虉草光合作用日变化及其与环境因子的关系

Diurnal change of Phalaris arundinacea photosynthetic characteristics and its relations with environmental factors.

对镇江北固山湿地优势植物——虉草的光合作用进行了试验研究。结果表明,春夏季晴天虉草净光合速率(Pn)的日变化为双峰曲线,有明显的光合“午休”现象;多云天虉草的Pn主要受光强制约,随光合有效辐射(PAR)变化而变化。经统计学验证,虉草的Pn与PAR、气孔导度(Gs)有显著正相关关系,而与细胞间隙CO_2浓度(Ci)呈显著负相关。用一元二次方程拟合了虉草的光响应曲线,得到光补偿点为38.572μmol·m^(-2)·s^(-1),光饱和点为2087.5μmol·m^(-2)·s^(-1)。

The study on the photosynthetic characteristics of Phalaris arundinacea, the dominant plant in Beigu Mountain wetland, showed that on sunny days in spring and summer, the net photosynthetic rate (P_n) of P. arundinacea had a diurnal change with two peaks, exhibiting an obviously phenomena of midday depression, while on cloudy days, the P_n was mainly affected by light intensity. The P_n was positively correlated with photosynthetically available radiation (PAR) and stomatal conductance (G_s), while negative...