Vegetation Composition and Woody Species Diversity at Chandoli National Park, Northern Western Ghats, India
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RESEARCH ARTICLES Vegetation composition and woody species diversity at Chandoli National Park, northern Western Ghats, India R. Kanade1,†, M. Tadwalkar2,†, C. Kushalappa3,† and A. Patwardhan1,2,†,* 1Research and Action in Natural Wealth Administration, 16, Swastishree Society, Ganesh Nagar, Pune 411 052, India 2Biodiversity Section, M.E.S. Abasaheb Garware College, Karve Road, Pune 411 004, India 3College of Forestry, Ponnampet, Coorg 571 216, India †Team Members, Western Ghats Bioresource Mapping Project of Department of Biotechnology, India Except for sporadic records that are available regarding Woody plant species diversity at Chandoli National 5,6 Park, an under-explored area from northern Western quantitative studies , forest studies conducted so far in Ghats, Maharashtra, was assessed in detail by esta- northern Western Ghats (NWGs) are largely based on blishing ten transects of 1000 m × 5 m each. All indi- qualitative descriptions (forest type, physiognomy, domi- 7,8 viduals with GBH ≥15 cm were enumerated. A total of nant species, etc.) and taxonomic explorations . On the 4200 stems were sampled which represented 107 spe- contrary, there are ample records of quantitative invento- cies belonging to 86 genera and 44 families. Shannon’s ries on floristics and ecological assessments of the vege- index value ranged from 2.0 to 3.2. We have identified tation in general and Protected Areas (PAs) in particular, a new subtype Memecylon–Syzygium–Olea of previ- that are available from southern Western Ghats (SWGs), ously defined Memecylon–Syzygium–Actinodaphne flo- e.g. Mudumalai Tiger Reserve9, Kalakad–Mundanthurai ristic series in the literature. Family importance value Tiger Reserve (KMTR)10,11 and Agastyamalai Region12. of pooled data showed that Melastomataceae was the The vegetation of NWGs remains understudied in general, most dominant family (50.32), followed by Myrtaceae which prevented ecologists from generating a holistic (32.39) and Euphorbiaceae (23.16). The frequency dis- picture of plant resources and thereby understanding the tribution of all the species was highly skewed with Mememecylon umbellatum, Syzygium cumini, Olea forest dynamics over the entire Western Ghats eco-region dioica, Catunaregam spinosa and Terminalia elliptica level. The present work is part of a 4-year on-going study accounting for 50% of the population. Twenty-three (2004–08) intensively samples plant resources at an en- species were represented by only one individual in the tire eco-region level and forms a part of a series of publi- transects sampled, indicating the underlying log- cations to be followed. normal distribution. Puri et al.13 and Pascal14 classified the mid-elevation tracts of NWGs under a single Memecylon–Syzygium– Keywords: Chandoli National Park, Memecylon– Actinodaphne (M–S–A) type based on the criteria of Syzygium–Olea floristic series, vegetation composition, dominance–abundance–fidelity of species. However, the woody species diversity. need and importance of quantitative studies in classifying vegetation types have been emphasized by several work- ers15,16. The idea behind this article emerged from one THE Western Ghats of India along with neighbouring Sri 17 1 such quantitative assessment of the KMTR . Also, Ghate Lanka is one of the 34 global biodiversity hotspots . It 15 harbours tropical humid forests, known to be amongst the et al. , while working on forests of NWGs, reported exis- most diverse, most productive and most threatened bio- tence of another plant community along with the standard 2,3 M–S–A type. In the context of rapid changes a landscape logical communities of the world . It constitutes a chain witnesses owing to threats such as forest loss, vegetation of mountains running parallel to the west coast of India is expected to vary over small spatial scale. We investi- (approx. 1600 km length and 5–15 km width) and ranges gated in detail the composition, abundance and diversity from 8°N to 20°N lat. The northern ranges of the Western of woody species (GBH ≥15 cm) at Chandoli National Ghats, which lie in Maharashtra, make about one-third of Park (CNP), to provide descriptions of vegetation and its total length. As elsewhere in the tropical countries, all species distribution exclusively covering an entire PA or most of the original vegetation cover of the Western from the NWGs. CNP provides an excellent opportunity Ghats has been influenced to varying extents by human- to study diversity and density estimates for various rea- kind over thousands of years4. sons: (a) It is one of the least explored areas of NWGs because of its rugged terrain and inaccessibility. Till date only one research paper18 is dedicated towards botanical *For correspondence. (e-mail: [email protected]) exploration of a part of this area in 1975 that too before it CURRENT SCIENCE, VOL. 95, NO. 5, 10 SEPTEMBER 2008 637 RESEARCH ARTICLES was declared a PA and detailed investigations are lack- of wildlife protection, conservation awareness and tourism, ing. (b) The area experienced human disturbance prior to as none of the other three Project Tiger sites in the state, its declaration as a PA. But now it provides an ideal case Tadoba, Melghat and Pench, are in the NWGs ranges. to study forest dynamics. (c) Recently, CNP along with two other wildlife sanctuaries from NWGs have been Methods proposed as World Heritage Sites to UNESCO. Thus, as- sessing and understanding conservation potential of the The entire area of the CNP was divided into ten grids of area will help in planning better conservation strategies. 6.25 km × 6.25 km each. A belt transect of 1000 m × 5 m was laid in each grid. This amounts to 0.01% of the sam- Study area pling intensity, which is a standard requirement for such enumerations21. Woody species were enumerated for in- Northern Western Ghats dividual height and girth (≥15 cm) estimates. Shrubs were recorded at the beginning and end of the transects by lay- The northern ranges of the Western Ghats, popularly ing sub-plots of 5 m × 5 m. The belts were located such known as Sahyadri (15°30′–20°30′N lat., 73°–74°E long.), that they incorporate significant environmental gradient lie in Maharashtra. The vegetation is more or less in the of the grid. This is essential to get a representation of the form of fragmented patches in contrast to continuous habitat variability. Grids with patchy vegetation were stretches of forests in SWGs. Presence of numerous barren, sampled by breaking the entire transect into maximum of rocky, lateritic plateaus, locally known as ‘sadas’, is a four sub-transects of varying lengths. Twenty-six such unique feature of the NWGs. It supports characteristic sub-transects were laid in the entire CNP. All the indi- ephemeral flush vegetation harbouring monotypic genera, viduals were identified up to species level. The unidenti- many of which show restricted or narrow distribution19. fied specimens were photographed and/or collected and However, it is impoverished on account of overall woody identified later by consulting herbaria and the literature. species richness, one of the reasons being absence of species- The overall checklist of the grid, including trees, shrubs rich forest types, such as Myristica swamps and shola and herbs was also prepared. forests that are unique to the SWGs. Two indices were calculated for vegetation analysis: Species importance value (SIV; also popularly known as Chandoli National Park importance value index) for species and family impor- CNP (earlier declared a wildlife sanctuary in 1985) is located tance value (FIV) for families. at the junction of four districts, viz. Sangli, Satara, Kol- SIV was calculated as follows: hapur and Ratnagiri, in western Maharashtra. It spreads SIV = Relative frequency + relative density + relative domi- along the crest line and lies between Koyna and Radha- nance. nagari Wildlife Sanctuaries (17°15′N–17°07′N lat. and Relative frequency = (Number of plots containing a spe- 73°44′E–73°51′E long.). Its expanse spreads over an area 2 cies × 100)/Sum of frequencies of all species. of 317.67 km along the backwaters of Vasant Sagar res- Relative density = (Number of individuals of a species × ervoir (Figure 1). The terrain is inaccessible and hilly; 100)/Total number of individuals of all species. most of the hills are flat-topped with steep slopes sustain- Relative dominance = (Basal area of a species × 100)/ ing grasslands and scrub vegetation on the hilltops and Total basal area of all species. dense, tall forests on the slopes and valleys. The altitude of CNP ranges from 589 to 1044 m. The underlying rock FIV was calculated according to Ganesh et al.17. is the igneous trap – basalt and the superficial rock is lat- erite in general. The soil is gravelly, red or reddish-brown FIV = Relative density + relative diversity + relative in colour. The area receives an average annual rainfall of dominance. about 6200 mm, most of which is distributed over the pe- Relative density = (Number of individuals of the species × riod of June–September. The catchment is drained by a 100)/Total number of individuals in the sample. number of seasonal and perennial streams. Relative diversity = (Number of species in the family × The area also supports diverse fauna, including the en- 100)/Total number of species in the sample. dangered Panthera tigris (tiger), Panthera pardus (leop- Relative dominance = (Basal area of the family × 100)/ ard), Bos gaurus (gaur), Melursus ursinus (sloth bear), Total basal area in the sample. Ratufa indica (giant squirrel), Manis crassicaudata (pan- golin), etc. Recently, CNP along with two wildlife sanc- The log series distribution model was fitted to the tuaries, Koyna and Radhanagari, has been proposed as a pooled data as given by Magurran22. The log series takes World Heritage Site (Western Ghats–Sahyadri Sub- the form: Cluster)20. Besides, CNP in conjunction with Koyna WLS 2 ααx23xx αn (423.55 km ) was proposed to be notified as a Project Ti- α x, , ,..., , ger Reserve.