Boat-shaped houses of the indigenous Li people on Hainan Island, China: plant resources and ecological adaptations.

Background: The traditional boat-shaped houses of the Li people on Hainan Island, China, reflect centuries of ecological adaptation to the tropical rainforest. These vernacular dwellings are now threatened by rural depopulation and rapid modernization. We explore the ecological function, material use, and cultural value of the boat-shaped houses of the Li people and support their nomination as a site of UNESCO World Natural and Cultural Heritage.

Methods: We combined ethnobotanical surveys, environmental measurements, and literature analysis to evaluate plant-based construction, house-environment interactions, and traditional knowledge.

Results: The study identified four types of traditional boat-shaped houses of the Li people on Hainan Island, constructed using 26 plant species across 13 families. Environmental monitoring showed that in natural conditions, boat-shaped houses had lower indoor air temperatures (by 1.3 °C in Chubao Village), reduced relatively humidity (by 7.3% in Baicha Village), and significantly lower wet bulb globe temperatures (by 9.6 °C in Baicha Village), compared to modern brick houses. Boat-shaped houses thus provided a more thermally comfortable environment than modern brick houses, particularly during the dry season. The results emphasize the green, low-carbon construction cycle of boat-shaped houses and highlight the urgent need to conserve this ecologically sustainable traditional knowledge system.

Conclusions: Li boat-shaped houses demonstrate a low-carbon, climate-adaptive building system rooted in indigenous knowledge. Their preservation offers critical insights for sustainable design and biocultural conservation in tropical regions.