Nature Conservation Research. Заповедная наука 2020. 5(Suppl.1): 34–45 https://dx.doi.org/10.24189/ncr.2020.029 RESEARCH PRIORITIES AND FUTURE DIRECTIONS IN CONSERVATION OF WILD ORCHIDS IN SRI LANKA: A REVIEW J. Dananjaya Kottawa-Arachchi1,*, R. Samantha Gunasekara2 1Tea Research Institute of Sri Lanka, Sri Lanka 2Lanka Nature Conservationists, Sri Lanka *e-mail: [email protected], [email protected] Received: 24.03.2020. Revised: 22.05.2020. Accepted: 29.05.2020. Together with Western Ghats, Sri Lanka is a biodiversity hotspot amongst the 35 regions known worldwide. Considering the Sri Lankan orchids, 70.6% of the orchid species, including 84% of the endemics, are categorised as threatened. The distribution of the family Orchidaceae is mostly correlated with the distribution pattern of the main bioclimatic zones which is governed by the amount and intensity of rainfall and altitude. Habitat deterioration and degradation, clearing of vegetation, intentional forest fires and spread of invasive alien species are significant threats to native species. Illegally collection and exporting of indigenous species has been another alarming issue in the past decades. Protection of native species, increased public awareness, enforcement of legislation and introduction of new propagation techniques would certainly bring a beneficial effect to the native orchid flora. Conduct awareness programs, strengthen existing laws, and reviewing the legal framework related to the native orchid flora could be vital for future conservation. Apart from the identification of new species and their distribution, future research on understanding soil chemical and physical parameters of terrestrial habitats, plant association of terrestrial orchids, phenology patterns and interactions of pollinators, associations with mycorrhiza, effect of invasive alien species and impact of climate change are highlighted. Key words: awareness, biodiversity conservation, climate change, illegal exploitation, threatened species Introduction and divers forest types. The Western Ghats comprises The family Orchidaceae is one of the largest flow- the major portion of the Western Ghats and Sri Lan- ering plant families in the world, comprising about ka, one of 34 global biodiversity hotspots for conser- 25 000–30 000 species, and they account for approxi- vation and one of the two on the Indian subcontinent mately 8% of angiosperm species diversity (Chase et (Gunawardene et al., 2007; Myers et al., 2000). al., 2015). The distribution and abundance of orchids The aims of the present review are to summarise vary between continents and within regions, follow- the literature on studies of wild orchids including ing hotspot of species richness, except in the Polar publication information, location study, distribution Regions (Myers et al., 2000). However, their distribu- pattern, ecosystem/habitat characteristics, anthropo- tion is not uniform, but skewed markedly towards the genic effects and identifying the research gaps for tropics (Cribb et al., 2003). The highest epiphytic and promoting intense studies in future. terrestrial species diversity is recorded in the tropical areas, particularly in rainforests and associated eco- Material and Methods systems in the Andes of South America, on Madagas- Sri Lanka, with a total land area of 65 610 km2, is car, Sumatra and Borneo and in Indo-China. a tropical island situated in the Indian Ocean. Sri Lan- An enormous literature has emphasised that the ka’s rich and unique biodiversity forms the basis for future of orchid population is threatened and many the country’s natural heritage, and is a core feature of species will face the extinction from wild habitats due its cultural heritage and economic advancement. This to anthropogenic activities. Fragmentation of habi- high biodiversity seen in Sri Lanka can be attributed tats, indiscriminate collection, habitat destruction, due to a wide variety of climatic, topographic and soil intentional wild fires, pollinator decline will result in conditions on the island, resulted in a diverse array of the drastic loss of orchid populations (Fay, 2018). In aquatic and terrestrial habitats. Sri Lanka’s biodiver- Asia, due to a compound pressure on natural resourc- sity is significantly important both on a regional and es and the environment pollution associated with global scale as it has the highest species density for rapid urbanisation, industrialisation and economic flowering plants, amphibians, reptiles, and mammals development, a significant loss will be predicted for in the Asian region (MOE, 2012). The majority of the several wild species. endemic and threatened species are confined to the wet South Asia, including the Indian sub-continent, zone and especially to the montane ecosystem. The is considered as one of the mega biodiversity hotspot central highland complex of Sri Lanka is situated in (Myers et al., 2000). These zones consist of tropical, the south central part of the island and is considered as sub-tropical and temperate climate with lush green a super biodiversity hotspot (UNESCO, 2010). More 34 Nature Conservation Research. Заповедная наука 2020. 5(Suppl.1): 34–45 https://dx.doi.org/10.24189/ncr.2020.029 than 50% of the endemic vertebrates, 50% of the en- species, orchids form an interesting group. Fernando demic flowering plants and more than 34% of the en- & Ormerod (2008) have reviewed the contributions demic trees, shrubs, and herbs are reported from these to the discoveries of new species in the national or- diverse montane rainforests and associated grassland chid flora by the past botanists and taxonomists. The areas (Gunawardene et al., 2007; MOE, 2012). botanist Paul Hermann (1646–1695) was the first A thorough literature survey was conducted to botanist who made a collection of plants from Sri extract available information regarding distribution, Lanka and made an impressive collection of dried taxonomic status, threats, conservation and legal pro- plants and drawings. His collection included two or- tection of wild orchids in Sri Lanka. The following chids, Zeuxine strateumatica (L.) Schltr. and Peri- information was extracted from available sources, stylus cubitalis (L.) Kraenzl., the very first Sri Lank- both printed and digital platforms including printed an orchids made known to the world (Fernando & books, local and international journal articles, con- Ormerod, 2008). In addition, Konig (1728–1785) ference proceedings, case studies and reports. The made collections of Sri Lankan native orchids and journals were selected for this review on the basis of cited several specimens with their local names. their publications devoted to orchid related research. During the English colonial period, botanical Among the selected journals, Lankesteriana is fo- gardens were established in Sri Lanka and a large cusing exclusively on orchid systematics, ecology, number of herbarium collections were made by evolution, and physiology. Phytotaxa is a scientific various botanists. Alexander Moon, James Macrae, journal for publication on any aspect of systematic Colonel Walker and his wife collected many or- botany, new species, monographs, floras and revi- chid specimens from different parts of the country. sions. Recently discovered Sri Lankan orchids have The botanist George Gardener (1812–1849) and been published in Phytotaxa. Besides, research pa- the naturalist George H.K. Thwaites (1812–1882) pers and reviews published in leading international contributed to the botanical studies including na- journals such as Nature, Botanical Journal of the Lin- tive orchids immensely. The Handbook to the Flo- nean Society, Systematics and Biodiversity, Russian ra of Ceylon which is recognised as a model for a Journal of Ecology were referred to for the global tropical flora has been produced by Henry Trimen scenario in orchid conservation. Resently, Khapugin (1843–1896) and the volume containing Orchida- (2020) used a similar method for a systematic global ceae was completed by Joseph D. Hooker (1817– literature review on Orchidaceae taxa in Protected 1911). A revision of the entire flora was initiated in Areas. Further, abstracts and proceedings of local and 1968 and Martin A. Jayaweera (1912–1982) con- international conferenses have been used to include tributed to the revision of Orchidaceae. Fernando distribution and conservation data of Sri Lankan or- & Ormerod (2008) published an updated checklist chids in this review. using recent information of the orchids of Sri Lan- In addition to the personal experience of the sec- ka. They attempted to solve some nomenclatural ond author as Customs Officer, government acts were problems, species ambiguity, recent distribution referred to extract the legal coverage of native spe- records and find out current endemic species. Ari- cies. Personal communication with orchid specialists yarathne et al. (2017) recorded 78 wild orchids in- and data gathered during several field visits to various cluding 23 endemic species from 49 genera. They part of the country by the authors are also included are dispersed within and outside the conservation in this review to explain distribution patterns and an- areas including few unexplored/undocumented re- thropogenic effects. gions in the country. The National Red List 2012 of Sri Lanka was referred to for emphasising the threatened status of Present status of wild orchids native species. Recently published local and interna- The family Orchidaceae is among the larg- tional research articles have been referred