India is one of the world's top 12 mega-diversity Nations and out of its total plant wealth, about 18,000 species of flowering plants have been described. Estimates of other plant taxa include 5,000 species of algae, 1,600 lichens, 20,000 fungi, 2,700 bryophytes and 600 pteridophytes.  This biological diversity providing subsistence to the human race in terms of food, medicine, housing, etc. is being continuously depleted due to intense anthropogenic pressures. It has been observed that nearly 1,000 plant species are put in the categories of medicinal and wild relatives of economically important crops and fruit trees those are under the threat of extinction.

Himalayas, are one of the largest and youngest mountain chains in the world and cover roughly 10% of India total land surface. Variations in terms of its size, climate and altitudinal ranges, have created environments those are unique and characteristic to this region only. The diverse climate and the varied environmental conditions prevailing in the lap of Himalayas support diverse habitat and ecosystems with equally diverse life forms. Himalayas otherwise known for its rich and diverse plant wealth had shown a rapid decline in population of many plant species in recent past. Some of them have already been lost whereas many of them are in the verge of extinction.  If suitable steps to conserve the Himalayan flora not taken well in time, the delay may lead to the total extinction of rare and valuable plants. The current decline in biodiversity largely through human activities is a serious threat to our ecosystem.  Hence, attempts are on to preserve this biodiversity in-site and ex-situ conservation.  

Tundah wildlife sanctuary was established in 1962 in Chamba district of Himachal Pradesh. It covers an area of about 64.22 sq km. Altitude of this sanctuary varies from 2074 m to 5500 m above msl whereas the climate ranges from temperate to alpine. The sanctuary represent the flora of temperate to alpine climate and inhabitants of villages in and around the sanctuary have got their rights pertaining to grazing, collection of timber, fuel wood, fodder, pine needles and other minor forest produce. In addition, graziers also get permits for grazing of their cattle inside the sanctuary. In this sanctuary, continuous removal of plant species for various uses and overgrazing by migratory and other livestock infact, have resulted in loss of biodiversity. If these naturally occurring plant resources are not conserved timely then they may soon become extinct. Keeping this in view attempts were made to assess the plant diversity including documentation of the medicinal plants found in Tandidhar of Tundah wild life sanctuary of district Chamba, Himachal Pradesh.

The present study was conducted in Tandidhar of Tundah wild life sanctuary in district Camba of Himachal Pradesh during, 2020 at an elevation of 2100- 5500m. The study site was situated at N 32o31′52.4″ to N 32o30′48.8″ latitude and E 76o 26′58.9″ to E 76o 26′11.8″ longitude. The whole area of the valley was divided into three altitudes i.e. 2250-2750m, 2750- 3250m and 3250-3750m for conducting the phyto-sociological study. Quadrats of size 10m × 10m, 3m × 3m and 1m×1m laid out randomly for enumerating trees, shrubs and herbs + regeneration respectively. The seedlings were considered as herbs whereas saplings as shrubs. The vegetation data was analysed for density, frequency and abundance as per Curtis and McIntosh (1950). The relative values of density, frequency and dominance were summed to get Importance Value Index (IVI) of individual species. The abundance to frequency ratio (A/F) of different species was determined for eliciting the distribution pattern of the floral elements.  This ratio indicates regular (<0.025), random (0.025 to 0.050) and contiguous (>0.050) distribution (Curtis and Cottam 1956).  The plant species diversity was calculated following Shannon-Wiener diversity Index (H) (Shannon-Wiener, 1963).

Dominance Index (C) was measured by Simpson’s Index (Simpson, 1949).  

Where Ni = Importance value of species i and N= Total importance value of all the species.

 Richness Index was estimated as per Margalef (1958) i .e. R = S-1/ln N

Evenness Index was calculated as per Hill (1973) i. e. E = H/ ln S

Where S= Total number of species, N= Total number of individuals of all the species, H = Index of diversity.

Total number of plant species was 125 belonging to 113 genera and 47 families. The dominant families were Asteraceae, Fabaceae, Geraniaceae, Lamiaceae and Orchidaceae. At an elevation of 2250-2750m, total number of tree species was 4 (Table 1).  Pinus wallichiana was the dominant species having maximum density (400.00 ha-1), abundance (6.15) and frequency (65.00%). This was followed by Picea smithiana (175.00 ha-1) in term of density. On the basis of IVI, Pinus wallichiana recorded the highest value (184.24) followed by Picea smithiana (84.25) and Aesculus indica (17.30). The community identified was Pinus wallichiana-Picea smithiana in this elevation. The ratio of abundance to frequency (A/F) indicates that the distribution pattern of all the species was contiguous. The general preponderance of contiguous distribution in vegetation has been reported by several workers (Kershaw, 1973; Singh and Yadava 1974; Kunhikannan et al. 1998).

The plant communities are never static but are always in a changing state and their studies are of great significance for management of grassland providing valuable information on the diversity and dominance of constituent species of the communities (Santvan, 1993). Billings (1978) while studying the alpine vegetation found it most susceptible to human and animal damage through trampling, camp sites, proliferation of trails which result in exposing soil and in irreversible ecosystem changes and extinction of certain species. The A/F ratio indicates that the distribution pattern of most of the species was contiguous. However, some species showed random distribution. The general preponderance of contiguous distribution in vegetation has been reported by several workers (Kershaw, 1973; Singh and Yadava 1974; Kunhikannan et al., 1998; Radha and Puri 2018).) while working in different ecosystem. The species present in alpine pasture were analyzed for different growth form classes and the contribution of all forbs, short forbs, cushion and spreading forbs was 41.46%, 52.44% and 6.01% to the total flora. The results are in conformity with the earlier studies made by Singh (1967); Santvan (1993); Verma et al. (2008). In the present study, 41.46 % tall forbs, 52.44 % short forbs and 6.10% cushion and spreading forbs were observed. Similar findings were reported by different workers while conducted the study in alpine pasture. Santvan (1993) for the alpine pasture near Rahla, reported 22.5% tall forbs, 45.0% short forbs and 32.5% cushion and spreading forbs. Verma et al. (2008) recorded 29.33% tall forbs, 54.66% short forbs and 16.0% cushion and spreading forbs for alpine pasture of Talra, Himachal Pradesh. The short forbs usually have hairy leaves which protect them against frost. The cushion and spreading forbs are characterized by various adaptive features such as leaf rosettes, dense cushion, hairy growth etc. which provide relative protection against the harsh conditions of alpine environment. The annuals form a major component in the alpine and high sub alpine environment. It is difficult for most species to complete the entire life cycle in a single cold growing season (Bliss, 1971; Saville, 1972; Santvan, 1993; Verma et al., 2008).

Table 2: Phytosciological attributes of the shrub species in Tandi Dhar at an altitudinal zonation of 2250-2750m.

Table 3: Phytosciological attributes of the herb species in Tandi Dhar at an altitudinal zonation of 2250-2750 m.

Among 9 shrub species at elevation 2750-3250m (Table 5), Viburnum erubescens was the dominant species having maximum density (3944.44 ha-1) and frequency (30.00%) followed by Rabdosia rugosa (2555.56 ha-1) interms of density. In terms of abundance, Cotoneaster microphyllus (18.33) had maximum value. Viburnum erubescens recorded the highest value of IVI (88.09) followed by Desmodium multiflorum (42.59) and Rabdosia rugosa (40.91). The distribution pattern of all the species was contiguous. 

Table 4: Phytosciological attributes of the tree species in Tandi Dhar at an altitudinal zonation of 2750-3250m.

Table 5: Phytosciological attributes of the shrub species in Tandi Dhar at an altitudinal zonation of 2750-3250m.

Note: *Saplings 

In case of herbs including regeneration there was 58 species at 2750-3250m elevation (Table 6). Trifolium repens was the dominant species having maximum density (2.43 m-2), abundance (14.60) and frequency (26.67%). This was followed by Plantago lanceolata (0.93 m-2) in term of density. On the basis of IVI, Trifolium repens recorded the highest value (25.10) followed by Anaphalis triplinervis (20.23) and Plantago lanceolata (16.97). The lowest IVI (1.10) was observed for Spiranthes sinensis. The ratio of abundance to frequency (A/F) indicates that the distribution pattern of all the species was contiguous. 

Table 6: Phytosciological attributes of the herb species in Tandi Dhar at an altitudinal zonation of 2750-3250m.

Among 5 shrub species at elevation 3250-3750m (Table 8), Rhododendron campanulatum was the dominant species having maximum density (4027.78 ha-1), abundance (23.60) and frequency (20.00%). This was followed by Juniperus cummunis (3277.78 ha-1) interms of density. Rhododendron campanulatum recorded the highest value of IVI (89.74) followed by Juniperus cummunis (75.15) and Salix fraglis (70.87). The distribution pattern of all the species was contiguous. 

Table 7: Phytosciological attributes of the tree species in Tandi Dhar at an altitudinal zonation of 3250-3750m.

Table 8: Phytosciological attributes of the shrub species in Tandi Dhar at an altitudinal zonation of 3250-3750m.

Table 9: Phytosciological attributes of the herb species in Tandi Dhar at an altitudinal zonation of 3250-3750m.

Table 10: Dominance index (C), diversity index (H), richness index (R) and evenness index (E) for tree, shrub and herb at different elevations in Tandi Dhar of the sanctuary.

Total 61  important plants of medicinal value found in Tandi Dhar of Tundah wild life sanctuary in district Chamba of Himachal Pradesh were compiled following Chopra et al. (1956); Kirtikar and Basu (1987); Kala (2002). These include; Achillea millefolium, Aesculus indica, Ajuga bracteosa, Anaphalis triplinervis, Anemone obtusiloba, Arnebia benthami, Artemisia parviflora, Aesculus indica,  Anaphalis triplinervis, Anemone obtusiloba, Arnebia benthamii, Artemisia parviflora, Aster molliusculus, Berberis lycium, Bergenia ciliata, Callicarpa macrophylla, Capsella bursa-pastoris, Cirsium wallichii, Clematis grata, Corydalis ramosa, Dactylorhiza hatagirea, Delphinium brunonianum, Desmodium triflorum, Euphorbia cognata, Fragaria vesca, Galium asperifolium,  Geranium pratense, Geranium wallichianum, Geum elatum, Habenaria pectinata, Inula cappa , Juniperus communis, Jurinea dolomiaca, Lactuca dissecta, Malva rotundifolia, Mentha longifolia, Micromeria bifloria, Nepeta erecta, Origanum vulgare, Oxalis corniculata, Phlomis bracteosa, Plantago lanceolata, Polygonatum verticillatum, Polygonum capitatum, Potentilla atrosanguinea, Primula denticulata, Ranunculus diffusus, Rhododendron campanulatum, Rubia cordifolia, Rumex nepalensis, Salvia moorcroftiana, Sarcococca saligna, Selinum tenuifolium, Senecio graciliflorus, Taraxacum officinale, Thalictrum foliolosum, Thymus linearis, Trifolium repens, Urtica dioica,  Verbascum thapsus and Viola canescens

Out of 61 medicinal plant species recorded from theTandidharof Tundah Wildlife Sanctuary, 9species viz;  Arnebia benthamii, Bergenia stracheyi, Betula utilis, Dactylorhiza hatagirea,  Juniperus communis, Jurinea dolomiaea, Polygonatum verticillatum,  Rhododendron campanulatum and Selinum tenuifolium, fall in the category of threatened plants when compared with the available literature like Red Data Book and CAMP Reports. The less population of medicinal plants is due to habitat alteration, narrow range of distribution along with other factors. A major threat is for the species those are uprooted and their underground parts such as rhizomes, tubers, bulbs and roots are used in medicine. The habitat of most of the plant species have shrunk due to expansion of human population and environmental degradation primarily due to heavy live stock grazing, uncontrolled and unscientific harvest of species, unregulated tourism and construction of roads etc. The better conservation of natural resources can be done by inclusion of a section on the plant conservation especially of rare and endangered medicinal plants in the wild life protection act, promotion of community based conservation, ex-situ conservation through tissue culture, developing cultivation technologies and nurseries of medicinal plants and conducting of regular training on the procedure of medicinal plants collection, processing among the local people, traders and real stake holders.