Species characteristics and cultural value of stone wall trees in the urban area of Macao

The stone walls remaining in the highly urbanized Macao area provide a special habitat for plants, repair the fragmentation of the habitat caused by urbanization, and enhance the urban biodiversity. The main object of this survey are stone wall trees in Macao. The species composition, frequency of occurrence and distribution were ascertained, and the feasibility of establishing stone wall tree landscape trail systems was discussed. The results showed that there were 96 stone wall trees in Macao. Among them, 47.9% of the total in the historical center of Macao. In addition, research and analysis on the species composition, life form, frequency and similarity of the associated plants of stone wall trees were analyzed. The survey found that there were 101 species of companion plants, and herbaceous plants had the greatest growth advantage. Most of the companion species were selective and incidental to the stone wall habitat; the similarity of the companion plants in different habitats was less than 0.25, showing that the stone wall was conducive to species diversity. The results of this research aim to explore planning strategies for holistic conservation of stone wall landscape, and provide a theoretical basis for studying the biodiversity of special habitats in Macao.