用Reinecke盐液曝光计检测树冠内的光合有效辐射

Detection of photosynthetic effective radiation (PAR) in tree canopy by Reinecke salt actinometer.

1 引言 传统的植物光合生理生态研究中,多用照度计来测定光照指标,它以人眼对光亮度的响应特性为基础,与植物叶片对光照的响应曲线差异很大;

According to the principles of photochemical reaction and the ecophysioiogical characteristics of photosynthesis of tree leaves, the relative distribution of photosynthetic effective, radiation (PAR) in any position of tree canopy is detected by photochemical reaction actinometer with a solution of 0.01M Reinecke salt {ammonium reineckate, ammonium tetrathiocyanodiammonochromate, NH_4[Cr(NH_3)_2(SCN)_4]·H2O}. The effective absorption wavelengths are as wide as 350—750nm and meet the demand for PAR in tree leaf photosynthesis. The new technique is reliable, simple, convenient, and practical without any damage to the vegetative or reproductive organs of tree canopy. It is superior to the traditional methods (e. g. using photometer, radiometer, quantometer) in representativeness and repeatability. Therefore, it is appropriate for studying the photosynthetic eeophysiological phenomenon in tree population.