Endangered Orchids and Their Conservation in North East India 5
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Endangered Orchids and Their Conservation in North East India 5 L.C. De, A.N. Rao, and D.R. Singh Abstract Northeast India, a mega-diversity centre and a hotspot, comprises eight states, viz., Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim and Tripura. It occupies 7.7 % of India’s total geographi- cal area supporting 50 % of the flora (ca. 8000 species), of which 31.58 % (ca. 2526 species) are endemic. The region is rich in orchids, ferns, oaks (Quercus spp.), bamboos, rhododendrons (Rhododendron spp.), magnolias (Magnolia spp.), etc. Orchids, believed to have evolved in this region (Kumaria, Tandon, J North East Study IV: 57–71, 2007), form a very noticeable feature of the vegetation here. About 1331 species of orchids, belonging to 186 genera, were reported from India; Northeast India sustains the highest number with about 856 species. Amongst them, 34 species of orchids are identified amongst the threatened plants of India and as many as endemic to different states of this region. Out of the eight orchid habitat regions in India, the two most important areas, namely, the Eastern Himalayas and the Northeastern Region, fall within the political boundaries of Northeastern Region. Terrestrial orchids are located in humus-rich moist earth under tree shades in north-western India. Western Ghats harbour the small flowered orchids. Epiphytic orchids are common in Northeastern India which grows up to an elevation of 5000 MSL. The habitat loss, deterioration and fragmentation, introduction of exotic species, over-exploitation, environmental pollution, global warming, commercialisation of agriculture and forestry and jhum cultiva- tion are the major causes for the loss of diversity. India has strengthened L.C. De (*) • D.R. Singh ICAR-National Research Centre for Orchids, Pakyong 737106, Sikkim, India e-mail: [email protected] A.N. Rao Centre for Orchid Gene Conservation of Eastern Himalayan Region, Senapati District, Manipur, India # Springer Science+Business Media Singapore 2016 61 J. Purkayastha (ed.), Bioprospecting of Indigenous Bioresources of North-East India, DOI 10.1007/978-981-10-0620-3_5 62 L.C. De et al. on diversity conservation by implementing a series of act, rules, laws, regulations, agreements and developing network of protected areas. Keywords Diversity • Orchid • Species • Conservation • Northeast India 5.1 Introduction namely, the Eastern Himalayas and the North- eastern Himalayas, fall within the political Species diversity indicates the number of species boundaries of Northeastern Region. More than of plants and animals present in a region. one-fifth of the orchid species found in the region Maintaining a wide diversity of species in each are endemic, i.e. they are unique to the region ecosystem is necessary to preserve the web of life and are not found anywhere in the world. that sustains all living things. Biological diver- Indian terrestrials are distributed in humus- sity is also essential for preserving ecological rich moist earth under tree shades in north- processes, such as fixing and recycling of western India. Western Ghats harbour the small nutrients, soil formation, circulation and cleans- flowered orchids, whereas epiphytic orchids are ing of air and water, global life support (plants common in Northeastern India which grow up to absorb CO2, release O2), maintaining the water an elevation of 5000 MSL. Indian orchid species balance within ecosystems, watershed protec- with high ornamental values originated from this tion, maintaining stream and river flows through- region are Aerides multiflorum, Aerides out the year, erosion control and local flood odoratum, Arundina graminifolia, Arachnis, reduction (Chattaerjee et al. 2006). Bulbophyllum, Calanthe masuca, Coelogyne Northeast India, a mega-diversity centre and a elata, Coelogyne flavida, C. corymbosa, Cymbid- hotspot, comprises eight states, viz., Arunachal ium aloifolium, C. lowianum, C. devonianum, Pradesh, Assam, Manipur, Meghalaya, Mizoram, C. hookerianum, C. lancifolium, Dendrobium Nagaland, Sikkim and Tripura. It occupies 7.7 % aphyllum, D. nobile, D. chrysanthum, of India’s total geographical area supporting D. farmeri, D. densiflorum, D. moschatum, 50 % of the flora (ca. 8000 species), of which D. fimbriatum, D. jenkinsii, Paphiopedilum 31.58 % (ca. 2526 species) is endemic (Hegde, venustum, P. spicerianum, P. hirsutissimum, 2000). The region is rich in orchids, ferns, oaks P. insigne, Phaius wallichii, Pleione praecox, (Quercus spp.), bamboos, rhododendrons (Rho- Renanthera imschootiana, Rhynchostylis retusa, dodendron spp.), magnolias (Magnolia spp.), etc. Thunia alba, Vanda cristata, Vanda coerulea and Orchids, believed to have evolved in this Vanda coerulescens (Singh, 1990). region (Kumaria and Tandon, 2007), form a very noticeable feature of the vegetation here. About 1331 species of orchids, belonging to 5.2 Endemic Orchids 186 genera, were reported from India, and North- east India sustains the highest number of about Orchids are distributed from tropical to alpine 850 species. As many as 34 species of orchids zones in forest trees, secondary vegetations, from Northeast India are listed amongst the river banks, bamboo and palm thickets, forest threatened plants of India (Nayar and Sastry floor, grassy slopes and rocky areas and are con- 1987–1988, 1990; Ahmedullah et al. 1999), and sidered as an element in Farming System 85 species are endemic to this region (Das and Research (Chowdhery 1998, 2001). It is to be Deori 1983). Out of the eight orchid habitat noted that there are some orchid species which regions in India, the two most important areas, are endemic not only to this region but also to the 5 Endangered Orchids and Their Conservation in North East India 63 Renanthera imschootiana Cymbidium tigrinum Vanda stangeana Vanda coerulea Paphiopedilum hirsutissimum Paphiopedilum insigne Plate 5.1 Endemic orchids of NE India home states in which they are distributed in • Ascocentrum ampullaceum var. auranticum, Sikkim and Arunachal Pradesh Himalayas, the Epidendrum radicans and Vanda stangeana Naga and Manipur hills, the Lushai (Mizo) hills from Manipur and Khasi (Jaintia) hills (Nayar, 1996) (Plate 5.1). • Calanthe whiteana, Cymbidium whiteae and These are: Vanda pumila from Sikkim (Nayar, 1996) • Dendrobium spatella, Dendrobium parciflorum and Luisia macrotis from Assam • Vanda coerulea and Dendrobium palpebrae 5.3 Orchid Diversity in Eastern from Arunachal Pradesh Himalayas and North Eastern • Renanthera imschootiana and Cymbidium India tigrinum from Nagaland • Anoectochilus crispus, Cymbidium eburneum, The region includes Darjeeling district of West Habenaria khasiana, Liparis deliculata, Bengal and other Northeastern states, Paphiopedilum venustum, Taeniophyllum i.e. Arunachal Pradesh, Assam, Manipur, khasianum and Tainia khasiana from Meghalaya, Mizoram, Nagaland, Sikkim and Meghalaya Tripura. This region is relatively warmer with • Renanthera imschootiana from Tripura high humidity and heavier precipitation and • Dendrobium palpebrae from Mizoram endowed with 870 species in 159 genera 64 L.C. De et al. Table 5.1 Orchid distribution under forest cover in Northeast India (Hajra and De 2010; Hegde 1997, 2000, 2001, 2005, 2007, 2012; Manilal and Sathish Kumar 2004; Kataki et al. 1984; Chowdhery 2009; Pradhan 1976, 1979) State Area Dense forest Orchid 000 km2 % forest cover Genera Species Arunachal Pradesh 83,743 54,542 65.13 130 622 Assam 78,438 15,842 20.19 74 290 Manipur 22,327 5309 23.77 67 215 Meghalaya 22,429 3305 14.73 98 389 Mizoram 21,081 4279 20.29 74 234 Nagaland 16,579 3531 21.29 64 246 Sikkim 7096 2403 38.86 132 543 Tripura 10,488 1825 17.40 37 57 Table 5.2 Some monotypic orchid genera of Northeast (Table 5.1). Amongst the other states of India this region, Assam accounts for 290, Nagaland Name of orchid genera for 246, Mizoram for 234, Manipur for Anthogonium Wall. Ex Lindl Arundina Bl 215 and Tripura for 57 species (Hajra and De, Acrochaene Lindl Bulleyia Schltr 2010). Cremastra Lindl Cleisocentron The Northeast India has highest flora of Bruhl monotypic orchid genera (Table 5.2) (Tandon Dickasonia L.O. Williams Diglyphosa Bl et al. 2007). Eriodes Rolfe Herpysma Lindl Jejosephia A.N. Rao & Mani Mischobulbum Northeast India is reported to harbour a schltr large number of valuable threatened orchids Myrmechis (Lindl.) Bl Neogyne reichb.f (Table 5.3). Ornithochilus (Lindl.) Wall. Ex Risleya King & Benth Pantl Renanthera Lour Tipularia Nutt 5.4 Orchid Diversity in Arunachal Pradesh Table 5.3 Some threatened orchids of Northeast India (Tandon et al. 2007) There are more than 600 species of orchids in Name of orchid species Arunachal Pradesh alone – the highest number Acanthephippium Bulleyia yunnanensis in any state (of these, 377 are epiphytes, sylhetense 160 autophytic terrestrials, and about Cymbidium eburneum Cym. devonianum 20 saprophytes). Major epiphytic genera include Cym. tigrinum Dendrobium chrysotoxum Den. densiflorum Den. falconeri Aerides, Arachnis, Bulbophyllum, Coelogyne, Eria fragrans Paphiopedilum Dendrobium, Cymbidium, Eria, Cleisostoma, fairrieanum Rhynchostylis, Vanda, etc. Most of the epiphytic P. insigne P. venustum orchids are ornamentals (Hegde 1984, 2000, P. villosum Renanthera imschootiana 2001, 2005). In the tropical valleys of Arunachal Vanda coerulea Vanilla pilifera Pradesh, one can find cascades of colourful Vanda pumila Epigeneium rotundatum flower spikes of Rhynchostylis retusa, Aerides odorata, A. williamsii, A. rosea, Cymbidium pen- constituting 72.8 % of the total