濒危植物香果树不同生境下光合荧光特性的比较

Comparison of Photosynthetic and Fluorescence Characteristics of the Endangered Plant Emmenopterys henryi in Different Habitats

为了探讨不同生境香果树光合特性的差异,采用室内试验和野外试验相结合的方法,研究了香果树幼苗光合特性和宝天曼自然保护区、青苔关林场、武夷山国家公园三种生境下香果树自然种群的光合及荧光特性。结果表明:(1)香果树幼苗光饱和点为400μmol·m^(-2)·s^(-1),CO_(2)饱和点为1200μmol·mol^(-1),日变化为双峰曲线,存在有明显的“午休”现象;(2)纬度越高香果树净光合速率越低,树龄越大香果树净光合速率越高;蒸腾速率随树龄增加呈增加趋势;3~10年龄香果树的气孔导度最高;(3)随纬度增加香果树PSⅡ有效光化学效率增加,电子传递效率和非光化学淬灭减少;青苔关林场和武夷山国家公园香果树光化学淬灭系数显著高于宝天曼自然保护区。纬度高低显著影响香果树光合特性是导致香果树种群年龄结构不同的关键因子,高纬度地区可以采用栽植种苗增加种群幼苗数量,低纬度地区可以通过间伐降低冠层遮荫促进幼苗生长,保证香果树自然更新。

In order to protect the endangered plant Emmenopterys henryi and promote its population recovery and self-renewal,the photosynthetic properties of greenhouse cultured E.henryi seedlings were studied,including light response curve,CO2 response curve and diurnal variations of photosynthetic rate.The photosynthesis and fluorescence properties of E.henryi were studied in Baotianman Nature Reserve,Qingtaiguan Forestry Farm and Wuyishan National Park.The results showed that:(1)The light saturation point of E.henryi seedlings was 400μmol·m^(-2)·s^(-1),the CO_(2)saturation point was 1200μmol·mol^(-1),the diurnal change was a bimodal curve and had obvious"lunch break"phenomenon;(2)The photosynthetic rate of E.henryi decreased with increasing latitude,the photosynthetic rate and transpiration rate of E.henryi increased with tree age;Among them,the stomatal conductivity of 3~10 years old E.henryi was highest;(3)As latitude increases,the effective photochemical efficiency of PSⅡin E.henryi increased,while the electron transport rate and nonphotochemical quenching decreased;The photochemical quenching of Qingtaiguan Forest Farm and Wuyishan National Park was significantly higher than that of Baotianman Nature Reserve.Latitude significantly affected the photosynthetic characteristics of E.henryi.Latitude was a key factor that significantly affected the age structure of population on E.henryi.