Abstract:

Aims: The evaluation of living plant collections is critical for botanical garden to formulate conservation strategy and future development plans. This paper studies the current geospatial distribution of Guangdong botanical gardens and their status quo and problems of ex situ collections of plant diversity, aims to provide references for an updated conservation strategy of South China National Botanical Garden, a conservation network of Guangdong botanical gardens and the development of China’s national botanical gardens system.

Methods: On the basis of investigation, we identify the geographic locations and vegetation zones of the all 15 botanical gardens in Guangdong Province with reference to the literature analysis of Chinese vegetation and Guangdong vegetation. According to the plant lists provided by the 12 botanical gardens, we quantify the living plant diversity in ex situ collections, analyze phylogenetic bias, threatened species representation and useful plant composition by synthesis of updated taxonomy, conservation categories and economic uses.

Results: (1) There is an obvious bias in the distribution of Guangdong botanical gardens from the natural vegetation areas. The gardens are only located in the south subtropical monsoon evergreen broad-leaved forest zone and the north tropical semi-evergreen monsoon forest zone, but no one in the middle subtropical zone. (2) We reveal that the Guangdong botanical gardens manage at least 15,026 species, belonging to 3,030 genera in 329 families. Of which, there are 9,068 vascular plant species native to China, belonging to 2,131 genera in 275 families, equating to 23% of the known vascular plant diversity in China. (3) Phylogenetic analysis indicates that the Guangdong botanical gardens hold a remarkable degree of taxonomic coverage within ex situ living collections for Guangdong native vascular plants, accounting for 95% of the family, 80% of the genera, and 58% of the species, respectively. (4) The analysis of threatened status and key conserved species shows that the Guangdong botanical gardens preserved 64% of the provincial threatened vascular plants native to Guangdong, and 83% of the wild vascular plants distributed in Guangdong Province and listed in the List of National Key Protected Wild Plants (version 2021). (5) The analysis of useful plant collections shows that the Guangdong botanical gardens held 72% of the vascular plants in Guangdong Province in ex situ living collections, covering all the useful categories that are currently common, and the resource preservation rate of each category exceeds 69%.

Conclusion: The results indicate that Guangdong botanical gardens play an important role in plant diversity conservation, but they should be integrated with in situ conservation institutions and adopted an updated conservation strategy to enhance future biodiversity conservation. We put forward some suggestions: (1) improving the regional ex situ conservation network system, with the South China National Botanical Garden as the core, geographical distribution of ex situ institutions and their integration with the natural reserve system. (2) building a comprehensive preservation capacity system for national collections, focus on increasing research collections of key taxa, undertake conservation collections of priority threatened species and coordinate core collections of germplasm, to expand both conservation efficiency and the utilization of wild plants resources. (3) establishing an experiment research system of “nursery cultivation-artificial community-inter situ planting” for key endangered species, implement an integrated conservation research plan, and promote plant diversity conservation, scientific research and sustainable use.

Key words: botanical garden, living collections, ex situ conservation evaluation, plant diversity, integrated conservation strategies