiocarpa was positively correlated with the Tr,Gs,PAR,Ca and RH,negatively correlated with Ta,and insignificantly negatively correlated with the Ci.The direct effects of environment factors on Pn of C.lasiocarpa were ordered from larger to small as RH〉PAR〉Ca〉Ta.RH was the most important factor which has effect on Pn,and the indirect effect of Ca through RH on Pn was greater than the direct effect of Ca on Pn.The reasons of diurnal variation of Pn of C.lasiocarpa decrease from 8：30 can be attributed to the effects of the stomatal limitation as well as the nonstomatal limitation.

关 键 词：毛苔草 净光合速率 日变化 环境因子 

分 类 号：Q945.79[生物学—植物学]