Vegetation

Nepal is a small country — about 147,181 km², a little over a tenth of one per cent of the Earth's land — yet it holds about 3.2 % of the world's known flora. The reason is height. In a north–south line barely 193 km long the land climbs from 59 m in the Terai to 8,848.86 m at Sagarmatha, and every thousand metres of that climb cools the air by roughly 6 °C. A traveller walking from Birgunj to the Khumbu passes through as many vegetation belts as a traveller walking from India to the Arctic. This unit maps those belts, names the trees that mark them, and asks what Nepal is doing to keep them.

5.1 Vegetation

What decides the vegetation of a place

Four controls do nearly all the work in Nepal:

1. Altitude. Temperature falls about 6 °C for every 1,000 m of climb. This single fact produces the belts described below.
2. Rainfall and the monsoon. Nepal averages about 1,600 mm of rain a year and roughly 80 % of it falls between June and September. The east is wetter than the west — Taplejung gets about 2,000 mm, Baitadi about 1,000 mm — so eastern forests are evergreen and dense where western forests of the same altitude are drier and more open. The wettest station, Lumle in Kaski, records about 5,550 mm; Jomsom in Mustang, in the rain shadow behind the Annapurnas, records under 300 mm.
3. Aspect — which way a slope faces. South-facing slopes are hot and dry and carry chir pine (Pinus roxburghii) and Quercus semecarpifolia; north-facing slopes at the same height are cool and moist and carry laurels, firs and rhododendrons.
4. Soil and landform. Fresh river gravel carries khair and sissoo; the older, well-drained alluvium behind it carries Sal.

The vegetation zones of Nepal

Zone	Altitude	Forest type and indicator species	Where in Nepal
Tropical	below 1000 m	Sal forest — Shorea robusta (sal), with Terminalia alata (saj), Anogeissus latifolia, Mallotus philippensis; khair–sissoo riverine forest — Acacia catechu (khayar) and Dalbergia sissoo (sissau) on fresh river gravel; Bombax ceiba (simal) savanna; khar-patter grassland of Saccharum spontaneum; tropical evergreen forest of Michelia champaca (chanp) in the east	Terai, Bhabar, inner Terai (Dun) valleys and Chure slopes — Jhapa to Kanchanpur; Chitwan, Bardiya, Shuklaphanta, Banke, Parsa, Koshi Tappu
Subtropical	1000–2000 m	Schima–Castanopsis forest — Schima wallichii (chilaune) with Castanopsis indica (dhalne katus); chir pine forest — Pinus roxburghii (khote salla) on dry south-facing slopes; Alnus nepalensis (utis), a pioneer on landslides and stream banks	Mahabharat midlands — Kathmandu valley rim, Kavre, Dhading, Tanahun, Palpa, Surkhet, Dhankuta, Ilam; Shivapuri Nagarjun NP
Temperate	2000–3000 m	Oak–rhododendron forest — Quercus semecarpifolia (khasru), Q. lamellosa, with Rhododendron arboreum (lali gurans); conifers Pinus wallichiana (gobre salla), Tsuga dumosa (thingre salla), and in the far west Cedrus deodara (devdar); Acer and Juglans regia (okhar) on moist slopes	Ghorepani and Ghandruk in ACA, Rara NP, Khaptad NP, Langtang, Ilam and Taplejung
Subalpine	3000–4000 m	Fir–birch forest — Abies spectabilis (talispatra, Himalayan silver fir) with Rhododendron campanulatum (nilo chimal) beneath; birch Betula utilis (bhojpatra) in near-pure belts up to the tree line; Juniperus recurva (dhupi) in dry inner valleys	Sagarmatha NP, Langtang NP, Makalu Barun, Manaslu and Kanchenjunga CAs, Dhorpatan
Alpine	4000–5000 m	Treeless. Alpine scrub of Rhododendron anthopogon (sunpati) and Juniperus indica; above it alpine meadow (kharka, patan) of Kobresia and Carex sedges with Primula, Gentiana and Meconopsis; the medicinal belt of yarsagumba, jatamansi, panchaunle and kutki	High Himal of all northern districts — Solukhumbu, Rasuwa, Manang, Mustang, Dolpa, Humla, Darchula
Nival (Arctic)	above 5000 m	Permanent snow, rock and glacier. Only mosses, lichens and cushion plants such as Stellaria decumbens, recorded as high as about 6,100 m	Above the snow line everywhere; Sagarmatha, Kanchenjunga, Api Nampa

Behind the Himalayan wall lies a seventh kind of country. Upper Mustang, Manang, Dolpa and Humla lie in the rain shadow and receive only about 250 mm of rain a year — less than a tenth of Pokhara. The vegetation there is trans-Himalayan steppe, or cold desert: thorny cushion shrubs of Caragana and Lonicera spinosa, Artemisia, Ephedra gerardiana, with Hippophae (sea buckthorn) and willows along the streams and Juniperus indica on the better-watered slopes. Ground cover is thin and bare gravel is everywhere.

The flora of Nepal in numbers

Group	Species recorded in Nepal
Flowering plants (angiosperms)	about 5,600
Gymnosperms	26
Pteridophytes (ferns and allies)	583
Bryophytes	1,217
Lichens	1,086
Fungi	2,470
Algae	1,101
Endemic flowering plants (found nowhere else)	348

Figures: Department of Plant Resources, 2025. Orchidaceae is the largest family, with about 500 orchid species; Nepal has roughly 30 species of Rhododendron, of which Rhododendron arboreum (lali gurans) is the national flower. Forest covers 43.4 % of the country, and forest together with other wooded land covers 46.1 % (Forest Research and Training Centre, 2024) — second only to Bhutan in South Asia.

In-situ conservation

In-situ conservation is the stronger method, because it saves not one species but the whole community it belongs to, and the species keeps evolving in the conditions it is adapted to. Nepal's legal instrument is the National Parks and Wildlife Conservation Act, 1973 (2029 BS), which created the first protected area, Chitwan National Park, in 1973.

Category	Number	Examples and notes
National parks	13	Chitwan (1973, the first, and a natural World Heritage Site since 1984); Sagarmatha (1976, World Heritage 1979); Langtang; Rara (106 km², the smallest); Shey Phoksundo (the largest park); Khaptad; Bardiya; Makalu Barun; Shivapuri Nagarjun; Banke (2010); Shuklaphanta and Parsa (upgraded from reserves in 2017); Chhayanath, Mugu (2025)
Wildlife reserve	1	Koshi Tappu (1976), Sunsari–Saptari–Udayapur — the last home of the wild buffalo (arna)
Hunting reserve	1	Dhorpatan (1987), Baglung–Myagdi–Rukum — the only reserve where licensed hunting is allowed
Conservation areas	6	Annapurna (1992; 7,629 km², the largest protected area in Nepal), Kanchenjunga, Manaslu, Gaurishankar, Api Nampa, and Krishnasar (Blackbuck) in Bardiya — at 16.95 km² the smallest
Buffer zones	13	Declared around parks and reserves; 30–50 % of the park's income is returned to buffer-zone communities
Ramsar (wetland) sites	10	Koshi Tappu (1987, the first), Beeshazari Tal, Ghodaghodi Tal, Jagdishpur reservoir, Rara, Phoksundo, Gosaikunda, Gokyo, Mai Pokhari, and the Lake Cluster of Pokhara Valley (2016, the largest)

Together the protected areas cover about 34,420 km², roughly 23.4 % of Nepal's land area — one of the highest proportions in Asia. Outside them, community forestry does the same work by another route: about 23,000 community forest user groups (CFUGs) manage some 2.5 million hectares, close to 39 % of the national forest, on behalf of more than three million households. Religious forests, leasehold forests for poor households, and the sacred groves around temples and deurali resting places add to the total.

Ex-situ conservation

Ex-situ methods are the back-up. They matter most for species already too rare to survive in the wild, for crop varieties that farmers have stopped growing, and for keeping material available to researchers and breeders.

Facility	Where	What it conserves
National Botanical Garden (est. 1962, 82 ha)	Godawari, Lalitpur	Over 1,285 living plant species in about 30 themed gardens; one of 11 botanical gardens run by the Department of Plant Resources, from Ilam in the east to Kailali in the west
National Herbarium and Plant Laboratories (KATH) (est. 1961)	Godawari, Lalitpur	About 170,000 dried, mounted and named herbarium specimens — the reference collection against which any Nepali plant is identified
National Gene Bank — National Agriculture Genetic Resources Centre, NARC (est. 2010)	Khumaltar, Lalitpur	About 11,800 seed accessions of more than 330 crop species stored at −20 °C, plus a field gene bank, an in-vitro (tissue-culture) bank and a DNA bank
Community seed banks (first at Dalchowki, Lalitpur, 1994)	About 54 across the country	Local landraces of rice, maize, millet and beans, kept and exchanged by farmers themselves
Central Zoo (est. 1932, about 6 ha; run by NTNC since 1995)	Jawalakhel, Lalitpur	Nepal's only zoo — roughly 1,300 animals of about 120 species, and a rescue centre
Gharial Breeding Centre (est. 1978)	Kasara, Chitwan	Captive breeding of the gharial crocodile; over 1,800 juveniles released into Nepal's rivers

Answering "differentiate in-situ and ex-situ conservation"

Draw a two-column table and fill four rows: (i) where the organism is kept; (ii) whether the whole ecosystem is conserved; (iii) whether evolution continues; (iv) cost and number of individuals possible. Then give two named Nepali examples of each. A pair of examples is usually worth a mark on its own.

5.2 Natural environment, vegetation and human activities

Vegetation sits between the physical environment and the people who live in it, and the influence runs in all three directions.

What people take from vegetation

Firewood is still the main cooking fuel in most rural Nepali households. Forests also supply timber, fodder for stall-fed cattle, leaf litter that becomes compost for the fields, bamboo, and non-timber forest products (NTFPs) — Swertia chirayita (chiraito), Nardostachys jatamansi (jatamansi), Zanthoxylum armatum (timur), Cinnamomum tamala (tejpat) and yarsagumba, which together earn rural households a large cash income. Beyond the products, vegetation holds soil on steep slopes, slows monsoon runoff, recharges springs, stores carbon, and brings the trekkers whose money supports whole districts.

How human activities damage vegetation

Activity	What it does
Deforestation and encroachment	Clearing for settlement, roads and cropland; worst in the Terai and inner Terai after malaria control opened them to settlement in the 1950s and 60s
Shifting cultivation (khoriya)	Slash-and-burn on hill slopes in the east; the fallow period is now too short for the forest to recover
Overgrazing	Too many cattle, goats and sheep on the same pasture; seedlings are eaten before they can establish, and alpine meadows are worn to bare soil
Forest fire	Deliberate pre-monsoon burning (March–May) to bring on fresh grass; it kills regeneration and dries the soil
Lopping and illegal felling	Repeated lopping of Sal and oak for fodder and fuel leaves stunted, hollow trees
Over-collection of NTFPs	Yarsagumba, panchaunle and jatamansi are dug up before they can set seed
Quarrying and road building in the Chure	Sand, gravel and boulder extraction destabilises the Chure, which is the recharge zone for Terai groundwater
Invasive alien species	Mikania micrantha smothers Sal regeneration in Chitwan; Eichhornia crassipes (water hyacinth) blankets Phewa Tal; Lantana camara, Chromolaena odorata and Parthenium hysterophorus take over grazing land
Pollution and infrastructure	Brick kilns, cement dust, hydropower reservoirs and transmission lines

The consequences are visible: soil erosion and landslides, sheet flooding when the Chure rivers spill onto the Terai, a falling Terai water table, the loss of species before they are even described, and an upward shift of the tree line as the climate warms.

What is being done

• Community forestry — handing national forest to local user groups. Forest cover in the mid-hills has increased measurably since the 1990s, the clearest conservation success Nepal has had.
• Leasehold forestry for poor households, and agroforestry — growing fodder and fruit trees on private land so that pressure on the forest falls.
• Protected areas and buffer zones, with revenue sharing so that local people gain from conservation rather than lose by it.
• The President Chure–Terai Madhesh Conservation Programme, which bans riverbed mining in sensitive stretches and restores degraded Chure catchments.
• Alternative energy — biogas plants, improved cooking stoves, micro-hydro and LPG reduce firewood demand.
• Law. The Forest Act, 2019 (2076 BS) protects named species. Two are banned outright from collection, sale, transport and export — Dactylorhiza hatagirea (panchaunle) and the bark of Juglans regia (okhar). Seven, including Abies spectabilis, Nardostachys jatamansi, Taxus spp. and Rauvolfia serpentina, may not be exported unprocessed. Four trees — Shorea robusta, Dalbergia latifolia (satisal), Pterocarpus marsupium (bijayasal) and Juglans regia — may not be felled or transported for commercial purposes.

Chapter summary

• Vegetation is the plant cover of an area; flora is the list of species in it. Nepal holds about 3.2 % of world flora on under 0.1 % of world land.
• Temperature falls about 6 °C per 1000 m, which produces six altitudinal zones: Tropical (<1000 m, Sal), Subtropical (1000–2000 m, chilaune–katus and chir pine), Temperate (2000–3000 m, oak and rhododendron), Subalpine (3000–4000 m, fir and birch), Alpine (4000–5000 m, scrub and meadow) and Nival (>5000 m, snow).
• The tree line lies near 4000 m. Behind the Himalaya, the trans-Himalayan steppe of Mustang, Manang and Dolpa gets only about 250 mm of rain and carries Caragana, Artemisia and Hippophae.
• In-situ conservation protects the habitat: 13 national parks, 1 wildlife reserve (Koshi Tappu), 1 hunting reserve (Dhorpatan), 6 conservation areas, 13 buffer zones and 10 Ramsar sites — about 23.4 % of the country. Chitwan (1973) was the first; Annapurna (1992) is the largest.
• Ex-situ conservation protects the organism away from its habitat: the National Botanical Garden at Godawari (1962), the National Herbarium (KATH), the National Gene Bank at Khumaltar (2010), community seed banks, and the Central Zoo, Jawalakhel (1932).
• About 23,000 CFUGs manage 2.5 million ha, nearly 39 % of Nepal's forest. Forest covers 43.4 % of the country.
• Vegetation is damaged by deforestation, khoriya, overgrazing, fire, over-collection of NTFPs, Chure quarrying and invasive species such as Mikania micrantha and Eichhornia crassipes; it is repaired by community forestry, agroforestry, buffer-zone sharing, alternative energy and the Forest Act, 2019.

Practice questions

Group A — Multiple choice (1 mark each)

1. The altitudinal range of the temperate vegetation zone of Nepal is [1]abelow 1000 mb1000–2000 mc2000–3000 md3000–4000 m
2. Shorea robusta is the dominant tree of the [1]atropical zonebsubtropical zonectemperate zonedsubalpine zone
3. The first national park of Nepal, established in 1973, is [1]aSagarmathabLangtangcChitwandRara
4. The National Gene Bank of Nepal is located at [1]aGodawaribKhumaltarcJawalakheldKasara
5. Betula utilis (bhojpatra) is characteristic of the [1]atropical zonebtemperate zonecsubalpine zonednival zone
6. Conservation of a species in a botanical garden is an example of [1]ain-situ conservationbex-situ conservationcbuffer zone managementdcommunity forestry

Answers to Group A

1. (c) — the temperate belt runs from 2000 m to 3000 m, the oak–rhododendron zone.

2. (a) — Sal is the dominant tree of the Terai, Bhabar and Dun valleys, below 1000 m.

3. (c) — Chitwan, 1973; Sagarmatha, Langtang and Rara followed in 1976.

4. (b) — the National Agriculture Genetic Resources Centre, NARC, Khumaltar, Lalitpur.

5. (c) — Himalayan birch forms near-pure belts from about 3300 m to the tree line.

6. (b) — the plant is kept outside its natural habitat, so it is ex-situ.

Group B — Short answer (4 marks each)

1. Name the six altitudinal vegetation zones of Nepal with their altitude ranges, and give one indicator species of each. [4]
2. Differentiate between in-situ and ex-situ conservation, giving two named Nepali examples of each. [4]
3. The mean annual temperature at Pokhara (altitude 820 m) is 20 °C. Using a lapse rate of 6 °C per 1000 m, estimate the temperature at Ghorepani (2,870 m), and name the vegetation zone and the indicator tree species you would expect to find there. [4]
4. List any four human activities that degrade the vegetation of Nepal, and state one control measure for each. [4]

Answers to Group B

1. Tropical, below 1000 m — Shorea robusta. Subtropical, 1000–2000 m — Schima wallichii or Pinus roxburghii. Temperate, 2000–3000 m — Quercus semecarpifolia or Rhododendron arboreum. Subalpine, 3000–4000 m — Abies spectabilis or Betula utilis. Alpine, 4000–5000 m — Rhododendron anthopogon with Kobresia meadow. Nival, above 5000 m — mosses and lichens only.

2. In-situ = conserved inside the natural habitat, so the whole ecosystem is saved and the species keeps evolving; cheap per species but needs large areas. Examples: Chitwan National Park, Koshi Tappu Wildlife Reserve. Ex-situ = conserved outside the natural habitat, under human care; useful for species too rare to survive in the wild, but expensive and only a few individuals can be held. Examples: National Botanical Garden, Godawari; National Gene Bank, Khumaltar (or the Central Zoo, Jawalakhel).

3. Height gained = 2870 - 820 = 2050\ \text{m}. Temperature fall = 6 \times 2050/1000 = 12.3\ ^\circ\text{C}, so T = 20 - 12.3 = 7.7\ ^\circ\text{C}. At 2,870 m Ghorepani lies in the temperate zone, where the expected species are Quercus semecarpifolia (khasru), Rhododendron arboreum (lali gurans) and Pinus wallichiana (gobre salla).

4. (i) Deforestation and encroachment — hand the forest to community forest user groups and register boundaries. (ii) Overgrazing — fix a stocking limit and rotate the kharka, and promote stall feeding on fodder trees. (iii) Forest fire — build fire lines, train community fire-fighting groups and ban pre-monsoon burning. (iv) Over-collection of NTFPs such as yarsagumba — issue harvesting permits with a closed season, and cultivate the species instead of digging it from the wild. (A fifth: invasive species such as Mikania micrantha — manual uprooting before flowering and replanting with native species.)

Group C — Long answer (8 marks each)

1. Describe the types of vegetation found in Nepal from the Terai to the snow line, with a labelled diagram showing altitude, and explain why so many vegetation types occur in such a small country. [8]
2. (a) Define in-situ and ex-situ conservation. [2](b) Describe the protected area system of Nepal, naming the categories, their numbers and one example of each. [4](c) Describe any two ex-situ conservation facilities of Nepal, stating where each is and what it conserves. [2]

Answer outline to Group C question 1

Diagram: the altitude profile of this chapter — a rising transect from Terai to High Himal with horizontal bands at 1000, 2000, 3000, 4000 and 5000 m, each band named and given two indicator species, and the tree line marked at about 4000 m.

Points to make: (i) Tropical below 1000 m — Sal forest of Shorea robusta with Terminalia alata, khair–sissoo riverine forest of Acacia catechu and Dalbergia sissoo, and Saccharum grassland; Terai, Bhabar and Dun valleys. (ii) Subtropical 1000–2000 m — Schima wallichii with Castanopsis indica, chir pine Pinus roxburghii on dry south slopes, Alnus nepalensis on stream banks; the Mahabharat midlands. (iii) Temperate 2000–3000 m — oak Quercus semecarpifolia with Rhododendron arboreum, blue pine Pinus wallichiana, Tsuga dumosa. (iv) Subalpine 3000–4000 m — silver fir Abies spectabilis and birch Betula utilis with Rhododendron campanulatum. (v) Alpine 4000–5000 m — treeless scrub of Rhododendron anthopogon and Juniperus, and Kobresia meadows grazed in summer. (vi) Nival above 5000 m — snow and rock, mosses and lichens only. (vii) The trans-Himalayan cold desert of Mustang, Manang and Dolpa, with about 250 mm of rain, Caragana, Artemisia and Hippophae.

Why so many: the land rises from 59 m to 8,848 m within 193 km, so temperature falls about 6 °C per 1000 m and produces belt after belt; the monsoon makes the east wetter than the west; aspect separates dry south-facing from moist north-facing slopes; and the Himalaya casts a rain shadow that creates a cold desert on its northern side. Nepal therefore carries tropical and arctic vegetation in the same country.