Floristic diversity of Bhimashankar Wildlife Sanctuary , northern Western Ghats , Maharashtra , India

Bhimashankar Wildlife Sanctuary (BWS) is located on the crestline of the northern Western Ghats in Pune and Thane districts in Maharashtra State. It was notified in October 1985 towards conservation of the state animal of Maharashtra, the Giant Squirrel Ratufa indica ssp. elphinstonii . Although an important protected area in the Western Ghats, due to the lack of a comprehensive report, an assessment of floristic diversity of BWS was done from 2009 to 2016. The results revealed that forest types and microhabitats are diverse in the sanctuary. Major forest types are western subtropical broad leaved hill forest to moist deciduous types with a few included small patches of evergreen forests. The rich flora of the sanctuary is represented by a total of 1,142 angiospermic taxa at species and infraspecific level spread over 619 genera and 124 families. Of these 1,094 taxa are wild, which belong to 118 families and 586 genera. Rest of the taxa are planted (34), and 14 introduced. The taxa are classified as per the APG IV. The wild taxa include 20 magnolids, 285 monocots, one Ceratophyllales and 788 eudicots. Out of these, 217 taxa are Indian endemics; which comprise about 19.84% of the total number of wild taxa (1,094) in the sanctuary and 5.04% of total Indian endemics (4,303). Total 53 taxa are under different threat categories according to IUCN. BWS harbours a significant extent of angiosperms in a very small geographic area.

1 0 . 1 1 6 0 9 / j o t .3 0 7 4 .9 .8 . 1 0 4 9 3 -1 0 5 2 7 n e s v fi s fi t h t p : / / t h r e a t e n e d t a x a .o r g / A b o u t _ J o T T F o r A r fi c l e S u bm fi s s fi o n G u fi d e l fi n e s v fi s fi t h t p : / / t h r e a t e n e d t a x a .o r g / S u bm fi s s fi o n _ G u fi d e l fi n e s F o r P o l fi c fi e s a g a fi n s t S c fi e n fi fi c M fi s c o n d u c t v fi s fi t h t p : / / t h r e a t e n e d t a x a .o r g / J o T T _ P o l fi c y _ a g a fi n s t _ S c fi e n fi fi c _M fi s c o n d u c t F o r r e p r fi n t s c o n t a c t < fi n f o@ t h r e a t e n e d t a x a .o r g >

INTRODUCTION
The Bhimashankar Wildlife Sanctuary (BWS) is one of the five wildlife sanctuaries located along the northern Western Ghats in Maharashtra.It was notified on 10 October 1985 by the Government of Maharashtra State (Governor of Maharashtra 1985) as a step to conserve the state animal, the Giant Squirrel Ratufa indica spp.elphinstonii.The sanctuary is named after the Bhimashankar temple (one of the 12 jyotir-linga (self emerged) Shiva temples in the country) located inside the sanctuary and surrounded by a sacred grove.It is an important pilgrimage as well as a famous tourist destination.
It is reported to inhabit more than 529 faunal species including the Giant Squirrel, Leopard, Golden Jackal, Mouse Deer, among others; about 20% of the mammals reported are in Schedule-1 of Wildlife Protection Act (Anonymous 2009).It has also been identified as an Important Bird Area (IBA) by BirdLife International as it harbours globally threatened species like, Greater Spotted Eagle, Nilgiri Wood Pigeon, Malabar Parakeet and White-backed Vultures.
Botanically, the area of the sanctuary has not yet been completely explored.Janardhanan (1966) while studying the flora of Khed Taluka covered a part of BWS, especially the part falling in the Khed Taluka of Pune District.He reported a total of 838 taxa of angiosperms from Khed comprising 315 taxa from the area covered within the sanctuary.He further reported some medicinal plants from the area, especially from Bhorgiri and the temple area of the sanctuary (Janardhanan 1963(Janardhanan & 1965)).Mahabale (1987) in the Gazetteer of Maharashtra State mentioned only four types of vegetation and cited the work by Janardhanan.The Gazetteer did not provide any list of plants of Bhimashankar, unlike the other areas like Katraj Ghat and Purandhar in the district; because the work done so far was not comprehensive to cover the complete area of the sanctuary.It emphasized a need of comprehensive exploration of the plants of BWS.Pande (2005), in the profiles of the national parks and wildlife sanctuaries of Maharashtra State, enumerated 291 plant taxa in BWS with the acceptance that their aim was not to make an inventory of the sanctuary and the records of flora are based on casual documentation.Therefore, though it is an important document it is not a comprehensive one to be considered as the flora of BWS.Meanwhile Jagdale (1994) studied the ecology of the area and concluded that the ecosystem of the sanctuary is quite unique and very fragile, so it requires priority for conservation and minimization of local use of natural resources.Upadhye et al. (1994) documented some ethno-medicinal plants from the region.Even in the recent Gazetteer (Naik 2006), there is no citation of vegetation or any floristic account from the sanctuary.Watve (2013) studied the rocky plateaus of western Maharashtra and reviewed the ephemeral flora occurring on them, covering two localities, namely, Ahupe and Kondhaval within the sanctuary.A single plant, Chukrasia tabularis A. Juss.was reported as a northernmost extended distribution from the sacred grove of Ahupe by Kulkarni et al. (2014), emphasizing the importance of sacred groves as conservatory of plants.This species was already recorded by Pande (2005) to occur in the sanctuary area, but without a specimen.Thus, in this scenario the report by Pande (2005) is found to be a significant document but not a comprehensive one.The authors of the present study explored Pune District including BWS before this work for diversity and distribution of medicinal plants (Rahangdale & Rahangdale 2012) and pteridophytes (Rahangdale 2013).Thus, BWS is poorly explored in terms of angiosperm floristics.The strategic plan of MoEFCC (Anonymous 2012) has its second objective for conservation of existing forests, wildlife and water resources and survey of various areas for identification of new species; which in turn is in accordance with the National Biodiversity Action Plan's objective 4.7; emphasizing on the documentation of the biological wealth of India (Arora & Bhatt 2008).
Therefore, it was a need of the time to bring on record the complete flora of the sanctuary so that, it would be a baseline for designing plans for conservation, management of resources and anthropocentric developments within and around the sanctuary.Considering the above facts, an exploration of BWS was undertaken to bring out a complete record of floristic diversity of the sanctuary.

Study area
The BWS is spread over four forest ranges in two districts-Pune (Khed and Ghodegaon ranges) and Thane (Karjat and Alibaug ranges).It covers an area of 130.78km 2 from eight villages in Pune District and reserve forest along the west slopes of the crestline in Thane District between 19. 0226361-19.2305555 N & 73.4827777-73.6308333 E. The elevation ranges between 340m on the west side and 1,208m above mean sea level at the Nagphani (Hindi: Snake's Hood) point.Two important rivers of the state, Bhima and Ghod, which are tributaries

Floristic diversity of Bhimashankar Wildlife Sanctuary
Rahangdale & Rahangdale of river Krishna, originate in the sanctuary.It has a high unbroken ridge of the Western Ghats (WG) composed of basaltic lava passing in a north-south direction.The topography includes spurs of the WG running towards the eastern plains and steep slopes and valleys towards the west in the Konkan region (Fig. 1).Pande (2005) identified hill slopes, ridges, peaks, spurs, valleys, pools, rocky plateaus, cliffs, gorges, ravines, rocky and sandy stream basins as important physical features.These physical features make the sanctuary a complex of microhabitats.

Data collection
The study materials comprise the flora of BWS.Some information was also taken from previously collected specimens and related documentation about the sanctuary as preliminary work done during the visits to the sanctuary as the authors were extending their services to the department of forests as visiting botanists to Ghod Forest Division.The surveys were undertaken to cover all seasons and the whole area from June 2009 to September 2016.The surveys were extensive and critical to record the information.Identification of specimens was done in the field using different floras (Cooke 1958;Almeida 1996Almeida -2009;;Sharma et al. 1996;Singh & Karthikeyan 2000;Singh et al. 2001;Potdar et al. 2012).

Laboratory studies
Only unique specimens were collected for confirmation of identity and deposition in the herbarium.Specimens were processed for mounting following standard protocol as per Jain & Rao (1977), and voucher specimens were deposited in the herbarium of Botany Department, B.J. College, Ale.The identity of the specimens collected was confirmed by comparison with the specimens at BSI, Pune; previously confirmed specimens by SSR during her doctoral study and the project works, which are also deposited in the herbarium of Botany Department, B.J. College, Ale having more than 3000 specimens of about 2,000 taxa and AHMA, Pune.Systematic position and accepted names were checked using The Plant List (2017), while the status was checked from IUCN (2016) website.The classification system followed is APG IV (APG 2016) and all the taxa are arranged as per the system; endemism was also checked following Singh et al. (2015).Documentation of vegetation and forest types was done using the types and subtypes given by Champion & Seth (1968) with a few variations.Microhabitats, especially on the plateaus were also recorded following the types given by Watve (2013), and Rahangdale & Rahangdale (2014).

RESULTS
Results of the study are presented under two subheads: (i) vegetation cover, and (ii) floristic diversity.The vegetion cover comprises overall vegetation, forest types, their distribution in the sanctuary and composition of each type with details of vegetation stratification; while the complete angiospermic diversity is presented under the second subhead.The taxa (genera, species and taxa at infraspecific level) are alphabetically listed under taxonomic treatement of families according to APG IV.The serial numbers of the families in the system are also given.For sake of ease the subfamilial grouping is retained in Fabaceae, Acanthaceae and Apocyanaceae.

Vegetation cover
The major vegetation cover is of western subtropical broad leaved hill forests described by Champion & Seth (1968), also termed as montane broad leaved semievergreen forest covering most of the area of BWS.Due  This vegetation of monsoon flora along with the grasses confers a mass effect of blooming during and post monsoon periods to the plateau vegetation.This mass blooming also indicates successive changes occurring in the composition of dominant species on these plateaus.These areas show more herbaceous diversity because of the microhabitats supporting short-lived herbaceous taxa.

Floristic diversity
The number of recorded taxa at specific and infraspecific levels are 1,142 belonging to 619 genera and 124 families of angiosperms (Table 1).The genus to species ratio is 1:1.85.Of these 1094 taxa are wild, which belong to 118 families and 586 genera (Table 1 Janardhanan (1966) while studying the flora of Ked Taluka involving some part of Bhimashankar comprising the Bhimashakar Sacred Grove, Nagphani point, Hanuman Talao, Bhakadevi Hill and Bhorgiri had reported a total of 315 taxa from the sanctuary area, comprising 310 wild taxa and five cultivated/introduced.These 310 wild taxa are about 28.34% of 1,094 taxa.Of these 315 taxa, a total of 13 taxa could not be collected by the authors during the present study, but included on the authority of Janardhanan (1966) and marked as '**' in the tables.Janardhanan also reported 54 taxa only on the authority of previous herbarium specimens, collected and deposited at different herbaria by W.A. Talbot, Z. Kapadia, N.A. Irani, and D.P. Panthaki in the Blatter Herbarium, Mumbai (BLAT); J.A. Vasavda and G.S. Puri in Botanical Survey of India, Western Circle, Pune (BSI) and by V.D. Vartak in Agharkar Herbarium, Pune (AHMA).Pande (2005) reported a total 291 species of 241 genera of 78 angiosperm families, comprising 277 wild and 14 cultivated/introduced taxa.This number (277)    Pande (2005) might have mistakenly included this name.After verification of the available specimens of this genus it is confirmed that this species does not occur in the sanctuary, and therefore it is not included in the present study.These six taxa were also not recorded by Janardhanan (1966); therefore the occurance and identity of these taxa needs further revision, therefore they are excluded from the present list of taxa occurring in the sanctuary.

DISCUSSION
The sanctuary has about 19.84% endemic taxa of the total angiosperms (1,094) recorded from it.Ahmedullah & Nayar (1987) reported 1,932 endemic taxa for peninsular India, of which 694 were reported to be found in Maharashtra State (Mishra & Singh 2001).There are 4,303 endemic angiosperms in India (Singh et al. 2015) of which penninsular India has 2,592 taxa, while 2,116 endemics are in the Western Ghats.During the present study, 217 Indian endemic taxa were recorded in BWS, which is 5% of the total Indian endemics.A total of 58 genera are reported to be endemic to India (Singh et al. 2015); out of that 15 (25.86%) genera are represented by one or more taxa in the sanctuary during the present study.This is a very significant number as this small sanctuary harbours such an extent of endemic taxa.These facts represent the richness of flora in BWS.
Out of 1,094 taxa, 53 (4.85%) are found to be categorised by IUCN (2016)  threatened taxa, BWS is very rich and plays a significant role in their conservation.Composition of flora and different microclimates are determined by growth forms (habit) of the taxa at a particular habitat.Therefore, habit-wise analysis of plant taxa in the sanctuary is also important.Herbs dominate flora with 56.03% (613 taxa) followed by 16.73% (183 taxa) trees, 15.63% (171) shrubs, 9.96% (109) climbers and 1.65% (18 taxa) are epiphytes.Trees and shrubs are dominant in the sanctuary, constituting major vegetation of it and supporting diverse wildlife.Continuous canopy of semi-evergreen and evergreen forests is essential for survival of the giant squirrel and other arboreal faunal elements.The tropical regions of the world generally have more diversity of tree species as compared to subtropical forests.The diversity of trees in BWS is quite good considering the total geographic area 130.78km 2 .
Compared to available data from other protected areas of India, BWS represents a high number of angiosperm taxa.A total of 722 species of flowering plants were reported from Bhagwan Mahavir (Molem) National park located in Goa (240km 2 ) (Datar & Lakshminarasimhan 2013); 923 species from Anshi National park, Karnataka (340km 2 ) (Punekar & Lakshminarsimhan 2011) and 1,339 species and 16 subspecies from Rajiv Gandhi National Park, Karnataka (642km 2 ) (Manikandan & Lakshminarsimhan 2013).All these protected areas cover significantly larger geographic areas as compared to the BWS, and still the number of taxa recorded in the BWS is higher.The protected areas which are a little distantly located are also compared and found that Mudumalai Sanctuary (321km 2 ), Tamil Nadu, which is a part of the southern WG having evergreen and semi-evergreen forests has a total of 157 tree species (Suresh et al. 1996).The Nallamalai Hill ranges in the Eastern Ghats of Andhra Pradesh having a total area of 6,740km 2 have 281 (18.2%) tree species out of 1,541 total angiosperms (Reddy et al. 2008).In this perspective BWS has a significant richness of tree species also.
Besides the naturally occurring plant taxa, total 48 planted / introduced taxa are also recorded.These belong to 28 families and 44 genera.Of these, about 20 taxa are weeds.Some of the weed species are invasive in the sanctuary and are fast enchroaching new habitats, while others show an increasing trend in their populations.These invasive species are causing an imbalance in the natural set of vegetation in BWS.Fast spreading species are Lantana camara, Hyptis suaveolens, Eupatorium adenophorum, Argemone mexicana, Alternanthera spp.and Cosmos bipinnatus.Lantana camara and Eupatorium adenophorum are enchroaching shrubby vegetation and understorey of the forests, while Hyptis suaveolens and Cosmos bipinnatus are replacing the Impatiens-Senecio-Smithia ground vegetation along the paths and slopes.Alternanthera spp.are replacing the populations of Nanothamnus sericeus from plateaus, which is a serious threat, as it is an endemic and an endangered taxon.Increasing trend of populations or increase in the extent of occurance has been observed for some weed species such as Trianthema portulacastrum, Flaveria trinervia, Blainvillea acmella, Nicandra physalodes and Lagasca mollis.All these invasive weed species cause a serious threat to the native flora of BWS.
It is significant to note that, the evergreen forest patches as well as plateau vegetation are highly sensitive to human interference in the form of increased demand for firewood and grazing.Trampling by the pilgrims and cattle are added hazards due to an increasing number of tourists and pilgrims.Similar results were also recorded by Pande (2005).In the document of MoEFCC, the Ecological Status of Northern Western Ghats, it is also emphasized that the Bhimashankar forests are under very high stress of pilgrimage, tourism and the garbage generated by these activities (Anonymous 2010).Both degradable and non-degradable garbage pollute the water sources and also eliminate the ground flora at some places in the sanctuary.

CONCLUSION
The present investigation provides first hand comprehensive information on the floristic diversity of angiosperms of BWS.The number of species is quite good in terms of the geographic area of the sanctuary; comprising 19.84% endemic taxa which are about 5.04% of total Indian endemics.The varied topography supports this extent of angiosperm diversity in BWS.Rahangdale & Rahangdale (2014) reported that, more diversity is associated to the areas having more diverse topographical features constituting varied type of microhabitats supporting different life forms.The results of the present study are also in corroboration with the previous study of two locations in the northern Western Ghats adjoining the Bhimashankar Wildlife Sanctuary.
T h r e a t e n e d T a x a T h e J o u r n a l o f T h r e a t e n e d T a x a fi s d e d fi c a t e d t o b u fi l d fi n g e v fi d e n c e f o r c o n s e r v a fi o n g l o b a l l y b y p u b l fi s h fi n g p e e r -r e v fi ew e d a r fi c l e s o n l fi n e e v e r y m o n t h a t a r e a s o n a b l y r a p fi d r a t e a t www .t h r e a t e n e d t a x a .o r g.A l l a r fi c l e s p u b l fi s h e d fi n J o T T a r e r e g fi s t e r e d u n d e r C r e a fi v e C omm o n s A t r fi b u fi o n 4 .0 I n t e r n a fi o n a l L fi c e n s e u n l e s s o t h e rw fi s e m e n fi o n e d .J o T T a l l ow s u n r e s t r fi c t e d u s e o f a r fi c l e s fi n a n y m e d fi um , r e p r o d u c fi o n , a n d d fi s t r fi b u fi o n b y p r o v fi d fi n g a d e q u a t e c r e d fi t t o t h e a u t h o r s a n d t h e s o u r c e o f p u b l fi c a fi o n .O P E N A C C E S S P a r t n e r www .t h r e a t e n e d t a x a .o r g I S S N 0 9 7 4 -7 9 0 7 ( O n l fi n e ) | I S S N 0 9 7 4 -7 8 9 3 ( P r fi n t ) B u fi l d fi n g e v fi d e n c e f o r c o n s e r v a fi o n g l o b a l l y J o u r n a l o f T h r e a t e n e d T a x a P u b l fi s h e r / H o s t F o r F o c u s , S c o p e , A fim s , P o l fi c fi e s a n d G u fi d e l fi

Figure 1 .
Figure 1.Bhimashankar Wildlife Sanctuary (BWS): Location in India, Topography and map.(Green cover shows researve forests in the sanctuary)

Table 3 . The families with more than 20 representative taxa in BWS.
Smilax guianensis Vitman, Syzygium gardneri Thwaites, and S. kanarense (Talbot) Raizada are also not reported yet from Maharashtra State by any of the taxonomists.Smilax guianensis Vitman is distributed in the South American region and not reported from other parts of the world.