CAJ | 학술논문

光合作用是自然生态系统能量流动的基础，植物光合特性决定了生态系统初级生产力的高低。植物不同生长阶段光合特性既对生态系统能量的输入有重要影响，也是种群更新发育的主要驱动因子。在森林生态系统中，优势种的光合生理生态特性影响着整个生态系统的结构和功能。伏牛山自然保护区地处北亚热带到南暖温带交错地带，保存着完整的森林生态系统类型。栓皮栎（ Quercus variabilis）作为低海拔区域的主要优势种，更新良好，分层明显。采用Li－6400光合仪和荧光仪等对不同生长阶段栓皮栎植株（乔木、灌木与幼苗）进行野外光合测定，并分别测定其叶绿素含量。结果表明：（1）与栓皮栎乔木和灌木相比，栓皮栎幼苗的表观量子效率最高，叶片叶绿素含量最高，暗呼吸速率最低，光补偿点最低；（2）与栓皮栎灌木和幼苗相比，栓皮栎乔木对高光的适应能力最强，叶绿素含量最低，栓皮栎的“光合午休”现象并不存在，各层净光合速率日变化主要受光强控制；（3）栓皮栎乔木的PSⅡ最大光化学量子效率最高，幼苗最低；（4）栓皮栎乔木、灌木和幼苗的气孔导度和蒸腾速率均表现为上午高于下午，栓皮栎灌木和幼苗的水分利用效率表现为上午高于下午，而栓皮栎乔木水分利用效率则表现为下午高于上午。不同生长阶段栓皮栎植株光合生理生态特性的这种差异化使它们能适应不同的环境。栓皮栎各层长势良好，更新力强，具有正向演替的内在驱动力。
광합작용시자연생태계통능량류동적기출，식물광합특성결정료생태계통초급생산력적고저。식물불동생장계단광합특성기대생태계통능량적수입유중요영향，야시충군경신발육적주요구동인자。재삼림생태계통중，우세충적광합생리생태특성영향착정개생태계통적결구화공능。복우산자연보호구지처북아열대도남난온대교착지대，보존착완정적삼림생태계통류형。전피력（ Quercus variabilis）작위저해발구역적주요우세충，경신량호，분층명현。채용Li－6400광합의화형광의등대불동생장계단전피력식주（교목、관목여유묘）진행야외광합측정，병분별측정기협록소함량。결과표명：（1）여전피력교목화관목상비，전피력유묘적표관양자효솔최고，협편협록소함량최고，암호흡속솔최저，광보상점최저；（2）여전피력관목화유묘상비，전피력교목대고광적괄응능력최강，협록소함량최저，전피력적“광합오휴”현상병불존재，각층정광합속솔일변화주요수광강공제；（3）전피력교목적PSⅡ최대광화학양자효솔최고，유묘최저；（4）전피력교목、관목화유묘적기공도도화증등속솔균표현위상오고우하오，전피력관목화유묘적수분이용효솔표현위상오고우하오，이전피력교목수분이용효솔칙표현위하오고우상오。불동생장계단전피력식주광합생리생태특성적저충차이화사타문능괄응불동적배경。전피력각층장세량호，경신력강，구유정향연체적내재구동력。
Photosynthesis is the basis of energy flow in natural ecosystems and plants′photosynthesis characteristics deter?mine primary productivity of an ecosystem. Plant photosynthetic characteristics, though varying with different plant devel?opmental stages,are not only an important factor influencing energy input of the eco?system, but also a major driving factor of regeneration and development of plant communities. In a forest ecosystem, photosynthetic physiologico?ecological charac?teristics of its dominant species affects the structure and function of the whole eco?system. The Funiu Mountain National Nature Reserve, sitting in the transitional zone between the north subtropics and the south warm?temperate,has preserved an intact type of forest ecosystem. Quercus variabilis, as its main dominant species in areas of low altitude, regenerates nicely forming distinct layers. Photosynthesis of the plants of different development stages ( arbor, shrub and seedling) was measured with a Li-6400 photosynthetic meter and a fluorimeter in the field, and chlorophyll contents in the plants deter?mined in the laboratory. Results show that ( 1) the plant at its seedling stage is the highest in apparent quantum yield and in chlorophyll content, but the lowest in dark respiration rate and in light compensation point; ( 2) the plant at its arbor stage is the highest in high?light adaptability, but the lowest in chlorophyll content, and does not show any phenomenon of midday depression, and diurnal variation of its net photosynthesis at different layers is mainly governed by light intensity;(3)the plant at its arbor stage is the highest in PSⅡ maximum photochemical quantum yield, while the plant at its seed? ling, the lowest;and ( 4) the plant, regardless of growth stage, is higher in the morning than in the afternoon in stomatal conductance and in transpiration rate;and in water use efficiency, too, at all the stages, except the arbor stage, when it goes reversely. Such divergences of the plant in photosynthetic characteristics with the developmental stage enable it to a?dapt to different environments. That′s why the plants grow nicely at all stages, showing strong regeneration ability and an inherent impetus towards positive succession.