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.