INTRA- AND INTERSPECIES VARIATION IN PHOTOSYNTHETIC ACTIVITY OBSERVED THROUGH OSP 5+ FLUOROMETER DURING LEAF FLUSHING PHASE IN DECIDUOUS FOREST SPECIES

摘要

We investigated intra- and inter species variation in photosynthetic activity of three deciduous forest tree species viz., Kanju (Holoptelea integrifolia), Rohini (Mallotus phillipensis) and Shisham (Dalbergia sissoo) during the leaf flushing phase. The experiment was carried out in Bhakra forest range, Terai Forest Plantation Division, Haldwani, India. In-situ measurements of leaves were taken during summer of 2016 and 2017. The observations were recorded during peak photoperiod 8 hrs to 10 hrs. Results show that photosynthesis rate (Pn) of species is significantly different while intra-species differences shows a smaller amount of differences. OS5p Multi-Mode Chlorophyll Fluorometer recorded higher level of variation than photosynthesis system (CI-340). Positive relationship was observed between photosynthetic rate and chlorophyll florescence decrease ratio (R_(Fd)). Dalbergia sissoo has higher rate of photosynthesis (Pn=16 ± 2.6 and Rd 3.72 ±0.20) than other species.