On August 17, 2024, a small group of villagers from Patho District in Chumphon Province undertook a survey of Lam Huai Phra, a tributary of Khlong Yae.
This community-driven exploration, aimed at understanding the biodiversity of a stream located near the proposed route of Thailand’s landbridge construction, reflects growing concerns about the potential ecological consequences of this large-scale infrastructure project.
The landbridge is part of Thailand’s ambitious Southern Economic Corridor, intended to connect the Gulf of Thailand with the Andaman Sea.
While modest in scope, the survey area is ecologically and culturally significant. It includes villagers' palm oil and fruit orchards, bordered by thriving upstream forests.
Participants used citizen science methods, an increasingly recognized approach, to study the region’s biodiversity.
Armed with simple tools—nets, magnifying glasses, and basic water quality kits—they measured oxygen and pH levels while cataloging plants, animals, and aquatic life in and around the stream.
This initiative was not just about gathering data; it was a grassroots effort to empower locals with knowledge of natural history and ecosystem services.
These services, including water purification, pollination, and climate regulation, are expected to be disrupted by the landbridge project, which spans 90 kilometers and includes a six-lane motorway and a dual-track railway.
The narrowest segment of the landbridge is planned to be 175 meters wide, while wider sections accommodating service areas could reach 500 to 600 meters. The project also includes tunneling through hilly terrain to complete the route.
A Project of Massive Proportions
The Landbridge project in Thailand, officially named the Southern Economic Corridor Infrastructure Development Project, is envisioned as a transformative initiative aimed at shortening the journey between the Gulf of Thailand and the Andaman Sea.
This modern proposal traces its roots to an older concept of constructing the "Klong Thai," a massive excavation through the Kra Isthmus. The current plan, however, shifts from canals to a land-based corridor.
The Thai government views this endeavor as an opportunity to compete with existing trade routes, particularly the Straits of Malacca, a major artery of global commerce.
With this new route, the government believes Thailand could position itself as a key logistics hub, accelerating its progress toward becoming a high-middle-income or high-income country by 2037.
The project, with an estimated cost exceeding 1.1 trillion baht, has already secured Cabinet approval.
Framed within the broader vision of the Southern Economic Corridor (SEC), Mr. Panya Chupanich, Director of the Office of Transport and Traffic Policy and Planning (OTP), spearheaded the Landbridge project.
He argues that the initiative will attract significant foreign investment. In efforts to secure international backing, former Prime Minister Srettha Thavisin conducted global roadshows, emphasizing the project's ability to reduce transit times through the Straits of Malacca from nine days to just five.
While the process would require double-handling of cargo during transport, supporters of the project assert that its efficiency gains far outweigh these logistical challenges.
It is also expected to increase GDP growth to 5% (from 4.0%) and create a total of 280,000 jobs in the area. (Source: OTP citing the National Economic and Social Development Council (NESDC))
However, its environmental cost remains a contentious issue. Multiple environmental impact assessments (EIAs) and feasibility studies have focused on trade competitiveness, transportation efficiency, and commercial agriculture but have largely overlooked biodiversity and ecosystem services.
Data for these areas is outdated and limited, relying heavily on government databases that focus primarily on national parks and neglect smaller forest patches and unprotected green spaces.
This gap in ecological understanding has spurred concern among researchers, conservationists, and local communities.
Muangpai Suetrong, a first-year conservation biology student from Mahidol University’s Kanchanaburi Campus, joined the Lam Huai Phra survey to assist villagers in documenting their local biodiversity.
An avid birdwatcher and winner of Thailand Bird Fair’s 2024 True Fan Award, Muangpai highlighted the region's unique biodiversity.
"Chumphon and Ranong host species found nowhere else," Muangpai explained, referencing the recently discovered Kra Isthmus Pitviper (Trimeresurus kraensis), an endemic species.
"The biodiversity data for this area is outdated and lacks detail. Even degraded lowland forests in villagers’ orchards will face significant impacts from light and noise pollution, as well as chemical residues. We need thorough studies beforehand to prevent biodiversity loss and reduced ecosystem services, especially amid escalating climate change."
The Ecological Significance of the Isthmus of Kra
The landbridge route runs through the Isthmus of Kra, a globally significant ecotone—a transition zone where the ecosystems of continental Asia meet those of the Malay Archipelago.
This narrow stretch of land serves as a genetic exchange point for flora and fauna, fostering unique biodiversity due to its geographical and climatic features. Seasonal variations in the Kra Isthmus create a distinctive environment, blending subtropical and tropical climates.
Assoc. Prof. Dr. Kittichet Sridit, a botanist from Prince of Songkla University who specializes in coastal and beach vegetation, has studied the vegetation along the proposed landbridge route.
He emphasizes the importance of forest remnants, describing them as critical "stepping stones" for genetic exchange among wildlife populations.
"Forest remnants are like stepping stones enabling genetic exchange," Kittichet explained. "Losing them would diminish genetic diversity, impacting population structures long-term. Natural resources aren’t solely ours; they belong to future generations. Once gone, they’re lost forever."
Kittichet also highlighted the dangers of viewing degraded forests as expendable. While they may appear less significant than pristine environments, they often harbor essential biodiversity, providing habitats for species that cannot thrive elsewhere.
Threats to Biodiversity and Migratory Birds
The Isthmus of Kra is part of the East Asian-Australasian Flyway, one of the world’s most critical bird migration routes.
Approximately 50 million migratory birds pass through this corridor annually, covering 22 countries. The narrow stretch of land in southern Thailand is a vital stopover point for many species.
Ornithologists Dr. Rongrong Angkaew and Mr. Wich’yanan Limparungpatthanakij have studied the potential impacts of the landbridge on migratory birds and their habitats.
The route traverses diverse ecosystems, including beaches, mangroves, and evergreen forests. Many of these habitats support endangered and vulnerable species listed on the IUCN Red List, such as Pale-capped Pigeon, Nordmann’s Greenshank, and Plain-pouched Hornbill.
Additionally, the landbridge project includes the construction of wind turbines in the Lamai National Forest Reserve, which has raised further alarms.
Large raptors, nocturnal migratory birds, and even smaller species are highly vulnerable to wind turbines, as global data shows significant bird mortality rates in areas with high turbine density.
"Large eagles in Central Asia and Eastern Europe are known to die in significant numbers from wind turbines," Wich’yanan explained.
"On our flyway, we see thousands of raptors, such as Oriental Honey-buzzard, passing through. These species are at risk, even though data for smaller birds like the Wwhite-throated Needletail is scarce."
Dr. Rongrong echoed Wich’yanan’s concerns, adding that the lack of ecological data hinders informed decision-making.
"As researchers, we’re frustrated by the lack of government support for ecological studies. It limits our ability to make sound recommendations, and the lack of transparency exacerbates these challenges."
Grassroots Efforts and Citizen Science
Local communities, particularly members of the Rak Patho Network, are stepping in to fill these gaps in data and advocacy.
The group has been conducting citizen science projects to document biodiversity in the proposed construction area. Such initiatives aim to empower locals with the knowledge needed to resist development plans that threaten their environment.
Suchat and Chaloem-usa Srikiao, local business owners and members of the Rak Patho Network, stressed the importance of grassroots knowledge-building.
They launched a biodiversity mapping project on iNaturalist, inviting villagers, tourists, and researchers to contribute data on local flora and fauna.
"Knowing what we have helps us protect it," said Suchat. "If we find endemic species, it proves the area's ecological value and the need for conservation."
Activist Benjawan Tubtimthong, a former kindergarten teacher, criticized the government for its lack of transparency. "I’d give the government’s transparency a score of just 1%," she said.
"They’ve excluded impacted villagers from discussions, inviting only local leaders who often align with the government’s agenda. This isn’t fair. What will we leave for our children if we destroy the environment?"
Benjawan’s son, Thanet, has taken on a pivotal role as the Rak Patho Network’s communications officer. He amplifies the group’s message using digital platforms, shares live updates, and manages the network’s social media presence.
Thanet also launched the "TH-Landbridge BioBlitz" project on iNaturalist, encouraging locals and visitors to document biodiversity in the area.
“Mapping biodiversity shows us what exists in our area and why we shouldn’t destroy its ecosystems,” Thanet explained. “If we identify endemic species tied to this region, it underscores the need for conservation.”
Broader Implications and the Call for Transparency
The Landbridge project reflects a broader trend in Thailand: the prioritization of economic growth over environmental sustainability.
Researchers like Dr. Kittichet and Dr. Rongrong argue that the lack of government support for ecological studies leaves critical knowledge gaps.
These gaps hinder informed decision-making and prevent the integration of biodiversity considerations into large-scale infrastructure projects.
"Ecological studies require years, even decades, to build a comprehensive understanding," Dr. Kittichet noted.
"You can’t expect to gather this knowledge in one or two years when a crisis arises. The idea of offsetting environmental destruction by planting new forests is fundamentally flawed. Natural ecosystems cannot simply be replaced."
Birdlife International’s AVISTEP (Avian Sensitivity Tool for Energy Planning) identifies areas vulnerable to development, and the proposed wind turbine sites in Chumphon fall within red zones.
This designation underscores the urgent need for better planning and transparency.
Wich’yanan summed up the broader challenge: "The government isn’t telling the full story of this project, but I’m hopeful that informed citizens can hold them accountable. The data we’re gathering isn’t just for us; it’s a tool for the community to fight back."
The Isthmus of Kra is not just a narrow strip of land; it’s a critical ecological hub for migratory birds, endemic species, and genetic diversity.
While the landbridge promises economic benefits, its environmental costs cannot be ignored. Grassroots movements, citizen science, and the efforts of researchers are vital to ensuring that this development does not come at the expense of irreplaceable natural resources.
