Discovery of many new plant species in caves in Northern Vietnam
Assoc. Prof. Dr. Do Van Truong and experts conduct a cave survey in Thanh Hoa
Study of plant diversity in cave systems
Around the world, research on plant diversity in cave systems has been conducted since the 18th century in the Azores, South America or Europe. However, up to now, the understanding of cave biodiversity in general and cave flora in particular is still limited. The study of plant diversity in cave systems was initially of interest in some countries in tropical Asia (Thailand, China, Malaysia).
In Vietnam, cave systems contain many unique biological values. This is reflected in recent discoveries and descriptions of several species of animals that are new to science from caves in Vietnam. In the process of studying plant diversity in the limestone mountains, scientists have discovered and described two new and endemic plant species of the Elephant Ear family in caves in the Northwest mountains (Thanh Hoa and Hoa Binh). Thus, the cave system always has the potential to discover many rare and valuable species of organisms, which is the basis for research and conservation of biodiversity associated with socio-economic development. Initially, there were investigation and research programs on the diversity of one or several plant groups in the cave system in Vietnam. However, there has not been a complete, detailed and systematic study of the diversity of flora in cave systems in Vietnam in general and in the North in particular.
Map of the location of the caves surveyed in Northern Vietnam
Recently, eco-tourism and spiritual tourism activities in our country have attracted the attention of domestic and foreign tourists. Therefore, many cave systems in the North such as: Kho Muong Cave (Thanh Hoa), Thien Cung Cave (Ha Long, Quang Ninh), Huong Tich Cave (Hanoi), Quan Y Cave (Hai Phong). renovated to meet the needs of visitors. In addition to the pressure of tourism activities, the renovation process has been changing, even losing the habitat of some plant species in the cave, leading to the risk of extinction. Moreover, most of the information provided to visitors is information about landscape, geology, geomorphological values, lack of information about outstanding biodiversity values in caves. From the above fact, researchers from the Vietnam Museum of Nature have carried out the task of "Investigation and assessment of cave plant diversity in Northern Vietnam" (code: UQDTCB.06/22-23) in order to investigate, collect and determine plant species composition, evaluate biological characteristics, ecology, current conservation status and potential use value of cave plant species in Northern Vietnam.
Investigation and new discoveries
Through the investigation, scientists have collected 934 plant specimens of 539 specimen numbers in 33 caves in 08 provinces of Northern Vietnam (Ha Giang, Tuyen Quang, Cao Bang, Lang Son, Hoa Binh, Son La, Ninh Binh, Thanh Hoa). In particular, the average ratio of sample numbers/survey points in the Northeast and North Central provinces (Ha Giang, Tuyen Quang, Cao Bang, Lang Son, Thanh Hoa) has a much higher average ratio of sample numbers/survey points than in the Northwest provinces (Hoa Binh, Son La). In particular, 3 new species have been discovered and described for science (Bredia bullata H.Dai & Ying Li, Primulina crassifolia (Aver. & K.S.Nguyen) T.T.P.Anh, F. Wen & Mich.Möller, Microchiriata minor Z.B.Xin, T.V.Do & F.Wen) and 6 species added to the Vietnamese flora (Spiradiclis baishaiensis X.X.Chen & W.L.Shu, Euchresta tubulosa Dunn, Primulina jingxiensis (Yan Liu, W.B.Xu, H.S.Gao) W.B.Xu, K.F.Chung, Aristolochia austroyunnanensis S.M.Hwang, Henckelia nanxiensis Lei Cai & Z.L.Dao, Brandisia kwangsiensis H.L.Li).
Photos of three newly discovered plant species in the caves of Northern Vietnam (Bredia bullata - Primulina crassifolia - Microchiriata minor)
At the same time, the research team has identified 337 species belonging to 142 genera of 63 northern cave plant families. In which, the group of Ferns (Pteridophytes) includes 53 species (accounting for 15.73%), belonging to 22 genera (accounting for 15.49%) and 14 families (accounting for 22.22%); the group of angiosperms is more diverse with 284 species (accounting for 84.27%), belonging to 120 genera (accounting for 84.51%) of 49 families (accounting for 77.78%). Scientists established the spectrum of the life form of the flora in the Northern cave as follows: 59.35Ph + 29.38Ch + 5.04Hm + 5.34Cr + 0.9Th and identified 6 main phytogeographical factors of the Northern cave flora, of which the Asian tropical factor dominates (accounting for 21.7%). The results of the study show that the composition of plant species has changed markedly, from the mouth of the cave to the middle of the cave and the regeneration rate is low, gradually decreasing from the mouth of the cave to the low-light area, depending on the soil characteristics, topography and biological characteristics of the species.
In the study, the endangered status of 25 species of cave plants in the North has been identified as being on the IUCN Red List (2023), 4 species listed in the Red Book of Vietnam (2007), and 5 species listed in Decree 84/2021/ND-CP. Based on these results, scientists initially assessed the endangered status and conservation status of six recently described cave plant species. Through the investigation process, the team has identified 221 species of use value, of which 107 species are used for ornamental purposes (accounting for 31.75%), 82 species are used for medicine (accounting for 24.33%), 40 species are rare genetic resources (accounting for 11.87%), 15 species are used for wood (accounting for 4.45%), 14 species are used for food (accounting for 4.15%), 4 species used as fasteners (accounting for 1.19%). The research team has successfully built morphological and ecological databases for 337 plant species recorded in caves with basic data fields and built molecular data for 25 endemic cave plant species or newly discovered and described species in Vietnam based on nucleotide sequences of the nuclear gene region (ITS) and four chloroplast gene regions (trnK-matK-psbA, matK, trnL-trnF, rbcL).
Assoc. Prof. Dr. Do Van Truong shared: This is a necessary, urgent, highly practical task, providing a scientific basis to build a program for conservation and sustainable development of genetic resources of rare, endemic and valuable plant species, contributing to socio-economic development and restoration of forest ecosystems on limestone mountains in Vietnam. Within the framework of the mission, his team has published 06 scientific articles in international scientific journals in the SCI-E list and two articles in national journals and the task has been accepted and evaluated as Excellent by VAST. With the initial successes, scientists hope to continue investigating, researching, analyzing and classifying the samples that have been collected but there is not enough basis to classify the species. At the same time, it is necessary to continue to investigate the composition of cave plant species in the limestone mountain area in the central region of Vietnam. Regarding the research, screening and conservation of endemic and rare plant species of the limestone mountain area in general and the cave area in particular, it should be promoted because this is an important basis for exploiting and using unique genetic resources as a basis for cave landscape restoration for conservation and tourism development.
Translated by Phuong Ha
Link to Vietnamese version
