ILOILO CITY: A mangrove scientist here has underscored the need to protect and preserve mangroves to fight greenhouse gas emissions as his study revealed their potentials “to store more carbon than terrestrial forest.”
“Mangroves are now highlighted as a major carbon sink in relation to the greenhouse gas emission for climate change mitigation,” said Rex Sadaba of the University of Philippines-Visayas who conducted the study from May to August this year.
Carbon sinks remove carbon dioxide from the atmosphere. “They sequester carbon dioxide and make that into their leaves, into their stem and keep it into their biomass,” he added.
“When the leaves fall, they accumulate into the soil and overtime it is accumulating, the area becomes a sink for carbon. The moment we remove the mangroves here, we increase the decomposition of the organic matter that increases the release of the carbon dioxide back to the atmosphere,” he explained during a roundtable discussions of Iloilo City public-private partnerships last week.
The study “Carbon storage of mangroves in Iloilo and Batiano rivers” conducted this year was the “first ever carbon sink study in the Philippines,” said Noel Hechanova of the City Environment and Natural Resources Office-Iloilo City in an interview also last week.
The study covered 44.56 hectares of mangroves, composed of 27.64 hectares from the Iloilo River and 16.92 from the Batiano River.
Batiano River, which hosts 19 mangrove species, has 18,491.83 tons of carbon sink while it has a potential to emit 67,865 tons of carbon dioxide.
The Iloilo River, which has 23 species of mangroves, has sequestered 34,554.78 tons of carbon and its potential carbon dioxide release is 129, 817.7 tons.
“Above the ground biomass and carbon is high but the carbon stored in the soil is much higher as a result of accumulation overtime,” Sadaba’s study concluded.
Citing the potential, Sadaba underscored the need to “keep the mangroves intact.”
He recommended the active involvement of stakeholders for the continued protection of mangrove areas and information education campaign.
Also, his study recommended that mangroves be allowed to grow further to “maximize biomass for carbon capture.”
He emphasized that mangrove species should not be trimmed because they are not ornamentals. Trimming then would mean releasing the carbon that they capture.
According to him, it is always possible to replant destroyed species but their capability to store carbon is also affected. Mangroves at the Iloilo River are estimated to be not less than 50 years old.
Sadaba estimated that some 0.3 hectare of mangrove, particularly situated in Barangay Inday in this city, was affected by the ongoing development in the Iloilo River.
It is one of the “models” being developed in the city in promoting energy efficiency in the context of greenhouse gas emission reduction, which is climate change-related, Hechanova said.
The campaign is being assisted by the United States Agency for International Development (USAID) through its Be Leaders (Building Low Emission Alternatives to Develop Economic Resilience and Sustainability) Project and implemented by the Research Triangle Institute (RTI) based in North Carolina.