Citra Gilang Qur’ani of the Department of Forestry, University of Muhammadiyah Malang conducts mangrove research in Bali, Indonesia Agus Muhamad Maulana/CIFOR-ICRAF

The Indo-West Pacific Region, which includes East Asia, hosts the most diverse mangrove ecosystems in the world. Their distribution area is gradually expanding, and migrating, owing to climate change.

To better understand this phenomenon and learn how to maintain healthy mangrove systems, researchers with the National Institute of Forest Science (NIFoS) in the Republic of Korea have been working with the Center for International Forestry Research and World Agroforestry (CIFOR-ICRAF), Indonesia’s National Research and Innovation Agency and Udayana University in Denpasar, Bali Province.

The Korean Peninsula is in the northernmost sub-tropical climate zone. Two species of semi-mangrove trees grow there, including on the southernmost Jeju Island, and their range has been expanding incrementally as temperatures increase, indicating potential for true mangroves to be established in Korea. The island of Bali in Indonesia is home to healthy sites of planted and extant mangrove forests, particularly, the 1373 hectares (ha) of the I Ngurah Rai Great Forest Park near the international airport.

“Conservation and restoration of coastal and marine ecosystems is a promising approach to address climate change,” said Ni Luh Watiniasih, Dean of the Faculty of Mathematics and Natural Sciences at Udayana University. “These ecosystems, known as blue carbon, have the ability to sequester and store substantial amounts.”

Watiniasih was speaking at an international symposium, Beyond Blue Carbon: Climate Change Adaptation and Mitigation with Blue Carbon: Cross-sectional Research from Two Islands, held 27 March 2023 in Denpasar.

Lanang Aryawan, deputy head of the Forestry and Environment Agency for Bali Province, explained the history of the Great Forest mangrove park: “In 1973, part of the Benoa Bay mangrove forest was illegally cut for firewood. Given that the mangroves were extensively damaged, in 1974 the Government granted a 20-year licence for reforestation, with an intercropping system, covering 306 ha. Ten years later, however, the area had become largely converted to intensively managed fish-ponds. In 1988, the Minister of Forestry revoked the licence and two years later, the Governor of Bali issued an instruction to reforest the pond area by at least 100 ha per year, implementation of which was supported from 1992 to 1999 by the Japan International Cooperation Agency, funding the planting of mangroves on 189 ha. In 2001, the Mangrove Information Center was built along with other ecotourism facilities.”

Sang-hyun Lee, head of the Jeju Island branch of NIFoS, noted that he hoped Korea could learn much from Indonesia about the preservation and management of mangroves, which was a major driving force behind the decision to conduct a research project examining the two islands’ mangrove systems, especially, the successful restoration.

Bora Lee, a research scientist with NIFoS Jeju and leader of the project, said that, “The objectives of this project are to identify the carbon-sequestration capacity of mangrove species native to East Asia and to identify species with a high potential for successful application in Korea as future carbon sinks. Additionally, this research aims to characterize the growth patterns of mangrove species by region, habitat condition and species and to develop management strategies and a stable propagation protocol in the most suitable growing areas.”

A team from NIFoS have been measuring Bali’s mangroves to evaluate the possibility of introducing species to Korea and the characteristics of specific locations along with propagation techniques and species’ uptake capability, and valuation, of carbon.

“We have already measured the carbon uptake of the semi-mangroves in Jeju,” said Lee. “They store nearly double the amount of carbon than the island’s deciduous trees, shrubs and soils. We are here to learn if Bali’s true mangroves are similar.”

Despite Indonesia holding 3.36 million hectares of mangroves — about 23% of the world’s total — they remain under heavy threat from human need for livelihoods, according to Budi Leksono, senior researcher with the National Research and Innovation Agency (BRIN).

“The best course is, indeed, to rehabilitate mangrove areas to their original state with a management model that aligns conservation with economic activities to meet the needs of people. We already are testing a number of models and we are looking forward to sharing experience with the team from Jeju.”

Ketut Subandi from the provincial Forestry and Environment Agency explained that mangrove restoration was now embedded in the provincial government’s policy, as part of the concept of unification of the soul, earth, water, animals and plants, culture and the universe.

“It’s important that policies support an integrated approach to mangroves because so many factors are interlinked,” said Subandi.

Made Saka Wijaya from Udayana University and Putu Angga Wiradana from Dhyana Pura University provided background to the extent of research to date carried out by the two local universities, which included technical approaches to monitoring biodiversity, carbon, water, soils, air quality, temperature and humidity, as well as ecosystem services that underpin human wellbeing, such as provision of conditions for ecotourism, which returns economic benefits from maintenance of healthy mangroves, and provision of phytopharmaceuticals that can help address various health conditions and diseases.

“Development of the potential of phytopharmaceuticals, however, faces a lot of challenges, like shortage of raw material, substandard processing, pest and disease attacks and pollution by plastics and heavy metals,” said Wiradana.

Mihyun Seol, a NIFoS scientist seconded to CIFOR-ICRAF, explained that future research will focus on identifying species with high carbon storage capacity for restoration, with an expectation of establishing restoration sites in 2024.

“We are also exploring more funding opportunities so as to expand research beyond carbon to include ecosystem services and biodiversity conservation,” said Seol.

The urgency of restoring mangroves with the knowledge and skills we have already at hand while conducting research to gain more knowledge was emphasized by Himlal Baral, co-project leader and senior restoration scientist with CIFOR-ICRAF.

“The project and this symposium are revealing more and more details of the riches of mangrove forests,” he said. “We need to preserve those existing and restore those that have been lost so that we can all benefit in ways that will enrich not only the present generation but those to come.”

The closing session of the symposium featured presentations by Sigit Sasmito, Citra Gilang, Agus M. Maulana and Chanwoo Park on restoration opportunities; data analyses and findings; mapping and site selection; and understanding field surveys and protocols, respectively.

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For more information, please contact Himlal Baral (h.baral@cifor-icraf.org).

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This research was supported by the National Institute of Forest Science, Republic of Korea and collaborated with National Research and Innovation Agency (BRIN), Republic of Indonesia , and the University of Udayana.