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GOING PLANT BASED

China intends to create a national network of botanical gardens to improve conservation, but some botanists believe the approach should be more localized

By Wang Yan , Du Wei Updated Jun.1

Visitors photograph giant Amazon water lilies at Beijing Botanical Garden, August 1, 2020

On April 18, China’s first National Botanic Garden was unveiled in Beijing. Covering around 600 hectares, it will collect more than 30,000 typical and endangered species, about 10 percent of the world’s total, for off-site conservation and scientific research. It now holds 15,000 living species of plants. The National Forestry and Grassland Administration of China says more national botanic gardens will be built. 　

Covering an area of 207 hectares, Chenshan Botanical Garden opened in Shanghai in April 2010. The garden focuses on plant species native to eastern China. It has a collection of 18,000 plant species of 1,945 genus under 260 families, and three national germplasm banks for Lamiaceae (mint and sage family), lotus and ferns. According to Chenshan media representative Zhang Zhe, officials from the National Forestry and Grassland Administration visited the park in mid-February to help the park make the needed upgrades to become a national botanical garden. 
　
Botanists told NewsChina the primary aim of establishing a network of botanical gardens is to improve ex-situ or off-site conservation – conserving species away from their natural habitat. 

Planting the Seed
During the Fifteenth Meeting of the Conference of the Parties of the United Nation’s Convention on Biological Diversity (CBD COP15) held in Kunming, capital of the southwestern province of Yunnan in October 2021, Chinese President Xi Jinping announced in his keynote speech via video link a plan to construct national botanical gardens across China to integrate in-situ (in the natural surroundings) and ex-situ conservation. 　

Xu Zaifu, a botanical expert and former director of the Yunnan-based Xishuangbanna Tropical Botanical Garden of the Chinese Academy of Sciences (CAS) said that by the 1990s, China had already conserved 80 percent of its first batch of nationally listed rare and endangered plants in ex-situ locations. Xu stressed the most urgent task is to improve the level and effectiveness of plant ex-situ protection. “Our government should understand that it is superficial to be satisfied with how many botanical gardens we have and how many plants have been collected,” Xu, speaking from Yunnan, said during a recent telephone interview with NewsChina. 　

Sun Weibang, director of the Kunming Institute of Botany, CAS, told NewsChina that ex-situ conservation does not mean introducing all species into a botanical garden, but conducting onsite research into acquiring those that demand conservation first, and to consider the standards and guidelines of ex-situ conservation. “Just collecting lots of plants doesn’t equate to better ex-situ conservation,” Sun said. 　

Ex-situ conservation aims at protection, which can refer to the cultivation and preservation of living plants in botanical gardens, as well as germplasm banks to preserve plant seeds, tissues and organs. The most conventional and effective method for ex-situ conservation is to cultivate a plant species and establish a plant park or designated area. Wen Xiangying, senior engineer of the South China Botanical Garden in Guangzhou, told NewsChina the priority for ex-situ conservation are “3E” plants – endangered, endemic or with economic value. 　

In 1985, the first International Conference on Botanic Gardens and the World Conservation Strategy was held in Spain to link botanical gardens with biodiversity conservation, making ex-situ conservation an important task of botanical gardens. In recent years, the concept of comprehensive conservation has come to the fore, a combination of ex-situ and in-situ conservation and reintroduction. No single conservation approach is likely to be completely successful due to the diversity and complexity of factors threatening biodiversity. 　

From the late 1980s, the number of botanical gardens in China grew rapidly from around 70 to about 200 by 2005, with an average increase of four each year. According to a commentary titled “Expanding the role of botanical gardens in the future of food” published in online journal Nature Plants in June 2015, the world’s more than 3,000 botanical gardens cultivate approximately one-third of known plant species. China boasts over 36,000 species of higher plants, and up to 200 botanical gardens conserving around 23,000 species. The country has around 10 percent of the world’s total of “higher” or vascular plants – the group that includes tissues for conducting water and minerals, like flowering plants and conifers. It also has about 10 percent of the world’s botanical gardens. Some 60 percent of China’s native plants are conserved in ex-situ locations. 

A visitor takes a photo of an endangered orchid species at Beijing Botanical Garden, October 3, 2021


Site Selection
Beijing Botanical Garden lies at the foot of the Fragrant Hills in western Beijing, covering an area of 231 hectares. Its collection includes more than 10,000 species of plants and their varieties. Across the street is the Institute of Botany, CAS, a botanical garden of 74 hectares which has a collection of over 7,000 species and varieties of plants. Both gardens were established in 1956 and are commonly referred to as the north and south park. 　

The new national botanical garden in Beijing would merge the two gardens and expand them to about 600 hectares. According to Wang Kang, curator of Beijing Botanical Garden’s science museum, the north park is for horticultural display and popular science education, while the south park focuses on research and species protection. He emphasized that the major goal of national botanical gardens based on these two focuses is to strengthen ex-situ protection. 　

Wang Kang said Beijing was chosen for the national garden because it is a symbol of national image and as a channel to promote popular science, as the north park already receives around four million annual visits. It would be an ideal place to collect and conserve plants of the north temperate zone (Tropic of Cancer to the Arctic Circle), and there is scientific support from the Institute of Botany, CAS. 　

About 20 percent of the first batch of key protected plants in China have not been conserved in situ, mostly those from alpine, subalpine and frigid temperate zones, or arid and semi-arid regions. Sun Weibang said constructing botanical gardens requires enormous investment. This means taking into consideration the local natural environment, social and economic conditions, scientific and technological support, transportation and other factors. 　

That is why most botanical gardens in China are in the developed central and eastern coastal areas, rather than the economically underdeveloped southwestern region where the richest plant biodiversity is. Globally, the situation is the same. Xu said there are 28,000 plant species in Europe and North America, less than 10 percent of the world’s total, however there are about 900 botanical gardens in those developed countries, accounting for over half of the world’s total. In South America, there are 90,000 plants but less than 100 botanical gardens. 　

Some academics have raised concerns over the choice of Beijing for the national garden. Liu Huajie, a philosophy professor at Peking University and member of the board of directors of the China Wild Plant Conservation Association highlighted his concerns in an article titled “Site Selection for National Botanical Garden in China Should be Prudent” published on the website of China Biodiversity Conservation and Green Development Foundation in mid-January. He wrote that high latitude and low precipitation in Beijing limit the number of plants that can grow well outdoors. In addition, the high costs of expanding, operating and maintaining the site in a big city like Beijing is a disadvantage. 　

Xu Zaifu agrees with Liu. He believes that from the perspective of scientific significance and effective ex-situ conservation, sites for botanical gardens should be far from big cities and take into consideration proper natural habitats and the availability of insects and birds for pollination. 

“It’s much better to choose places with rich biodiversity, preferably close to a nature reserve or large areas of natural vegetation,” Xu said. “This way, we can combine in-situ, ex-situ protection and reintroduction and avoid big differences in the ecological environment [of transplanted species] and excessive human intervention.” 　

Addressing these concerns, Wang Kang said that in the future, the national botanical garden in Beijing will contain plants from the northeast, northwest and the North China Plain with a similar latitude and climate to Beijing. “Plants that can’t be cultivated in open beds will be placed in greenhouses or experimental stations in suburban Beijing,” Wang said. 　

Xu, however, said that greenhouses should only be a supplementary measure to open beds as the primary place for ex-situ conservation and popular science display rather than being key to biodiversity conservation. A botanist told NewsChina under condition of anonymity that the national botanical garden in Beijing should concentrate on cultivating plants from northern China, and he cautioned that building large-scale greenhouses would have a high price tag. 　

Most botanical gardens in China are relatively small and urban based, which restricts ex-situ conservation. According to Xu, statistics from over 120 botanical gardens collected in 2008 show that small botanical gardens of less than 40 hectares accounted for 40 percent of the total, and botanical gardens of over 100 hectares accounted for about one-third. “Those small urban gardens don’t have to get involved in biodiversity conservation, they’re mainly for popular science display,” Xu said. 

A view of Shanghai Chenshan Botanical Garden, March 24, 2012

Chenshan Botanical Garden, Shanghai, October 6, 2021


Failure to Bloom 
In Xu Zaifu’s view, ex-situ conservation of plants requires basic conditions for climate (similarity of light, temperature and water humidity), habitat (similarity of topography, landform and soil conditions) and similar plant communities formed by flora and fauna and microorganisms. An adverse example, Xu said, was the cultivation of Podocarpus imbricatus, belonging to a family of coniferous trees and shrubs, and Pterospermum yunnanense, a type of flowering plant found only in China. These two species were transplanted from mountainous areas around 1,200 meters above sea level to 600 meters above sea level in Xishuangbanna Botanical Garden. Due to the significant change in climate conditions, the two species have not adapted well, and have not blossomed or borne fruit. Xu admitted that about onethird of the species under ex-situ conservation programs in domestic botanical gardens have died. 　

Liu Huajie pointed out in his recent article that despite the continued enthusiasm among academics, ex-situ conservation is unsuitable for most species. However, ex-situ conservation projects attract financial support and bring academic achievements for researchers. “A very limited number of plant species can be studied under specific conditions for temporary conservation, but it is not a long-term solution for the survival of the species or a universal protection measure,” Liu wrote. The effectiveness of ex-situ conservation needs long-term observation and study. Liu cautioned that the survival of plants under ex-situ conservation programs does not mean that the species has been protected effectively. “As we know, plants moved to botanical gardens and experimental fields normally have poor genetic diversity,” Liu added. 　

Compared to ex-situ conservation, near-site conservation is far more effective. This refers to the establishment of protection bases near where the plant naturally grows. 　

According to Xu’s research, growth adaptability and average annual growth of the same plant species in near-site conservation are in most cases much better than ex-situ conservation. The cost is also much lower. This is why botanical gardens should be as close to nature as possible, Xu said. 　

Sun Weibang said it is important to consider the purpose of collecting and conserving species when forming a strategy. “Whether it is used for scientific research, species conservation, science education, resource utilization or ensuring the safety of regional and national strategic plant resources, many botanical gardens in China seem to have not yet seriously thought about these issues.” 　

The National Forestry and Grassland Administration has taken the lead in planning the national botanical garden system and scouting locations, NewsChina learned. An official from the forestry administration told the Xinhua News Agency in early January that it is looking to speed up the process. 　

“The establishment of the national botanical garden in Beijing is an important part of the construction of the national botanical garden system,” the official said. “In the foreseeable future, national botanical gardens will be built in Guangzhou and other places, and we will gradually attain the goal that over 85 percent of wild native plants and all key national protected wild plant species will be protected locally.”　

Chenshan in Shanghai is waiting to hear if it will be the next national garden to gain official approval after Beijing. 　

According to Zhang Zhe, Chenshan Botanical Garden is continuing to innovate. It will build a top vegetation community conservation base for plants from typical low-altitude topography in East China. It will also develop an Asian plant information and data center. 　

“Based on the existing 18,000 species of plants, we will continue to increase the collection of plant species and aim to cultivate over 22,000 plant species by 2025 in our garden,” Zhang said. 

“We will improve the quality of the herbarium, seed database and DNA database, and become a national strategic resource plant reserve,” she said.
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