Investigating the effect of atmospheric pollutants on the photosynthesis efficiency of conifers using remote sensing data (Case study: Chitgar region)

The world needs all-round cooperation to reduce environmental pollution. Vegetation can be a way forward in this field. Some pollutants such as carbon monoxide, ozone can cause destructive effects on vegetation for many plants. Conifer forests and some of its species including Pinus halepensis Mill. It has a very good resistance to drought stress and for this reason it is suitable for reforestation in arid and semi-arid areas. In this research, it has been tried to investigate the effects of important pollutants such as nitrogen oxide, ozone and carbon monoxide on coniferous species of Chitgar Forest Park. The results show that the excessive increase of carbon monoxide in the winter season and then the autumn season has a negative correlation with the amount of chlorophyll fluorescence of the sun and a harmful effect for the photosynthesis of coniferous vegetation. Its value is -0.298 mg/m2 with a correlation percentage of 25.63, P-value 0.197, and RMSE value of 9.6 mg/m2. In the winter season, the highest percentage of correlation of pollutants with chlorophyll fluorescence of the sun has been obtained, 16.93% correlation with P-value of 0.013 and RMSE value of 4.7 mg/m2 has been calculated. In autumn, the positive effect of nitrogen oxide is observed, which shows the importance of this element in the chemical processes of plants, including conifers. Due to the prevailing wind in the region, which is from east to west, and its movement towards the Chitgar forest park, elements such as ozone and carbon monoxide enter the leaves through the holes, while destroying the leaf structure on the photosynthesis process of the plant, as well as harmful effects. will enter, and will cause a decrease in the amount of photosynthesis of the area's vegetation. Other side factors also aggravate this problem, especially in the autumn and winter seasons, this will be more pronounced, which will cause more accumulation of ozone and carbon monoxide in the surrounding environment of leaves and plants, including the growth and expansion of urbanization, increasing agricultural activities with Indiscriminate consumption of fuels and environmental pollutants, drought stress, especially in arid and semi-arid regions, delay in the onset of autumn rains, climate change and excessive accumulation of greenhouse gases, resulting in temperature rise, population growth, and similar issues. can be named. A brief survey in Chitgar area shows that in recent years the effect of pollutants on chlorophyll fluorescence values in Chitgar Forest Park Complex has been inevitable and this problem has left a bad effect on the vegetation of this area. And considering the extent of industries in this area, which starts from the west of Karaj and continues to the vicinity of the Chitgar Forest Park Complex, Due to the prevailing wind blowing from the west of Alborz province, these pollutants will move towards Chitgar region and cause damage to the ecosystem of Chitgar area, so that pollutants such as (ozone, carbon monoxide) have a destructive effect on their leaves, and enter the plant structure through the openings and have a negative effect on the chlorophyll and photosynthesis of the vegetation of the region.