The Vulnerable and Endangered Plants of Xishuang- banna Prefecture, Yunnan Province, China Zou Shou-qing Efforts are now being taken to preserve endangered species in the rich tropical flora of China’s "Kingdom of Plants and Animals" Xishuangbanna Prefecture is a tropical area of broadleaf forest-occurs in Xishuangbanna. China situated in southernmost Yunnan Coniferous forest develops above 1,200 me- Province, on the border with Laos and Burma. ters. In addition, Xishuangbanna lies at the Lying between 21°00’ and 21°30’ North Lati- transitional zone between the floras of Ma- tude and 99°55’ and 101°15’ East Longitude, laya, Indo-Himalaya, and South China and the prefecture occupies 19,220 square kilo- therefore boasts a great number of plant spe- meters of territory. It attracts Chinese and cies. So far, about 4,000 species of vascular non-Chinese botanists alike and is known plants have been identified. This means that popularly as the "Kingdom of Plants and Xishuangbanna, an area occupying only 0.22 Animals." The Langchan River passes percent of China, supports about 12 percent through its middle. of the species in China’s flora. The species be- Xishuangbanna is very hilly, about 95 per- long to 1,471 genera in 264 families and in- cent of its terrain being hills and low, undu- clude 262 species of ferns in 94 genera and 47 lating mountains that reach 500 to 1,500 families, 25 species of gymnosperms in 12 meters in elevation. The highest peak is 2,400 genera and 9 families, and 3,700 species of meters in elevation. High mountains in the angiosperms in 1,365 genera and 208 families. north, including the Wuliang and Ailao The tropical features of Xishuangbanna’s Mountains, block the cold air from the north flora are quite distinct. Such tropical families and trap warm, humid air from the Indian as the Dipterocarpaceae, Myristicaceae, Ocean, creating a hot, humid, windless tropi- Tetramelaceae, Anonaceae, and Dilleni- cal climate. The mean annual temperature is aceae, and such genera as Ficus, Artocarpus, 18 C to 22 C, and, depending upon elevation Antiaris, Dysoxylum, and Aphanamixis are and topography, 1,000 millimeters to 2,200 represented. About 60 percent of the species millimeters of precipitation fall annually; as in Xishuangbanna’s flora also occur in Viet- a result, tropical forest and other tropical nam, Laos, Burma, and India. During the past vegetation flourish on hillsides and in val- two centuries, many species from the Indo- leys. A great diversity of vegetation types- chinese peninsula and other tropical regions including tropical rain forest, seasonal rain have been successfully introduced into forest, montane rain forest, and evergreen Xishuangbanna. Among them have been Cassia siamea, Mesua ferrea, Crinum asi- aticum, Cananga odorata, and Bixa orellana. Cycas pectinata Griffith, a rare and vulnerable species. There are many endemic species in a ornamental and its and It is spectacular plant, fruit Xishuangbanna’s flora, such as Manglietia stem are used in medicine by the Dai minority of China. Photographs by the author. wangii, Polyalthia cheliensis, Phc~bepuwen- 4 sis, and Horsfieldia tetratepala; a number of carpa, Ostodes katharinx, and Pyrularia relict species, such as Cycas pectinata, Podo- edulis, for example, are important sources of carpus wallichii, Magnolia henryi, and Slad- food oil or industrial oil. Ten species-Cala- enia celastrifolia; and many rare species, mus flagellum, Calamus palustris, Calamus such as Manglietia fordiana, Michelia hed- nambariensis, etc.-yield rattan. Many spe- yosperma, Paramichelia baillonii, and Pseu- cies are aromatic, tanning, or resin and gum duvaria indochinensis. According to data plants, among them Elsholtzia blanda, Cin- collected by Li Yanhui, 153 endemic species, namomum mollifolium, Phyllanthus em- 31 relict species, and 133 rare species grow in blica, and Sterculia villosa. Xishuangbanna; of them, 110 are endangered During the past 20 years, many forests in or vulnerable (see the list on pages 6 and 7). Xishuangbanna were ruined. More than Twenty-eight wild types of cultivated 13,000 hectares of forest were cut each year as plant species and their relatives occur in a result of shifting cultivation, conversion to Xishuangbanna’s flora, among them Oryza rubber plantations, and demands for timber minuta, Camellia sinensis var. assamica, and fuel by local people. Recently, the forest Coix lacryma-jobi, Citrus grandis, and cover of Xishuangbanna has declined sharply, Momordica subangulata. Some may prove to from about 60 percent to 33 percent. Many have significant value in genetic research and hillsides that once were covered with rain breeding. forests are now grassland of cogongrass and More than 1,000 species in Xishuang- low shrub. Along with the destruction of banna’s flora are economically important. tropical forests, obviously, many plant and About 500 of them are medicinal plants that animal species have been threatened. It is are used locally or in traditional Chinese estimated that one species is lost for every medicine; among these are Amomum villos- 700 hectares of tropical forest ruined. If this is um, Taraktogenos merrillana, Cissampelos so, then more than 800 species of plant have paraira var. hirsuta, and Homalomena been lost or are in danger of being lost. If occulta. Rauvolfia yunnanensis has become remedial measures are not taken today, many an important source of reserpine, and May- species with valuable properties will be lost. tenus hookeri is alleged to have anti-cancer This would be a big mistake, one that our properties. descendents would be unlikely to forgive. More than 100 species of tree in Xishuang- The first volume of the Plant Red Data banna’s flora grow fast or produce high-qual- Book for China, recently issued by the Acade- ity timbers, the best example being Dal- mia Sinica (the Chinese Academy of Science), bergia fusca var. enneandra, which has lists 389 endangered species of Chinese purple-black heartwood. Its wood is very plants. The Book gives their morphological hard, heavy, and tough and so is used as a features, distributions, and statuses and de- substitute for rosewood. The fast-growing scribes methods for their conservation. Fifty- species Anthocephalus chinensis is another four of the species it lists are native to Xi- example. It is the most productive timber tree shuangbanna. in tropical tree plantations. Toona ciliata, The Chinese government devotes more Paramichelia baillonii, Gmelina arborea, attention to nature conservation now than it Altingia excelsa, Chukrassia tabularia var. once did. For example, 310 nature reserves, velutina, and Dysoxylum binecea?folium are with a total area of 167,000 square kilome- all valuable hardwood timber trees that are ters, have been established throughout the used in industry and construction. country, and the funding of nature-conserva- Xishuangbanna’s flora contains more than tion programs has been increased. In Xi- 100 oil-bearing species. Horsfieldia tetra- shuangbanna Prefecture, some 600,000 hec- tepala, Jatropha cureas, Hodgsonia macro- tares of tropical forest survive. To protect re- maining ecosystems and species, 200,000 forest fires, stop hunting and timbering hectares of land (about one tenth the within nature reserves, and deal with crimi- prefecture’s area) have been set aside as re- nal cases of vandalism. serves, including the Mengyang, Mengla, The Yunnan Institute of Tropical Botany, Menglun, Menghai, and Dashujiao reserves, Academia Sinica-formerly the Botanical and a team of 150 forest guards has been Garden of Xishuangbanna-is located in the organized. The guards patrol forests, prevent prefecture. It is has become an active center Caryota urens Linnxus, the wine (or sago) palm, is an endangered species in China. The Dai minority use the tasty starch in the middle of the trunk for food. 6 for the study and conservation of tropical China or for that matter in the world, con- plants. More than 2,500 local and otherwise tains many rare, endemic, and economically tropical plant species, including dozens of valuable species. A veritable treasury for our endangered species, have been introduced well-being, it has suffered seriously in the and cultivated there. past. We must now work hard to prevent Xishuangbanna is a treasure house of natu- further losses to it. ral resources. Its flora, one of the richest in Vulnerable and endangered members of Xishuangbanna’s flora (The symbols indicate that a species is vulnerable ( * ) or endangered (~); species listed as endangered in the Plant Red Data Book for China are printed in boldface type. Relict species * Cinnamomum mollifolium H. W. Li * Alsophila spinulosa (Wallich ex Hooker) Litsea dilleni~folia P. Y. Bai 8z. P. H. Huang Tryon ~Neolitsea menglaensis Yang & P. H. Huang * Cycas pectinata Griffith * Horsfieldia pandurifolia Hu * Anchangiopteris henryi Christ & Giesenhagen i~Horsfieldia tetratepala C. Y. Wu * Cycas siamensis Miquel * Myristica yunnanensis Y. H. Li * Podocarpus imbricata Blume ~Anemone filisecta Wu & Wang ~Podocarpus wallichii Presl ~Capparis fohaiensis B. S. Sun ~Podocarpus fleuryi Hickel ~Xanthophyllum yunnanensis C. Y. Wu * Podocarpus nerrifolia Wight * Heliciopsis lobata (Merrill) Slaum var. micro- ~Cephalotaxus oliveri Masters carpa C. Y. Wu & T. Z. Hsu Magnolia henryi Dunn Heliciopsis terminalis (Kurz) Sleumer * Sladenia celastrifolia Kurz Homalium laoticum Gagn. var. glabretum C. * Cenocentrum tonkinense Gagnepain Y. Wu ~Borthwickia trifoliata W. W. Smith * Parashorea chinensis Wang Hsie * Silvianthus bracteata Hooker fils ~Pellacalyx yunnanensis Hu * Pittosporopsis kerrii Craib ~Camellia taheishangensis F. S. Zhang * Cephalostigma hookeri C. B. Clarke ~Garcinia lancilimba C. Y. Wu ex Y. H. Li * Campanumcea parviflora /Wallich) Bentham ~Garcinia xishuangbannaensis Y. H. Li ~Zippelia begonixfolia Blume ~Ochrocarpus yunnanensis H. L. Li ~Grewia falcata C. Y. Wu Endemic species ~Sloanea cheliensis Hu * Manglietia wangii Hu ~Pterospermum yunnanensis Hsue * Manglietia microgyna Liou ~1’terospermum mengluensis Hsuee * ~Magnolia delavayi Franchet var. albivillosa Ostodes kuangii Y. T. Chang Liou * Sauropus coriaceus C. Y. Wu ~Cyathocalyx yunnanensis Y. H. Li & P.