Long-Term Heavy Metal Retention by Mangroves and Effect on Its Growth: A Field Inventory and Scenario Simulation

Area of Science:

• Environmental Science
• Ecology
• Biogeochemistry

Background:

• Mangroves mitigate heavy metal (HM) pollution by uptake and storage.
• However, HMs negatively impact mangrove growth and ecosystem health.
• Rhizophora apiculata forests face long-term soil HM enrichment challenges.

Purpose of the Study:

• Assess the long-term effects of soil HM enrichment on Rhizophora apiculata forest growth.
• Analyze the influence of environmental factors like salinity, elevation, and tree density.
• Develop a predictive model for mangrove dynamics under varying HM pollution levels.

Main Methods:

• Collected novel field data on mangrove growth and environmental conditions.
• Analyzed data to calibrate and validate a tree growth model.
• Performed scenario simulations to predict forest biomass under different HM pollution levels.

Main Results:

• Total forest biomass projected to decline from 1,750,000 tons (no HM pollution) to 850,000 tons (current HM pollution) and 350,000 tons (double HM pollution).
• Environmental factors (salinity, elevation, tree density) interact with HM content to influence growth.
• Simulations demonstrate significant negative impacts of high HM pollution on mangrove health.

Conclusions:

• While mangroves aid in HM remediation, excessive pollution severely degrades ecosystem quality and health.
• A data-and-model driven tool is developed for sustainable mangrove resource management.
• Urgent need for managing HM pollution to preserve mangrove ecosystem integrity.