The impact of human activities on the mangrove forests of the Qeshm Island, Iran

Abstract

This article investigates the human impact on the mangrove forest in the Qeshm Geopark on the Qeshm Island in the south of Iran from 1986 to 2020. The area of mangrove forests increased by 14% from 5,131 hectares in 1986 to 5,472 hectares in 2000, and to 5,967 hectares in 2020. The mangrove forest is threatened by oil and gas facilities and a zinc smelter located on the island. The average concentration of nickel in sediment (97.2 μg/g) and in leaves (3.1 μg/g) was higher than the average concentration of vanadium in sediment (38.7 μg/g) and in leaves (0.5 μg/g). The results showed that the transfer coefficient of nickel and vanadium from root to leaf on the dry side of the Qeshm habitat (r = 0.597 and r = 0.516, respectively) was positively correlated with pH. Therefore, increasing the pH leads to an increased metal transfer from the root to the leaf, which endangers the mangrove habitat on the island. The mangrove forest in the vicinity of the zinc factory is threatened by high concentrations of lead (244.2 ppm), zinc (3172.8 ppm), arsenic, and cadmium found in the soil sample.