Chasmophytic grasses of Velliangiri Hills in the southern Western Ghats of Tamil Nadu, India
Binu Thomas 1, A. Rajendran 2, K. Althaf Ahamed Kabeer 3 & R. Sivalingam 4
1,2,4 Department of Botany, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu 641046, India
3 Botanical Survey of India, Southern Circle, Coimbatore, Tamil Nadu 641003, India
Email: 1 email@example.com, 2 firstname.lastname@example.org,
3 email@example.com, 4 firstname.lastname@example.org (corresponding author)
Rock crevices play a key role in forming a major habitat for many plants, and host rich biodiversity within a small area. The rocky habitat provides extremely harsh physical environment for plants that leads to the development of specialized plant communities with endemic and habitat specific species. The microhabitat like rock crevices possess diverse forms of plants, which are mainly seasonal herbs. These habitats differ from each other due to changes in geographical terrain and soil cover (Porembski 2000).
Chasmophytes are plants rooted in clefts of rocks that are filled with detritus. In these clefts particles of earth conveyed by wind and water accumulate. The amount and rate of accumulation depend upon the width and situation of the clefts (Davis 1982). The soil thus constituted facilitates plants to establish and their dead fragments further add to the supply of the nutritive material in the clefts (Bashan et al. 2002). The chasmophytic vegetation inhabiting rock crevices and cliffs represent specific habitat with extreme ecological conditions such as extreme drought, temperature fluctuations, width of the cliffs, rate of accumulation, limited soil volume and scarce nutrients, nature of the rock types, rock hardness and sediment porosity and water holding capacity of the substratum (Nagy & Proctor 1997; Bashan et al. 2002, 2006).
The grass family occupies 23% of the land area of the world, playing a significant role in the life of human beings and animals, and has a paramount role as a food provider, accounting for more than 80% of the world’s calories (Kabeer & Nair 2009). A comprehensive account of the grasses of Tamil Nadu was published by Kabeer & Nair (2009) in their floristic studies. However, there has been no study of chasmophytic features of grasses as yet. A comprehensive study was carried out to assess the chasmophytic diversity of grasses from Velliangiri Hills of southern Western Ghats of Tamil Nadu (Fig. 1).
Study area and Methods: Velliangiri Hills are floristically rich and socio-religiously important range of southern Western Ghats situated 40km west of Coimbatore City, Tamil Nadu. The study area lies between 6040’–7010’E and 10055’–11010’N between 520–1840 m. A famous temple called ‘Velliangiri Aandavar’ temple also called “Thenkailayam” (South Kailas) is situated at the peak of the hills (1840m). The range of study area consists of seven hills with different altitudes and topography.
Correct nomenclature, habit, habitat, phenology and pattern of distribution available are given (Table 1). Plant specimens were identified with regional and local floras (Gamble & Fischer 1988; Mathew 1983; Chandrabose & Nair 1988; Henry et al. 1989; Kabeer & Nair 2009). The voucher specimens are deposited in the herbarium of Botany Department, Bharathiar University (BUH), Coimbatore, Tamil Nadu, India.
Results and Discussion: The data presented here are the outcome of a series of extensive and intensive studies conducted during September 2010–October 2011 had resulted in the documentation and collection of 30 species of wild chasmophytic grass taxa from Velliangiri Hills of southern Western Ghats of Tamil Nadu (Images 1–35).
The present study incorporated 30 species of chasmophytic grasses distributed in 26 genera (Table 1). Among these genera Eragrostis is the dominant genus with four species, namely, aspera, tenella, nigra and uniloides. Some of the notable chasmophytic grasses are used by the local tribe ‘Malasars’. The stalks of Apluda mutica are used for making hats. Cymbopogon flexuosus is used to extract the lemon grass oil for medicinal purposes. Ash of Pogonatherum crinitum are used for skin problems. The spikelets of Setaria palmifolia and Melinus repens are highly attractive and used ornamentally. Most of the grasses are used as fodder.
Some of the threats like heavy influence of pilgrims, recreational pressures, collection of fire wood, lack of suitable management and other construction activities adversely affect the existing ecosystem. It is suggested that the chasmophytic vegetation needs to be protected through sustainable utilization.
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