INTRODUCTION

Himachal Pradesh, located in Northern India, shares its border with Jammu & Kashmir in theNorth, Punjab in the West and South West, Uttarakhand in the South East, Tibet (China) in the East and Haryana in the South and lies between 75°47'55''–79°04'22'' N and 30°22'04''–33°12'40'' E. It is the 18th largest state by geographical cover (55,673 sq. km) and 21st largest state in terms of population of India. The state spreads over an area of 55,673 sq. km comprising of 595 km of mountain ranges spreading along the Indus-Sutlej river system, their height varying from 244–6975 m above sea level. Physiographically, the state can be recognized into 3 zones i.e., i) The Outer Himalayas or The Shivaliks, ii) The lesser Himalayas or the Central Zone and iii) The Great Himalayan and Zaskar or the Northern Zone, whereas administratively, it has been divided into 12 districts, with Shimla as the capital city.

Topography and Soil: Himachal Pradesh is situated in the western Himalayan biotic province within the Sino-Himalayan subzone of the Boreal biogeographic zone. The entire region of this state is hilly with altitude ranging from 244–6975 m above sea level. The soil type and texture varies from place to place in the state. The soil below 1000 m altitude is generally sandy loam varying from light grey to brown, and on hilly slopes between 1000–1600 m altitude generally loam or silt loam with fine texture from grey to black, between 1600–2200 m altitude varying from silt loam to dry loam with less gravel and dark brown and above 2200 m, the soil is silty loam to loams, dark brown and acidic in nature.

Climate: There is a great diversification in the climatic conditions of the state due to variation in elevation (250–7000 m). It varies from hot and sub-humid tropical (250–900 m) in the southern low tracts, warm and temperate (900–1800 m), cool and temperate (1900–2400 m) and cold alpine and glacial (2400 to above 5000 m) in the northern and eastern high mountain ranges. The year is divided into three seasons, i.e. cold (October to February), hot (March to June) and rainy (July to September). The average annual rainfall of the state is about 182 cm. The northern region has less rainfall as compared to the southern parts. Maximum annual rainfall is noticed at Dharmasala (3400 mm) in Kangra district whereas, areas near Indo-Tibetan border are arid, dusty with heavy snow fall and are covered with snow nearly fromDecember to May. The temperature also varies throughout the state.

Water Resources: Himachal Pradesh provides water to both the Indus and Ganges basins. The major river systems of the region are the Chandrabhaga or the Chenab, the Ravi, the Beas, the Sutlej and the Yamuna. The river Beas originates from ‘Vyas Kund’, the Pir Panjal range near Rohtang Pass and flows some 256 km in Himachal Pradesh. Apart from these, Baspa, Paber, Giri, Gambhar etc., are some other important rivers which ultimately join the main rivers. These perennial rivers are fed by snow and rainfall and are protected by a fairly extensive cover of natural vegetation.

Vegetation/Forest: Himachal Pradesh with its undulating topography, varying degrees of altitudes ranging from 300 m to nearly 7000 m, subtropical to subarctic climate has diverse and rich vegetation from tropical deciduous to alpine meadows and cold deserts. The Recorded Forest Area (RFA) in Himachal Pradesh is 37,033 sq. km, out of which 1,898 sq. km is reserve forest, 33,130 sq. km is protected forest and 2,005 sq. km is unclassed forests. Forests in this state currently cover an area of nearly 37,939 sq. km, which is about 68.16% of the total land area of the state. The state is among the most heavily forested Indian states with 38.9% of the area as forest land, but this is no reason for complacency as the growth of apple orchards and potato farms, the building of roads and the felling of trees are all taking its toll on the forested land. The vegetation of this state can be broadly classified into: i) tropical (below 1000 m), ii) subtropical (between 1800–2000 m), iii) temperate (between 1800–

3500 m), iv) subalpine (between 3500–4000 m) and v) alpine (above 4000 m).

The common floral elements of tropical vegetation in the state are: Albizia procera, Anogeissus latifolia, Buchanania lanzan, Dendrocalamus strictus, Grewia optiva, Holoptelea integrifolia, Mallotus philippensis, Murraya koenigii, Nyctanthes arbor-tristis, Phanera vahlii, Shorea robusta, Toona ciliata and Woodfordia fruticosa. Some common constituents of subtropical vegetation are: Acacia catechu, Chrysopogon spp., Euphorbia royleana, Olea cuspidata, Pinus roxburghii, Punica granatum, Rhododendron arboreum, Rhus semialata, Rubus ellipticus, Saccharum spp., Themeda spp., Terminalia chebula and Zanthoxylum alatum. Some common floral elements of temperate vegetation are Adhatoda zeylanica, Betula alnoides, Betula utilis, Capparis spinosa, Cedrus deodara, Colebrookea oppositifolia, Dalbergia sissoo, Fragaria vesca, Haldina cordifolia, Hedera nepalensis, Litsea umbrosa, Lonicera angustifolia, Pinus gerardiana, Quercus incana, Rosa macrophylla and Rhododendron arboreum, etc. Subalpine vegetation constitutes Anemone spp., Berberis spp., Betula utilis, Cotoneaster spp., Gentiana spp., Geranium spp., Juniperus communis, Pedicularis spp., Ranunculus spp., Rosa spp. and species Rhododendron like R. anthopogon, R. campanulatum and R. lepidotum. Lastly the floral elements of Alpine vegetation are Androsace spp., Dactylorhiza hatagirea, Meconopsis spp., Gentiana spp., Polygonum spp., Primula spp., Rhododendron anthopogon, Rumex spp. and Saxifraga spp.

Plant Diversity: The state harbours a total of 2,571 species under 1038 genera belonging to 180 families of flowering plants (Chowdhery, 1999). Of these, 1890 species in 821 genera and 153 families belongs to dicotyledons and 681 species in 217 genera and 27 families belongs to monocotyledons. Asteraceae with 328 species are the largest family in the state followed by Poaceae (321 spp.), Leguminosae (278 spp.), Rosaceae (157 spp.), Scrophulariaceae (138 spp.), Lamiaceae (136 spp.), Cyperaceae (125 spp.), Ranunculaceae (116 spp.), Apiaceae (92 spp.) and Brassicaceae (83 spp.), whereas among the genera, Carex (48 spp.) is the largest genus followed by Polygonum (37 spp.), Poa (33 spp.), Gentiana (28 spp.), Epilobium (26 spp.), Pedicularis (26 spp.), Cotoneaster (25 spp.), Saussurea (25 spp.), Cyperus (23 spp.) and Euphorbia (23 spp.).

Endemic and Rare Plants: A large number of endemic taxa found in Himachal Pradesh are Agropyron schugnanicum (Poaceae), Anaphalis himachalensis (Asteraceae), Aquilegia nivalis (Ranunculaceae), Astragalus grahamianus (Fabaceae), Christolea stewartii (Brassicaceae), Deyeuxia simlensis (Poaceae), Euphrasia jaeschkei (Scrophulariaceae), Ferula jaeschkeana (Apiaceae), Juncus rohtangensis (Juncaceae), Lagotis kunawurensis (Scrophulariaceae), Meconopsis bikramii (Papaveraceae), Poa lahulensis (Poaceae), Pseudomertensia lahulensis (Boraginaceae), Saussurea atkinsonii (Asteraceae), Silene eduardi (Caryophyllaceae), Tanacetum himachalensis (Asteraceae), Viola jangiensis (Violaceae) and Trigonella upendrae (Fabaceae). Some of the rare flowering plant taxa in the state are: Aconitum heterophyllum, Anemone tetrasepala, Arnebia euchroma, Dactylorhiza hatagirea, Ephedra gerardiana, Ferula jaeschkeana, Hyoscyamus niger, Limosella aquatica, Mahonia jaunsarensis, Nardostachys jatamansi, Picrorrhiza kurroa, Podophyllum hexandrum, Primula schlagintweitiana, Saussurea obvallata, Valeriana jaeschkii and Waldheimia stoliczkae.

Forest Resources: In Himachal Pradesh, the local population consumes a large number of wild plants as edible fruits, vegetables, medicines, etc. which are directly collected from the forest. Some of the important groups of wild useful plants are wild edible plants, medicinal and aromatic plants, oil yielding plants, gum and resin yielding plants, dye yielding plants, timber yielding plants, fodder plants, incense and perfume yielding plants, wild ornamental plants, plants of religious belief and plants of botanical curiosities.

Tribal Population: This state has a large area under tribal belt which covers two districts of Lahaul & Spiti and Kinnaur alongwith Bharmaur & Pangi Development blocks of Chamba district. Geographically about half of the area of the state is covered under tribal belt whereas the population here is just 2.2 lakhs i.e. 4.2 percent of the total population of the state (1991). Gaddi, Gujjar, Jad, Bhot, Kinnaura, Lahaula, Pangwala, Swangla are the major tribal communities in the state.

Protected Areas: The state has five National Parks and 32 Wildlife Sanctuaries, together covering a total forest area of 37,939 sq. km and constitutes 68.16% forest area to total geographical area of the state. The state has five National Parks (NP) i.e. Great Himalayan NP (754 sq. km), Inderkilla NP (104 sq. km), Khirganga NP (710 sq. km), Pin Valley (675 sq. km) and Sibalbara NP (19.03 sq. km).

Botanical History: The earliest attempt to collect plants from Himachal Pradesh was made by William Moorcroft (1765–1825) who collected plants from Kangra, Kulu, Lahul and Spiti in 1821. The countess of Dalhousie was the first to collect plants from Shimla in 1829. She collected about 600 species between April and October. J.R. Royal (1800–1858) made extensive collections in Bashahr, Kinnaur and Shimla around 1830. Victor Jacquemont (1801–1832), a French botanist visited the regions of Kinnaur and Spiti on the borders of Tibet and Shimla in 1830 and in the same year R. Inglis also collected plants from Himachal Pradesh. Others who collected in and around Shimla were Col. Munro (1818–1880), Lt. Col. Edward  Madden (1805–1856), J.E. Winterbottom (1803–1854), Richard Strachey (1817–1908). Lord William Hay and Lance collected plants from different places of Himachal Pradesh. R.S. Simpson made collections from Shimla in 1847 and in the same year William Hawtayne Parish made collections from Mandi and Kulu. Sir Henry Collett collected plants from Shimla and adjacent areas in 1885. J.S. Gamble made vast collection from Shimla and its neighbouring areas in 1877. In 1881, D. Brandis made collections from Bashahr and other areas, J.F. Duthie (1845–1922) made collection trips to different places of Himachal in 1892 and 1893. J.H. Lace and G.A. Gammie made collections from Chamba and adjacent areas from 1891-1896. R.N. Parker made extensive collections from Kulu, Bashahr from 1919–1936, in 1934, Parkinson made collections from Parbatti valley and other areas of Himachal Pradesh and in the same period Walter Koelz and Rupchand Thakur also made collections from different places of Himachal Pradesh. N.L. Bor made extensive collections from Lahaul and adjacent areas in 1941. Among other collectors from this area were S.P. Sethi, M.V. Laurie, C.R. Brown, G.S. Puri and M.B. Raizada in the 1900th century. In 1950, S.K. Jain made collections from Parbati valley in 1950.

Threats to the Biodiversity: The cause of threat to the nature and its resources are almost similar all over the world in the form of natural and man-made causes. Floods, soil erosion, landslides, earthquakes, natural competition between the species, biology of species mainly the pollination in the absence of suitable pollinator, natural regeneration, diseases and extension of the alien weedy elements etc. are some of the major natural causes responsible for the destruction of the natural vegetation. The major man-made causes are: population explosion, timber for building purposes, furniture, fuel wood, grazing and fodder, forest fires, exploitation of economically important plant species, development activities and agriculture.

Dicotyledonous plants

Monocotyledonous plants