Launch of the National red List of Flora 2020 and Conservation Status of the Flora of Sri Lanka
Biodiversity is an asset of tremendous value both locally and globally. It is essential that this precious diversity of flora and fauna are preserved for future generations. The National Red List 2020 – Conservation Status of the Flora of Sri Lanka, calls upon our urgent attention to protect native plant species that are at risk of extinction. The Red List of plants in Sri Lanka is a rich compendium of information on the threats to Sri Lankan flora including indicators for potential actions that can be taken to reduce their risk of extinction.
The National Red List 2020 on Flora is prepared with coordination of the Biodiversity Secretariat of the Ministry of Environment and the main technical contribution of the National Herbarium of the Department of National Botanic Gardens including participation of an advisory group and a team of experts. The book includes national conservation status of plant species, especially flowering plants (Angiosperm), Ferns and Lycophytes (Pteridophyte) in Sri Lanka. In addition to those, checklists of Cryptogamic Flora (non- seed bearing plants: Algae, Lichens, Bryophytes and ferns) and Fungi of Sri Lanka also included in the 2020 Red List.
The National Herbarium of the Department of National Botanic Gardens is the main plant repository in Sri Lanka and it provided the basis for Red Listing Assessments on Angiosperm and Pteridophyte flora. This largest and scientifically treated data source on plant diversity of Sri Lanka houses over 180,000 presses and dried specimens collected throughout 200 years of the history of Botanical Studies in Sri Lanka. Botanic Gardens of Sri Lanka have played an eminent and decisive role in exploration and conservation of out native flora over 20 decades, this experience and information gained over the years make them essential institutions in compilation of the threatened status of local plants. Future plans of the Department also include updating equipping the National Herbarium of with new cutting-edge technology for a more effective role as well as establishing more areas for conservation of plants.
Threatened statuses of taxa were evaluated using standard guidelines published by the International Union for Conservation of Nature (IUCN). Data compilation, preparation of maps and assessments on Angiosperms were carried out by the Red Listing Team of the National Herbarium and presented to the expert group for final evaluation. During this effort, nomenclature for Angiosperm Plant families and species were also updated with taxonomic and nomenclatural expertise.
The National Red List 2020 evaluated a total number of 3,087 flowering plant species from 186 plant families. The present number of endemic flowering plant species is 863 (28% of total angiosperm flora). The last list compiled in 2012 contained a total of 3154 species, however during the current red listing process, it was observed that 131 species in the 2012 list needed to be removed since they were either naturalized exotics, misidentifications or those species previously considered as cosmopolitan which are now being recognized for their real natural distribution, which is outside Sri Lanka. The current red list includes 64 species that were not included in the 2012 National Red List. Among them, 2 10 are new species described since the publication of the National Red List 2012. The other 49 indigenous species were overlooked as they were not included in the Flora of Sri Lanka.
In the 2012 Red list five species were listed as extinct. Three of these species, Rinorea decora (Violaceae), Rinorea bengalensis and Crudia zeylanica (Fabaceae), were recollected during botanical surveys conducted after 2012. Therefore, only two species are now believed to be extinct. These extinct species are Strobilanthesc audata (Acanthaceae), and Blumea angustifolia (Asteraceae). Doona ovalifolia (Dipterocarpaceae) and Alphonsia hortensis (Annonaceae) were listed under the Extinct in the Wild Category (EW) in the 2012 Red List (MOE, 2012). Eugenia xanthocarpa (Myrtaceae) is added to the EW category in the current list. Alphonsea hortensisand Eugenia xanthocarpa are presently cultivated at Royal Botanic Gardens-Peradeniya.
Among the of 3,087 flowering plant species evaluated, 1,496 are threatened (critically endangered, endangered or vulnerable). This is about 48.4% of the total angiosperm flora in Sri Lanka. Distribution of threatened species shows that highest numbers of threatened species are found in wet zone districts such as Kandy, Ratnapura, Nuwara Eliya, Badulla, Matale, Galle and Kalutara. These districts also house the largest diversity of angiosperm species.
The National Red List of ferns and fern allies 2020 was compiled by team of scientists based on their expert knowledge and the specimen collection at the National Herbarium. That List contains 350 species including 42 endemics of which 207 species (59% of total species) were recorded as threatened.
Threats to the indigenous flora may range from direct causes such as habitat loss and environmental pollution to indirect factors such as unavailability of pollinators or dispersal agents. Whatever, the causal factors there may be, the proportion of threatened angiosperm plant species is exceedingly high. Therefore, findings of the Red List need to be paid more serious attention without delay by all concerned.
Provisional Checklists are presented for the first time in this Red Listing process, on the lower plant groups of taxa by the relevant expert groups as follows;
- Bryophytes: 345 species of liverworts, 07 species of hornworts, and 574 species of mosses were identified and listed.
- Marine Algae (Seaweeds): 139 species including 51 species of green algae, 23 species of brown algae and 65 species of red algae were identified and listed.
- Freshwater Algae: A list of freshwater algae including 90 taxa of planktonic green algae, 50 taxa of cyanobacteria, 25 taxa of diatoms, 13 species of euglenophytes, 41 taxa of diano-flagellates, prepared.
- Lichens: 876 species in 60 families have been identified and listed.
- Fungi: Section Fungi included two checklists of fungi in Sri Lanka. One of them provides 1,139 species of fungi associated with plants in Sri Lanka belonging to 422 genera and 183 families. The second checklist brings in 345 species of Agaric flora belonging to 96 genera known in Sri Lanka.