The South China National Botanical Garden, the world's largest subtropical botanical garden and China's second national botanical garden, has been officially unveiled on July 11, 2022. Photo: courtesy of the South China National Botanical Garden

The South China National Botanical Garden, the world's largest subtropical botanical garden and China's second national botanical garden, has been officially unveiled on Monday in Guangzhou, South China's Guangdong Province, a move that experts believe constitutes great significance in preserving biological diversity. 

With the plants ranging from tropical rainforest species to alpine and desert plants, the botanical garden is home to over 17,000 species of ex-situ plants - those transferred from their habitat - including 643 species of rare and endangered plants and 337 species of national key protected wild plants. 

China announced at the leaders' summit of the 15th meeting of the Conference of the Parties to the Convention on Biological Diversity (COP15) last October that acting by the principle of striking a balance between in-situ (near the plant's habitat) and ex-situ plant conservation, China had started building a system of national botanical gardens in places like Beijing and Guangzhou. The Beijing garden was unveiled on April 18. 

The species of plants that can be conserved in Guangzhou differ greatly from those in the Beijing garden, Wang Zhonglang, a research fellow with the Kunming Institute of Botany of Chinese Academy of Sciences, told the Global Times on Monday. 

According to Wang, the geographical layout of botanical gardens depends on different climate zones, thus the two gardens are focused on different plant species.  

As one of the countries with the richest plant diversity in the world, China has more than 37,000 known species of land plants, accounting for about 10 percent of the total in the globe. 

The establishment of a national botanical garden system will enable the country to collect and completely preserve wild plant groups, maintain plant diversity and benefit humanity in the long term, according to a statement on the opening ceremony the garden shared with the Global Times on Monday. 

Apart from climate, the geographical layout of the national botanical gardens is also related to talents and the financial support of the local government, according to Wang. 

The new garden was established on the basis of the South China Botanical Garden of the Chinese Academy of Sciences (CAS), which has been engaged in the work of conservation, scientific research and knowledge dissemination about plants since 1929. 

With a total area of 319 hectares, including the exhibition section and the research section, the botanical garden has 38 specialized gardens for 17,168 classified species of ex-situ conservation, three research centers, one museum of plant specimens, two field research bases and three key laboratories.

Taking the ex-situ conservation of plant resources from South China and global tropical and subtropical regions as the core, the botanical garden has conserved more than 20,000 species of plants including 6,000 species of plants with economic value, with 95 percent of rare and endangered plants in South China conserved through translocation. 

Biological diversity is a task for the future since even if the uses for these plants is not known at the present, they should be preserved for future use, Wang said. Taking the conservation of desert plants for an example, they can be used to help control desertification in the future. 

In terms of the significance of in-situ and ex-situ conservation, Wang pointed out that one cannot be emphasized to the detriment of the other. A botanical garden that offers both types of conservation can protect more plants at lower costs. 

From the perspective of China's geographical distribution of plants and other aspects, Wang believes more national botanical gardens should be built since plants from high-altitude areas cannot be relocated to low-altitude areas.