Seasonal Photosynthesis Variations of Dominant Tree Species Used in Different Urban Landscapes

Photosynthesis is the only natural process that converts photon energy into chemical energy, and it is responsible for 90–95% of plant biomass accumulation and hence growth. Environmental factors such as light, temperature, and CO2 concentration in the atmosphere are major factors that influence photosynthesis, and excess of these can cause stress on plants. The photosynthetic response of tree species is found to vary to these factors. Therefore, the photosynthetic response of tree species can be a good indicator to assess these environmental factors that are changing due to urbanization and can be used to mitigate these factors as well by cultivating suitable tree species. The present study provides information on the seasonal variations in photosynthetic activity in six tree species. In the present study during the month of May (late summer to early monsoon) most of the tree species showed higher photosynthetic rates. It is also noticed that transpiration rate and water use efficiency was more in the month of May compared to other months. An increase in net photosynthesis and transpiration is observed among the tree species under high rainfall conditions 285.2 mm. It is also observed that photosynthesis decreased where the evaporative demand is very high.