Living heritage: How ancient buildings on Hainan Island sustain hidden plant diversity

On Hainan Island, centuries-old masonry supports an unexpectedly rich diversity of epilithic, or rock-dwelling, plants, highlighting a close intersection between cultural heritage and natural biodiversity. By integrating island-wide field surveys with statistical modeling, the team demonstrates how geographic gradients, architectural features, and human activities jointly shape these often-overlooked plant communities, offering new scientific evidence to support more balanced and ecologically informed strategies for heritage conservation.

Rapid urbanization across China has placed increasing pressure on historic architecture, particularly in tropical regions where heat and humidity accelerate material decay. At the same time, walls, roofs, and stone surfaces of ancient buildings provide microhabitats for vascular plants, ferns, and climbers. These epilithic plants can regulate humidity, temperature, and surface conditions, sometimes slowing weathering processes, while in other cases accelerating physical or chemical damage. Despite their dual role, most previous studies focused on single sites or cities, leaving large-scale patterns and drivers poorly understood.

A study (DOI: 10.48130/tp-0025-0033) published in Tropical Plants on 26 December 2025 by Hua-Feng Wang’s team, Hainan University, demonstrates that ancient masonry functions as a unique and ecologically significant habitat where geographic and human factors jointly shape epiphytic plant diversity, providing a scientific basis for balancing biodiversity conservation with the sustainable preservation of cultural heritage.

Using a combination of systematic field surveys and multivariate statistical analyses, the study first quantified the physical characteristics, spatial context, and biological assemblages associated with ancient masonry across Hainan Island, and then applied comparative statistics and linear regression models to identify patterns and driving factors of epiphytic plant diversity and abundance. Specifically, researchers surveyed 44 historic structures, recorded their architectural attributes (age, footprint, type, height), surrounding socio-economic and environmental variables, and conducted comprehensive inventories of epiphytic plants, followed by ANOVA tests, temporal comparisons, and multiple linear regression modeling. The survey revealed that most sampled buildings dated to the 15th–16th centuries, averaged 8,072 m² in footprint, and were dominated by residential architecture, with the majority located in suburban and rural areas, reflecting both Hainan’s multicultural history and the effects of urbanization on heritage preservation. Spatial analyses showed that although suburban sites exhibited slightly higher species richness, no significant differences in epiphytic diversity were detected among urban, suburban, and rural settings, nor across different historical periods, indicating that ancient masonry functions as relatively independent ecological units. Floristic surveys identified 25,614 individual epiphytic plants belonging to 255 species, 196 genera, and 80 families, dominated by Moraceae and several fern families, with Ficus pumila as the most abundant species. Functional trait analyses demonstrated a strong dominance of herbaceous, perennial, wild, and native species, with ornamental taxa prevailing and a smaller subset possessing edible value. Regression models further revealed that species richness and abundance were significantly shaped by geographic and anthropogenic factors: longitude, building area, building age, local economic development, and surrounding commercial activity were positively associated with epiphyte diversity, whereas annual passenger traffic consistently showed strong negative effects. Taxon-specific analyses highlighted that different functional groups responded to distinct drivers, underscoring the complex interplay between geography, architecture, and human disturbance in structuring epiphytic plant communities on ancient masonry.

The findings reframe ancient architecture as a form of “vertical green space” with conservation value. Carefully managed epilithic plants can enhance microclimates, contribute to urban biodiversity, and preserve native flora that is increasingly rare elsewhere. At the same time, unchecked growth—especially of large or aggressive species—can threaten structural stability. The study provides a data-driven foundation for selective management, promoting beneficial native species while controlling high-risk plants.

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References

DOI

10.48130/tp-0025-0033

Original Source URL

https://doi.org/10.48130/tp-0025-0033

Funding information

This research was supported by the National Natural Science Foundation of China (Grant Nos 32560290 and 32160273).

About Tropical Plants

Tropical Plants (e-ISSN 2833-9851) is the official journal of Hainan University and published by Maximum Academic Press. Tropical Plants undergoes rigorous peer review and is published in open-access format to enable swift dissemination of research findings, facilitate exchange of academic knowledge and encourage academic discourse on innovative technologies and issues emerging in tropical plant research.