Species diversity and abundance patterns of epiphytic orchids in Aralam Wildlife Sanctuary in Kerala, India

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Jis Sebastian
Durairaj Kathiresan
Giby Kuriakose


Species diversity and abundance patterns of epiphytic orchids were studied in Aralam Wildlife Sanctuary, in the Western Ghats of northern Kerala. Habitats sampled were wet evergreen (EVEG), montane wet evergreen (MEVG), moist deciduous (MDEC), and semi evergreen (SEVG), on a gradient of altitude from 60 to 1,589 m. Selective tree scanning on linear line transects was deployed (n= 40) across spatial units. A total of 39 orchid species were recorded. Rarefied species richness was maximum in the EVEG (20) habitat. Best suited rank abundance models were analysed for epiphytic orchids in each habitat and checked for significant differences. Bootstrap and Jackknife-1 estimators and species accumulation curves suggested higher species richness than observed, therefore more effort in sampling was needed in order to record all epiphytic orchids of the area. The difference in species richness between habitat types was not statistically significant (ANOVA). 38% of recorded epiphytic orchid species were endemic.

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Abraham, S. & P.S. Easa (1999). Additions to the amphibian fauna of Aralam Wildlife Sanctuary. Cobra 38: 12–13.

Abraham, A. & P. Vatsala (1981). Introduction to Orchids with Illustrations and Descriptions of 150 South Indian Orchids. Tropical Botanical Garden and Research Institute, Trivandrum, India, 533pp.

Annaselvam, J. & N. Parthasarathy (2001). Diversity and distribution of vascular epiphytes in a tropical evergreen forest at Varagalaiar, Western Ghats, India. Biodiversity and Conservation 10(3): 317–329. https://doi.org/10.1023/A:1016670621331

Benzing, D.H. (1990). Vascular Epiphytes General biology and related Biota. Cambridge University Press, Cambridge, United Kingdom, 354pp.

Benzing, D.H. (2004). Vascular epiphytes, pp. 175–211. In: Lowman, M.D. & H.B. Rinker (eds.). Forest Canopies. Elsevier Academic Press, San Diego, California, USA, 501pp.

Champion, H.G. & S.K. Seth (1968). A Revised Survey of the Forest Types of India. Natraj Publishers, Dehradun, India, 404pp.

Dantas, K.J., N. Sasidharan & K.V. Binu (2016). Additions to the angiosperms of the flora of Kannur district, Kerala, India from Aralam Wildlife Sanctuary. Annals of Plant Sciences 5(7): 1381–1388. https://doi.org/10.21746/aps.2016.07.003

Huang, H.W. (2011). Plant diversity and conservation in China: planning a strategic bio resource for a sustainable future. Botanical Journal of the Linnaean Society 166(3): 282–300. https://doi.org/10.1111/j.1095-8339.2011.01157.x

Jacquemyn, H., O. Honnay & T. Pailler (2007). Range size variation, nestedness and species turnover of orchid species along an altitudinal gradient on Reunion Island: Implications for conservation. Biological Conservation 136: 388–397. https://doi.org/10.1016/j.biocon.2006.12.008

Jalal, J.S. & G.S. Rawat (2009). Habitat studies for conservation of medicinal orchids of Uttarakhand, Western Himalaya. African Journal of Plant Science 3(9): 200–204.

Jalal, J.S. & J. Jayanthi (2012). Endemic orchids of peninsular India: a review. Journal of Threatened Taxa 4(15): 3415–3425. https://doi.org/10.11609/JoTT.o3091.3415-25

Jalal, J.S. (2012). Status, threats and conservation strategies for orchids of the western Himalaya, India. Journal of Threatened Taxa 4(15): 3401–3409. https://doi.org/10.11609/JoTT.o3062.3401-9

Jayalakshmi, P.S. (2016). Are the existing publications enough to study the endemic orchids of the Western Ghats?: A case study by using three major orchid publications from Kerala. MSc Thesis submitted to MG University, Kottayam, Kerala, 40pp.

Joseph, J. (1982). Orchids of Nilgiris. Records of the Botanical Survey of India, Howrah, Calcutta, 144pp.

KFD (2009). Aralam Wildlife Sanctuary Lifeline of Kannur. Kerala Forests and Wildlife Department. On the Silver Jubilee of Aralam Wildlife Sanctuary, Kannur, 73pp.

Kumar, C.S. (1999). Orchids of Silent Valley, pp. 191–216. In: Manoharan, T.M., S.D. Biju, T.S. Nayar & P.S. Easa (eds.). Silent Valley Whispers of Reason. Kerala Forest Department, Thiruvananthapuram, Kerala, 456pp.

Kumar, C.S. & K.S. Manilal (1994). A Catalogue of Indian Orchids. Bishen Singh Mahendra Pal Singh, Dehradun, India, 162pp.

Kumar, C.S. & K.S. Manilal (2004). Orchids of Kerala, India, pp. 155–252. In: Manilal, K.S. & C.S. Kumar (eds.). Orchid Memories: A Tribute to Gunnar Seidenfaden. Mentor Books & IAAT, Calicut, Kerala, 265pp.

Kumar, P., Rawat G.S. & H.P. Wood (2011). Diversity and ecology of Dendrobiums (Orchidaceae) in Chotanagpur Plateau, India. Taiwania 56(1): 23–36. https://doi.org/10.6165/tai.2011.56(1).23

Kumar, S., B.V. Shetty, D. Bennett & S. Molur (2000). Report of the Conservation Assessment and Management Plan Workshop on Endemic Orchids of the Western Ghats. Zoo Outreach Organisation & CBSG South Asia, Coimbatore, India, 150pp.

Manju, C.N., Rajesh, K.P. & P.V. Madhusoodanan (2009). Contribution to the bryophyte flora of India: the Aralam Wildlife Sanctuary in the Western Ghats. Archive for Bryology 42: 1–12.

Menon, A.R.R. (1999). Vegetation mapping and analysis of Aralam Wildlife Sanctuary using remote sensing techniques. KFRI Research Report 168,Kerala Forest Research Institute, Peechi, Kerala, 20pp.

Nadkarni, N.M. (1994). Diversity of species and interactions in the upper tree canopy of forest ecosystems. American Zoologist 34(1): 70–78.

Nair, V.P. (2001). Butterflies attracted to light at Aralam Wildlife Sanctuary, Kerala. Zoos’ Print 16(12): 670.

Nair, V.P. (2003). Congregations of Common Crow butterflies Euploea core (Cramer) at Aralam Wildlife Sanctuary, Kerala. Journal of the Bombay Natural History Society 100(2/3): 632–633.

Nair, S.C. (1991). The southern Western Ghats: a biodiversity conservation plan. Indian National Trust for Art and Cultural Heritage, In Monographic series: Studies in Ecology and sustainable development no.4, New Delhi, 92pp.

Padmawathe, R., Q. Qureshi & G.S. Rawat (2004). Effects of selective logging on vascular epiphyte diversity in a moist lowland forest of Eastern Himalaya, India. Biological Conservation 119(1): 81–92. https://doi.org/10.1016/j.biocon.2003.10.024

Pradhan, U.C. (1976). Indian Orchids: Guide to Identification and Culture Vol I. Premulaceae Books, Kalimpong, India, 188pp.

Pradhan, U.C. (1979). Indian Orchids: Guide to Identification and Culture Vol II. Premulaceae Books, Kalimpong, India, 189–747pp.

Radhakrishnan, C. (1996). Amphibians from Aralam Wildlife Sanctuary, Western Ghats, Kerala. Zoos’ Print 11(8): 5–6.

Rajesh, K.P. & P. Vijisha (2016). Pteridophyte flora of Aralam Wildlife Sanctuary, Kerala-A preliminary analysis. Cryptogam Biodiversity and Assessment 1(1): 71–74. https://doi.org/0.21756/cba.v1i1.11020

Ramesh, B.R. (2001). Patterns of Vegetation, Biodiversity and Endemism in the Western Ghats. In Y. Gunnell & B. Radhakrishna, Sahyadri-The great escarpment of the Indian Subcontinent. Kolkata: Geological Survey of India, 1053pp.

Richards, P.W., R.P.D. Walsh, I.C. Baillie & P. Greig-Smith (1996). The Tropical Rainforest: An Ecological Study. Cambridge University Press, Cambridge, UK, 575pp.

Sebastian, J., S.R. Rathinavel, P.S. Jayalakshmi & G. Kuriakose (2017). An Experimental Approach to Study the Distribution of Endemic Orchids In The Southern Western Ghats, pp. 217–243. In: Proceedings of Ecology 2017 International Symposium, Turkey.

Sinu, P.A., G. Kuriakose & K. Chandrashekara (2011). Epiphytic orchid diversity in farmer managed Soppinabetta forests of the Western Ghats: implications for conservation. Current Science 101(10): 1337–1346.

Sreekumar, P.G. & M. Balakrishnan (2001). Habitat and altitude preferences of butterflies in Aralam Wildlife Sanctuary, Kerala. Tropical Ecology 42(2): 277–281.

Webb, L.J. (1959). A Physiognomic classification of Australian rainforests. Journal of Ecology 47(3): 551–570.

Wolf, J.H.D., S.R. Gradstein & N.M. Nadkarni (2009). A protocol for sampling vascular epiphyte richness and abundance. Journal of Tropical Ecology 25: 107–121. https://doi.org/10.1017/S0266467408005786