Examining the growth potential and eco-physiological response of Conocarpus erectus and Morus alba to limestone dust and lead (Pb) pollution

Abstract

The current study aimed to explore the ecophysiological responses of Conocarpus erectus and Morus alba under lead pollution and limestone dust environments. A pot trial was conducted at the Forest Nursery and Experimental Area, Institute of Forest Sciences, The Islamia University, Bahawalpur. The selected tree species were grown under controlled environmental conditions, with 4 treatments including 2 levels of dust (0, 5g) and 2 levels of lead-contaminated water irrigation (0 and 10 mg L⁻¹). The results showed that the growth of both tree species was maximum in the T₁ and minimum in the T₄. The results showed that the M. alba grows better than C. erectus at the same levels of lead and limestone dust contamination. The results showed that under different levels of lead and dust pollution, aspen species effectively destroyed oxidative bursts by triggering SOD, POD, CAT, and MDA contents, and were the most tolerant to lead and limestone pollution. The photosynthetic pigments such as chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids were maximum in M. alba (1.46 mg g^-1 FW, 2.73 mg g^-1 FW, 4.2 mg g^-1 FW, 1.71 mg g^-1 FW) as compared to C. erectus. In conclusion, the M. alba shows a better ability to absorb dust and heavy metals in a polluted environment as compared to C. erectus. The obtained findings will be helpful for future tree crop cultivation in contaminated sites.