| 摘要: |
| [目的]研究黄土丘陵沟壑区沙棘叶片的光合速率和气孔导度特性及其耦合关系,建立干旱条件下沙棘叶片气孔导度模型.[方法]以Li-6400便携式光合仪测定的气体交换观测数据为基础,分析了沙棘叶片的光合速率(Pn)、胞间CO2浓度(Ci)和气孔导度(Gs)的相关性,用Ball-berry和非直角双曲线光合模型描述了光合速率与气孔导度间的关系.[结果]沙棘叶片Pn与Gs日变化相对应且均呈现同步不对称"双峰"波动,具有典型"午休"现象,首峰出现在上午9:00左右,次峰峰值小于首峰,出现在下午15:00以后;沙棘叶片Pn与Gs呈正偏相关关系,而与Ci呈负偏相关关系,且不同月份Ci与Pn的偏相关系数均高于Gs与Pn,但Gs与Ci的简单相关并不稳定,8月份未达显著水平;Pn与Gs、光合有效辐射(PAR)的简单相关分析表明,Pn与Gs、PAR间均呈极显著正相关关系(R2=0.895 4,R2=0.990 2).[结论]沙棘叶片衰老期间非气孔因素是光合作用的主要限制因子.联合Ball-berry气孔导度模型和非直角双曲线光合模型建立的黄土丘陵沟壑区沙棘叶片气孔导度对环境因子的响应模型,具有一定的适用性. |
| 关键词: 沙棘 气孔导度 光合速率 环境因子 气孔模拟 |
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| 基金项目:国家科技支撑计划，国际泥沙研究培训中心重大项目 |
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| Characteristics and quantitative simulation of photosynthetic rate and stomatal conductance on Hippophae rhamnoides L. in loess Hilly Region |
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| Abstract: |
| 【Objective】 The dynamic characteristics and the relationship between stomatal conductance and photosynthetic rate were studied to develop a leaf stomatal conductance model for Hippophae rhamnoide L.in Loess Hilly Region.【Method】Based on field measurements of stomatal conductance and photosynthesis data of Li-6400 portable photosynthesis system,the relationship between Pn,Gs and Ci was analyzed.And the Ball-Berry model and a nonrectangular hyperbolic photosynthesis model were employed to simulate the relationship of stomatal conductance of Hippophae rhamnoide L.【Result】 The results showed that the diurnal variation of Pn and Gs was a smooth two-peak curve on sunny day,and Gs increased rapidly around 9:00 A.M.,followed by marked decrease until about 15:00 P.M.The Pn associated with Gs,exhibited and sustained oscillations hours after sunrise,and reached a peak at about the diurnal course simultaneously.Pn had positively significant partial correlation with Gs,but negatively significant partial correlation with Ci.The partial correlation coefficients between Pn and Ci were higher than those between Pn and Gs in different months,but Ci didn’t sustain significant correlation with Gs.The relationship between Ci and Gs wasn't significant in August.It also showed that there was a linear relationship between Gs and Pn,and a nonrectangular hyperbolic relationship between Pn and PAR (R2=0.895 4,R2= 0.990 2).【Conclusion】 The result suggests that the non-stomatal factor was the main limiting element in the leaf senescence periods;thus,a leaf Stomatal Conductance model was constructed by coupling a Ball-Berry model and a nonrectangular hyperbolic photosynthesis model for Hippophae rhamnoi de L.in Loess Hilly Region. |
| Key words: Hippophae rhamnoides L. stomatal conductance photosynthetic rate environmental factor stomatal conductance simulation |
