TEHRAN –The International Day of the Tropics, observed on June 29 annually, focuses on the significance of the tropics as hubs of the world's biodiversity and the challenges faced by the regions due to climate, geography, and urbanization.

Covering nearly 40 percent of the Earth’s surface, the tropical zone hosts around 80 percent of the world’s biodiversity and a substantial portion of its cultural and linguistic richness.

The Tropics are a region of the Earth, roughly defined as the area between the tropic of Cancer and the tropic of Capricorn. Although topography and other factors contribute to climatic variation, tropical locations are typically warm and experience little seasonal change in day-to-day temperature. 

An important feature of the Tropics is the prevalence of rain in the moist inner regions near the equator, and the seasonality of rainfall increases with the distance from the equator. The richness of the Tropics also makes them central to achieving the United Nations Sustainable Development Goals (SDGs).

By 2050, the region will host most of the world’s people and two-thirds of its children.

However, the tropical region faces several challenges such as climate change, deforestation, logging, urbanisation, and demographic changes.

Consistent with the higher levels of poverty, more people experience undernourishment in the Tropics than in the rest of the world.

The proportion of the urban population living in slum conditions is higher in the Tropics than in the rest of the World.

Countries within this region, spanning parts of Asia, Africa, Latin America, and Oceania, are witnessing rapid population growth and urbanization, but these developments come with pressing issues such as deforestation, habitat loss, pollution, and socio-economic inequality.

Moreover, the Tropics host nearly 95 percent of the world’s mangrove forests by area and 99 percent of mangrove species. 

The mangrove tree, as a wonder of the marine environment, offers many benefits to various species, including birds, fish, crustaceans, and even some terrestrial animals, and stabilizes the soil, as well. Mangrove forests are rich ecosystems that support the planet and humanity in unique ways by providing conditions for fish growth, storing carbon, and fighting floods.

According to a study by researchers at the National Institute of Oceanography, mangrove ecosystems in the northern Persian Gulf are facing a range of environmental and anthropogenic pressures.

Mangrove forests in Iran mostly consist of the Avicenna marina, known as Hara, named after the 11th-century great Iranian scientist Avicenna, or Abu-Ali-Sina.

The study assesses the ecological dynamics of the Mangroves of Dayyer City (MDC) in the northern Persian Gulf using a multidimensional approach involving satellite-derived, drone-based, and field-measured data.

Satellite imagery from Google Earth (2011–2022) reveals fluctuations in the MDC area, with notable afforestation efforts until 2018, followed by rapid degradation. 

The mangrove forest, initially covering 2.2 hectares in 2011, expanded to 3.2 hectares by 2015 due to afforestation efforts but declined to 1.7 hectares by June 2022.

The construction of a nonstandard road and a bridge in 2018 obstructed freshwater flow from upper areas, emerging as a major factor responsible for the degradation.

Drone-based observations in March 2023 provided a detailed map, revealing that 44 percent of healthy mangroves had been damaged. Field measurements conducted in November 2023 showed higher salinity levels at MDC compared to other adjacent mangrove areas.

Principal component analysis (PCA) also demonstrated differences in the environmental conditions of the MDC compared to those of the two habitats sampled (Nayband and Melgonzeh). 

The study suggests that long-term, multi-stressor monitoring, especially at different points within the mangrove ecosystem, is essential for effective management. 

The research also stresses the critical need to address human-induced threats to mangrove ecosystems. Urgent conservation and management strategies are essential for mitigating the impact of anthropogenic pressures and ensuring the survival of mangrove ecosystems in the face of environmental challenges.

Moreover, the climate change impacts must be considered when planning conservation and management strategies.

Rising temperatures and sea levels, along with increased salinity, pose long-term threats to mangroves. 

Therefore, developing integrated conservation strategies that combine restoration efforts with the mitigation of both human-induced and climate-related stressors to enhance the resilience of mangrove forests is essential.

MT/MG