岷江上游干旱河谷海拔梯度上四川黄栌叶片特征及其与环境因子的关系

Leaf characteristics and Their Relationship of Cotinus coggygria in Arid River Valley Located in the Upper Reaches of Minjiang River with Environmental Factors Depending on Its Altitude Gradients

研究了岷江上游干旱河谷海拔梯度上四川黄栌(Cotinus coggyg ria)叶片特征及变化特点,以及它们与环境变化的相互关系.测定指标有叶片形态结构(叶长、叶宽、叶面积和叶长/叶宽),表皮特征(气孔器密度和面积、孔径、表皮细胞密度和面积)以及生态学特征(生物量、比叶重、饱和含水量).结果表明,随着海拔升高叶长、叶宽、叶面积、生物量、饱和含水量以及表皮细胞面积呈增大趋势;而表皮细胞密度呈减小趋势;气孔器面积和比叶重在海拔1 950 m以下,随着海拔上升而增加,1 950 m的区域明显减小,气孔器密度的变化趋势与之相反;孔径和叶长/叶宽无明显变化.多元统计分析显示:叶面积、饱和含水量和气孔器面积主要与温和度有关,三者随着海拔升高和温和度降低呈增大趋势;随着水热综合因子的增加,气孔器密度减小而孔径和比叶重增大;随着年降水量的增加生物量和气孔器面积呈增大趋势,而表皮细胞密度减小;表皮细胞面积随着生物温度降低而增加.综合分析表明,岷江上游干旱河谷缺水和生长季节高温是影响叶片特征变化的主要因素.

The leaf characteristics and their relationship of Cotinus coggygria in arid river valley located in the upper reaches of Minjiang River with environments factor in terms of its altitude gradients were studied. The parameters measured in this study were parameters of leaf morphology （leaf length, area and width, and leaf length/leaf width）,epidermis parameters （stomatal density, area and diameter,epidermal cell density and area） and biological parameters （biomass,specific weight,and saturated water content）. The results showed that with increased elevation above sea level ,the length,width ,area ,biomass and saturated water content of the leaves tended to increase,and the epidermal cell density tended to decline; the stomatal area and leaf specific weight increased as the elevation above sea level went up to 1950 m,and remarkably declined as the elevation above sea level surpassed 1 950 meters,but the stomatal density tended to contrarily vary;the stomatal diameter and the leaf length/width ratio did not clearly varied. The multivariate statistical analysis revealed that the leaf area and saturated water content, and stomatal area mainly related to temperature and tended to increase with increased elevation and decreased temperature; with comprehensively increased water and warmth conditions,the stomatal densities decreased but the stomatal diameter and leaf specific weight increased;with increased annual rainfall,the biomass and stomatal area tended to increase ,but the epidermal cell density decreased ;the epidermal cell area increased with decreased biological temperature. On all accounts,water shortage and high temperature during the period of growth are main factors to cause the leaf characteristics to vary in the upper reaches of Minjiang River.