Vegetation is one of the most valuable gifts to earth. Nature has provided all basic and essential necessities of the humans mainly in the form of food, fodder, fuel, medicine, timber, resins and oils etc. (Gaur, 1999) In Himalayan region communities highly depend on forest and forest resources as green fodder, fuel wood, medicinal plant and timber (Singh and Singh 1987). People of the region largely depend upon a variety of ecosystem goods and services emanating from these forest ecosystems for their subsistence living (Negi 2022). The rich diversity of Central Himalayan forests harbors over 675 wild plant species used by people as food/edible (Negi 2022). At global level a wide diversity of people of the world depends on natural vegetation for their day-to-day needs and sustenance (Rana and Samant, 2011). According to the floral statistics of India (BSI, Kolkata 2019), a total of 2, 68,600 flowering plants of which 6.95% exist in India. The Himalayan range is home of  unique endemic and therapeutic plants, but now days traditional wisdom is depleting due to increasing anthropogenic pressure (Tiwari et al., 2020).  Rapid loss of this rich traditional knowledge is also associated with mass deforestation, migration and over exploitation.  Hence, there is a serious need for proper documentation of indigenous knowledge. Detailed documentation of ethnobotanical study is necessary for conserving traditional knowledge.

Study area

Pithoragarh district is the easternmost Himalayan district in Uttarakhand state. The district lies between 29.4° to 30.3° North latitude and 80° to 81° East longitude along the eastern and southern part of the central Himalayas. A Total 23 village of Pithoragarh and Gangolihat Bagsil, Jajurali, Sanghar, Bans Maitoli, Budali, Sinchaura, Nakote, Majhera, Kante, Halpati , Digtoli, Gurangchaur, Bhandarigaon, Chitgal, Pali, Rawal gaon, Jajut, Pokhari, Simalkote, Kothera,Bayal pani, Balakuncha, Rankot, Agrun was surveyed during study. Temperature range between 0- 40°C durinthe coldest month of January, an average monthly temperature between 0°C to 6°C. By the March the temperature begins to rise progressively till early June which is the hottest month (35 to 40°C) in valley area. Pithoragarh district is ecologically very rich with diversified flora and fauna. The flora of the district includes many Bryophytes, Pteridophytes, Gymnosperms and Angiosperms. Rare varieties of Orchids are also present in the high altitude (Champion and Seth, 1968). The river valleys are dominated by Sal forests, while increasing elevation Chir pine replaces the Sal forests followed by Quercus leucotrichophora A. Camus (Banj) and Deodar forest in the upper ridges of the study area

Methodology

Several intensive field surveys were conducted from March 2018 to September 2020. A total of 312 people were interviewed including 28 Vaidh (traditional healers) and 284 villagers. Interviews were conducted at village and in forest using semi structured questionnaires (Philips and Gentry 1993, Bargali et al., 2007, Padaliya et al., 2015) with participant members of different ages (23–87 years). For use value calculation method of Philips and Gentry (1993) followed.  The informants with knowledge about plants were questioned during the interviews for the local names of the plants, use, available season, spiritual beliefs, harvesting season, utilized parts, drug preparation methods etc. Information gathered by two methods viz. (1) walk in wood method in this case local name and use of plant in field were asked (2) information about ethnobotanical use of plant were collected by with the help of questionnaire. 

Use value of species calculated by following formula-

Use value of each species s for each informant i UVis define as   UVis= ?Uis/ nis

Uis equal the number of uses mentioned in each event by informant I nis equal the number   of events for species s with informant i.

Overall use value for each species s, UVs is then-

UVis= ?iUVis /ns

ns=

equal no of informants interviewed for species s 

 Family use-value (FUV) The significance of plant families can be compared by estimating the FUV. FUV was calculated using the following formula:

FUV = ?UVf /nt

Where UVf is the use-values for all the species within a given family and nt is the total number of species within a given family.

RESULTS AND DISCUSSION

 A total sum of 255 species belonging to 85 families was recorded ethnobotanically important from present study area. These species distributed in different life forms, i.e., trees (53 species), shrubs (66 species), herbs (136 species). Among families, Poaceae (23 species) represented as the dominant family followed by Fabaceae (20 species), Asteraceae (19 species), Lamiaceae (14 species), Rosaceae (11 species), Moraceae (8 species), Acanthaceae (7 species), Urticaceae (7 species) Lauraceae (5 species) and Anacardiaceae (4 species). A total 312 (127 female and 187 male) people were interviewed including 28 Vaidh and 284 villagers. A detail example of calculating use value was illustrated in Table 1.1- it explains the technique with typical example of Quercus leucotrichophora A. Camus (Fagaceae) it shows data from 3 events with one informant. the number of uses are sum-up  for each event and each use is averaged across event. The mean value was transferred to table 1.2. Table 1.2 listed the use value of Quercus leucotrichophora for each 5 informant interviewed, by category and by total.

Table no.1 Uses of  Quercus leucotrichophora mentioned in 3 separate  events

Table no. 2- Use value of Quercus leucotrichophora

Abbreviations used: Fu= Fuel wood Fo= Fodder, M= Medicinal, Ti= Timber, Ed= Edible, Or= Ornamental use, Mn= manure/ Fertilizer, Se= Sacred, To= Tool, Be= Cattle bedding Fe= Fencing, Ot= Other Thus  the Use value (UVis) of Quercus leucotrichophora is 2.11 . Use value generally give us idea about the pressure on species, species have high use value show more pressure or multipurpose used by community. In present example Quercus leucotrichophora  used in 7 category by community indicated high use value. Use value of total 255 plants was calculated (table 3). Different uses of species were categorized in 12 broad categories these were fuel wood, fodder, medicinal, timber, edible, ornamental, fertilizer, sacred, agriculture tool, cattle bedding, Fencing, and other. In present study 165 species were used as fodder, 56 as fuel wood, 129 used as medicinal, 22 as timber, 43 as edible, 8 as ornamental, 3 as fiber,13 as sacred, 26 as agriculture tool, 8 as fencing, 10 as cattle bedding  and 6 species were used miscellaneously (Figure 2). The plant parts used ethno-botanically were leaves (44%), whole plant  (24%), Fruit (6%), seeds (5%), flowers (5%) roots (5%), barks (4%), seed (4%), Rhizome (4%) , Bulbs (2%) and wood/latex (1?ch) (Figure 3).

Figure-  2  Distribution of species in different use category

Figure 3 - Graphical representation of plant parts used

Abbreviations Used- C- Climber; H- Herb; S- Shrub; T- Tree; Ap- Aerial part, AR- altitudinal range,  part, Bl- Bulbs; Br- Barks; Fl- Flowers; Fr- Fruits; Lt- Latex; Lv- Leaves; Rh- Rhizomes, Rs- Resin; Rt- Roots; Sd- Seeds, St- Stems; Tb- Tubers; Wd- Wood; WP- Whole plant

Use value of plants ranged from 0.10 to 2.25 it was divided into three categories viz.  high use value (1.5-2.25) medium use value (0.85-1.5) and low use value (0.10-0.85) . Plants having high use value showed huge pressure because people used them very strongly for different purpose. A total 18 plant fall under high use value Aegle marmelos,  Quercus leucotrichophora Diploknema butyracea, Cedrus deodara, Boehmeria rugulosa, Dendrocalamus strictus,Mallotus philippensis, Emblica officinalis, Celtis australis, Ougeinia oojeinensis, Pinus roxburghii, Zanthoxylum armatum, Melia azedarach, Rhododendron arboretum, Grewia oppositifolia, Syzygium cumini,  Terminalia chebula, Quercus glauca, 46 plants were reported to moderate use value Terminalia bellirica , Prunus cerasoides, Shorea robusta, Berberis aristata, Toona ciliata, Tinospora cordifolia, Ficus auriculata, Ficus semicordata, Berberis asiatica, Pyrus pashia , Bombax ceiba, Cupressus torulosa, Xylosma longifolia, Acer oblongum, Semecarpus anacardium, Ilex dipyrena, Carpinus viminea, Albizia lebbeck, Swertia chirayita, Vitex negundo, Litsea monopetala, Malaxis acuminata, Bischofia javanica, Glochidion velutinum, Arundinella nepalensis , Cynodon dactylon, Rosa brunonii, Rubia cordifolia, Bergenia ciliata, Symplocos paniculate Debregeasia longifolia, Rhus cotinus, Bauhinia variegata, Cinnamomum tamala, Ficus palmata, Aesculus indica, Alnus nepalensis, Anogeissus latifolia ,Viburnum mullaha and 191 plants under moderate use value. Among familes Sapotaceae Fagaceae Pinaceae Cannabaceae Myrtaceae Meliaceae Dryopteridaceae and Combretaceae depicted high family use value. Table 3 depicted the comparison of present findings with studies in West Himalaya According to Uttarakhand Medicinal Plants Database, 1127 species belonging to 153 families used medicinally. Pandey et al., (2017) documented plant species for different disorders, such as 14 species for jaundice, diarrhoea (12 species), and dysentery (16 species).  Kala (2020) documented 82 plant species used to treat seven types of respiratory diseases such as asthma, bronchitis, tuberculosis, pneumonia, influenza, lung disorder, and cough and cold. Ojha et al., (2020) recorded 70 species belonging to 64 genera and 35 families for curing various human ailments by the local community, of which 21 species were used most extensively in the traditional health care system. Tiwari et al., (2020) reported 56 plant species belonging to 34 families ethnobotanically important from Kumaun Himalaya

Table 2- Ethnobotanical studies carried out in the Uttarakhand, Western Himalaya

Rautela and Tiwari (2021) documented a total of 113 weed species belonging to 90 genera and 38 families having various folk uses in Rudraprayag.