Rescuing Christensenia aesculifolia (Marattiaceae), a plant species with an extremely small population in China
L EI C AI,GUILIANG Z HANG,JIANYING X IANG,ZHILING D AO and W EIBANG S UN
Abstract The rare and threatened fern Christensenia aescu- Diniz et al., ). In C. aesculifolia was categorized na- lifolia of South-east Asia is listed in China as a second- tionally as Critically Endangered on the China Biodiversity ranked plant for national protection and is also categorized Red List (on the basis of criteria Blab(i,ii) + a(i,ii), Ca(i)), as one of plant species with extremely small populations and in it was included in the Threatened Species List by the Yunnan provincial government. Field investigations of China’s Higher Plants because of the extremely low num- during – failed to relocate one previously known bers of individuals in China (Qin et al., ). population, and revealed that the single known extant popu- Christensenia aesculifolia has the largest synangia on the lation of C. aesculifolia contains only individual plants. back of the leaves of any fern; this is one of its distinguishing The most urgent conservation requirement for this species features. It does not resemble a typical fern, and without is to conserve the threatened habitat of the remnant popu- sporangia appears similar to Typhonium trilobatum (L.) lation. Further field surveys and research are also required Schott and is often mistaken for a species of Araceae. for an improved understanding of the species’ status. Surveys in October (for days by six people), August ( days by five people), September Keywords China, Christensenia aesculifolia, conservation, ( days by four people) and April and November Marattiaceae, plant species with extremely small popula- ( days by four people) led by LC in Lvchun, Jinping and tions, population status, rescue Hekou Counties, Honghe Prefecture, and in November ( days by six people) and August ( days by n China there is a particular focus on the conservation of seven people) led by ZD in Malipo and Maguan Counties, plant species categorized as having extremely small Wenshan Prefecture, found only one locality, with indi- I populations. One of these is the fern Christensenia aesculifolia vidual plants, in an area of c. m in a karst rainforest in (Bl.) Maxon (Marattiaceae) (with the synonyms Aspidium aes- Hekou County (Fig. ). Christensenia aesculifolia was for- culifolium, Christensenia assamica, Christensenia lobbiana, merly also known from Jinping County but this population Kaulfussia aesculifolia, Kaulfussia assamica, Kaulfussia seems to have disappeared as a result of the destruction of its korthalsii and Kaulfussia lobbiana), which is found through- habitat; it was last recorded there in the s. out limestone areas of South-east Asia (Rolleri, ;He& In general deforestation is the main cause of the destruc- Christenhusz, ). Although this species is widely distribu- tion of natural vegetation in Yunnan, with trees felled to ted, the number of populations is low. Christensenia aesculi- support social and economic development and for the folia has not yet been assessed for the IUCN Red List but it planting of banana and rubber trees. The area in which was listed as a provincial second-ranked protected wild plant the extant population of C. aesculifolia occurs in Hekou is in Yunnan in , and as a national second-ranked protected being used by farmers for planting Amomum villosum wild plant in China in .InMarch it was identified as Lour. However, the population is in a valley, at the edge of one of plant species with extremely small populations in an A. villosum field, and thus has not been completely re- Yunnan because of its small remaining population, restricted moved by farmers (Plate ), who clean away weeds (includ- habitat, a high degree of disturbance from people, and a high ing C. aesculifolia) around the A. villosum field. In a similar risk of extinction (Ma et al., ;Sun,;Wangetal.,; manner, habitat loss and fragmentation are the main threats to other plant species in China that have extremely small po- pulations (Ren et al., , ; Chen et al., ; Li et al., LEI CAI*, ZHILING DAO and WEIBANG SUN (Corresponding author) Kunming ; Volis, ). Botanical Garden, Kunming Institute of Botany, Chinese Academy of Although the remnant population of C. aesculifolia is Sciences; Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming, Yunnan 650201, China within Daweishan National Nature Reserve, the effective- E-mail [email protected] ness of protection is low and a small dedicated protected GUILIANG ZHANG Hekou Forestry Bureau, Yunnan, China area is required to protect the few remaining individuals
JIANYING XIANG Yunnan Academy of Biodiversity, Kunming, Yunnan, China and their habitat, with logging and setting of fires prohibited. *Also at: University of Chinese Academy of Sciences, Beijing, China We have worked with the local government and farmers, who have now halted farming activities in this area, and we are also Received August . Revision requested February . Accepted February . First published online August . carrying out regular patrols to protect the remaining plants.
Oryx, 2019, 53(3), 436–438 © 2018 Fauna & Flora International doi:10.1017/S003060531800039X Downloaded from https://www.cambridge.org/core. IP address: 170.106.40.139, on 27 Sep 2021 at 13:55:13, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S003060531800039X Rescuing Christensenia aesculifolia 437
FIG. 1 Location of the extant population in Hekou County and of the lost population in Jingping County.
Additionally, we plan to erect appropriate advisory signs and a from plants already cut down by farmers. In November plaque explaining conservation goals for C. aesculifolia,con- we collected mature spores and several young shoots struct fencing, and hire specialized staff. from living wild plants for breeding and cultivation at In October and November we collected spores Kunming Botanical Garden; germination trials are ongoing. of C. aesculifolia for preliminary germination experiments, As of November the rhizomes of the plants located but these failed, perhaps because the spores were collected in the wild are all growing.
PLATE 1 Christensenia aesculifolia, showing (a) its natural habitat, (b) habitat destruction, (c) bud, (d) destruction of individual plants, and (e) and (f) plants cut down by farmers, showing spores.
Oryx, 2019, 53(3), 436–438 © 2018 Fauna & Flora International doi:10.1017/S003060531800039X Downloaded from https://www.cambridge.org/core. IP address: 170.106.40.139, on 27 Sep 2021 at 13:55:13, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S003060531800039X 438 L. Cai et al.
An ex situ collection of C. aesculifolia at Kunming References Botanical Garden was introduced from Hekou County in , but is not thriving. There are two other small popula- CHEN, Y.K., YANG, X.B., YANG, Q., LI, D.H., LONG, W.X. & LUO, W.Q. () Factors affecting the distribution pattern of wild plants tions in cultivation in China, both of which were originally with extremely small populations in Hainan Island, China. PLoS obtained from the population at Hekou County: a small ONE, ,e. population in Xishuangbanna Tropical Botanical Garden DINIZ, M.F., GONCALVES,T.V.&BRITO,D.() Last of the green: and two plants in Shenzhen Fairylake Botanical Garden. identifying priority sites to prevent plant extinctions in Brazil. Oryx, Public education, especially of local residents, is a crucial , –. element of any conservation strategy for plant species with ex- HE, Z.R. & CHRISTENHUSZ, M.J.M. ( ) Marattiaceae. In Flora of China, Vol. (eds Z.Y. Wu & P.H. Raven), pp. –. Science tremely small populations. We have developed mechanisms for Press, Beijing, China, & Missouri Botanical Garden Press, providing public education about the importance of protecting St. Louis, USA. plant species with extremely small populations, both at LI, B., ZHANG, Z.Y. & ZHANG, D.X. () Conservation status of the Kunming Botanical Garden and among local communities in unique population of Wenchengia alternifolia, an enigmatic plant – the native range of several other such species: Bretschneidera endemic to Hainan Island, China. Oryx, , . MA, Y.P., CHEN, G., GRUMBINE, R.E., DAO, Z.L., SUN, W.B. & GUO, sinensis, Coptis quinquesecta, Cycas spp., Magnolia spp., H.J. () Conserving plant species with extremely small Paphiopedilum spp. and Paraisometrum mileense. populations (PSESP) in China. Biodiversity and Conservation, , As with other plant species with extremely small popula- –. tions, C. aesculifolia is rare in China and the population is in QIN, H.N., YANG, Y., DONG, S.Y., HE, Q., JIA, Y., ZHAO, L.N. et al. ’ urgent need of rescue. Despite the advances described here, ( ) Threatened species list of China s higher plants. Biodiversity Science, , –. further field surveys and research are required for an REN, H., JIAN, S., CHEN, Y., LIU, H., ZHANG, Q., LIU, N. et al. () ’ improved understanding of the species status. Protection Distribution, status, and conservation of Camellia changii Ye against human disturbance and in situ conservation are (Theaceae), a Critically Endangered plant endemic to southern currently the most urgent tasks. China. Oryx, , –. REN, H., ZHANG, Q.M., LU, H.F., LIU, X.H., GUO, Q.F., WANG,J. et al. () Wild plant species with extremely small populations Acknowledgements This work was supported by the Science & require conservation and reintroduction in China. Ambio, , Technology Basic Resources Investigation Program of China –. (2017FY100100), Yunnan Provincial Wildlife Conservation Projects ROLLERI,C.() Revision of the genus Christensenia. American Fern (201606). Journal, , –. SUN, W.B. () Conserving Plant Species with Extremely Small Populations (PSESP) in Yunnan: Practice & Exploration. Author contributions Writing: LC; revision and editing: JX, WS; Yunnan Science and Technology Press, Kunming, China. fieldwork: GZ, ZD, LC. [In Chinese]. VOLIS,S.() How to conserve threatened Chinese plant species Conflicts of interest None. with extremely small populations? Plant Diversity, , –. WANG, B., MA, Y.P., CHEN, G., LI, C.R., DAO, Z.L. & SUN, W.B. () Rescuing Magnolia sinica (Magnoliaceae), a Critically Endangered Ethical standards This research complied with the Oryx Code of species endemic to Yunnan, China. Oryx, , –. Conduct.
Oryx, 2019, 53(3), 436–438 © 2018 Fauna & Flora International doi:10.1017/S003060531800039X Downloaded from https://www.cambridge.org/core. IP address: 170.106.40.139, on 27 Sep 2021 at 13:55:13, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S003060531800039X