Ecology and population structure of a terrestrial mycoheterotrophic orchid, Aphyllorchis montana Rchb.f. (Orchidaceae) in Soppinabetta forests of the Western Ghats, India

Palatty Allesh Sinu,Kruthik Chandrashekara,Neethu Sinu

doi:10.11609/jott.o2743.2915-9

Abstract

While conducting a survey in the Western Ghats, we recently came across several populations of a mycohetertrophic orchid species, Aphyllorchis montana Rchb.f. during our ongoing ecological research in Soppinabetta forests (SBF) of Chikmagalur District in the central Western Ghats. The paper provides the details on the population structure and ecology of the species in SBFs of Sringeri. Fourteen different SBFs were surveyed to record the orchid shoots and clumps during the monsoon months from June-October in 2007 and 2008. Orchid clumps were located in five SBFs that were separated by a distance of 6 and 20 km from each other. Orchid clumps were located in the SBFs having either one of the three dipterocarp plant species, Hopea ponga (Dennst.) Mabb., Hopea parviflora Bedd. and Vateria indica L., as a dominant canopy tree. The local-scale leaf litter study showed that the leaf litter composition in the near vicinity of orchid clumps was clearly dominated by either of the above-mentioned species. This indicates that the associated host mycorrhizal fungi may be specific to the dipterocarpacean tree species. The possible reasons for the data deficient status of the species are discussed.

Highlights

The Western Ghats is a mega-biodiversity hotspot in India, and one among the 34 global Biodiversity Hotspots (Mittermeier et al 2004)
Terrestrial orchids are in need of species-specific fungi for seed germination and growth (Warcup 1973; Clements et al 1986); the relationship is obligate in mycoheterotrophic orchids (McCormick et al 2004)
As the vegetative growth of the terrestrial mycoheterotrophic orchid is absolutely an underground mechanism, it is a challenge to locate them in vegetative conditions (Rasmussen & Whigham 1998)

Summary

Introduction

The Western Ghats is a mega-biodiversity hotspot in India, and one among the 34 global Biodiversity Hotspots (Mittermeier et al 2004). The 1,60,000km hill stretch inhabits at least 1,500 endemic plant species that includes many rare, endangered and threatened plants (Ahamedullah & Nayar 1986). During our ongoing research in an unprotected, farmer-managed Soppinabetta forest (Sinu et al 2011, 2012) of Western Ghats, we came across several populations of a datadeficient mycoheterotrophic terrestrial orchid species, Date of publication (online): 26 August 2012 Date of publication (print): 26 August 2012 ISSN 0974-7907 (online) | 0974-7893 (print)

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Conclusion