3.8 FLORA, FAUNA AND AVIFAUNA RESERVES
The flora of a region is the vegetation typology of the region. As plants are very specific to environments, the ecologist who knows the presence, pattern and distribution of plants can infer more accurate information about their environment than is generally available from existing information on climate, soil, the water regimen and other factors.
The major vegetation types found in Thimphu Valley are Blue Pine forests, Riparian vegetation, Marshland vegetation and Paddy Fields or Wetlands.
3.8.1 FOREST
Forests are the heart of the mountain ecology and are the prime natural resource
of the country, supporting a variety of plant and wildlife species. Forests
protect the hill slopes from erosion, landslides and also play a major role
in protecting the watersheds of the rivers. Forests play a prime role in maintaining
the climatic conditions. Their annual foliage droppings add compost nutrition
to the soil and enrich the country silently.
Forests are the dominant land cover of the country occupying 72.5 % of the total land, providing food, medicine, timber, waxes, dyes and variety of other products. The forests of Thimphu Valley are classified as temperate forests. Due to relatively less rainfall these forests are dominated by Blue Pine trees (Pinus Wallichiana). These pines regenerate very quickly and invade pastures and orchards. The lower valley slopes are covered with pure Blue Pine forests. Up in high altitudes it mixes with other conifer and oak varieties. The Blue Pine of the Thimphu region is considered as genetically the best in Bhutan. The special feature of these pine trees is that cattle do not graze them. Other common trees are Spruce (Picea Spinulosa) and Oak (Quercu Sgriffithii). These oaks are commonly seen on the slopes of Dechencholing. Quercus Sernecarpifolia is another type of oak found mixed under the Blue Pines. Popular (Populus Ciliata) is normally found in sharp bends along the gullies.
The pine forest on the way to Dechenphu Lhakhang consists of all stories of vegetation (ground covers, shrubs and creepers) and is one of the thickly vegetated forests within the city. The forest near the Dechencholing Palace is the only patch of broad leaf forest in the city. Within the Thimphu region these forests play a major role in protecting the steep, and very steep slope ranges of the valley walls.
Blue Pine forest near Dechencholing
3.8.2 RIPARIAN VEGETATION
The land and the ecosystem supported by the river and streams in its immediate
surroundings is called the Riparian Zone. Riparian vegetation is the vegetation
supported by the Riparian Zone. Most of this vegetation requires moist and
damp soil, and survives in high humid conditions. This river/stream-side vegetation
plays a significant role in protecting the edges and banks of the watercourses
from soil erosion and other river actions.
Riparian vegetation along Dechencholing stream
Dense forest with all stories of vegetation towards Dechenphu Lhakhang
MAP
NO. 3.9 FLORA, AVIFAUNA AND FAUNA PRESERVES(Click to view the map)
3.8.3 MARSHLANDS
Marshlands are wetlands, which act as water severs. Marshlands are the prime
ecosystem of natural systems, supporting a variety of plants and birds. They
play a major role in maintenance of ground water and surface water supplies.
Sediment trapping, water purification, erosion control, pollution abatement
and provision of habitats are other functions of marshlands.
Four decades back Thimphu, Chankhar and Gyatsa valleys were natural forest wetlands. Some patches of these, like the land behind the Swimming Pool Complex, still survive within the city limits. They are at the mercy of inevitable development pressurized by surmounting urban development. Some marshy patches also occur along the river near Babesa, Langjophaka and Taba areas. Most of these marshlands act as habitats for winter migrant birds.
3.8.4 PADDY WETLANDS
Paddy wetlands are terraced and irrigated agriculture lands, Paddy terraces
are found from 2300 meters to 2600 meters elevation within Thimphu Valley.
It is concentrated mostly in the valley floor occupying the Lower and Higher
River Terraces. Thimphu Valley stands next to Paro Valley in terms of rice
yield per hectare. The environmental significance of these paddy fields is
that they protect and manage the fertile Lower River Terraces, which are potential
ground water resources.
Paddy wetlands on the valley floor.
3.8.5 FAUNA AND AVIFAUNA
It is common knowledge that pigeons and mockingbirds associate with man, but
that bear, wildcat, and eagles tend to avoid us. Trout fish like cold water,
bass little warmer, and catfish prefer it warm and muddy. Creatures are specific
to environments and, like plants; their survival is an indication of a healthy
environment. If we can discern different environments, and know the proclivities
of creatures for these, it will be possible to establish the pattern and distribution
of wildlife in the region.
In Thimphu Valley the forest area between Langjophaka and Taba, and the forest areas on the eastern banks of the Wang Chhu act as corridors for Bear and Leopard cats. Just a few years back they were often sighted on the Wang Chhu banks in search of water. Now it is becoming a rare occasion to sight them due to intense human interference.
Thimphu used to be a bird’s paradise with habitats for a variety of bird species. Rapid urbanization has deteriorated these habitats. Still some small patches of marshlands within the city and along the river act as home for Snipes, Wood Cock and Cracks.
The land behind the Swimming Pool Complex is the home for globally endangered Wood Snipe and other snipes, like Common Snipe and Solitary Snipe. The marshlands along the river serve as a highway for the passage of migrant birds like Ferruginous Duck, Tufted Duck, Ruddy Shel Duck, Bar–Headed Goose, Northern Pintail, Common Pochard, Red–Crested Pochard, Black-Tailed Crake, Ruddy–Breasted Crake, Himalayan Kingfisher, Common Kingfisher, Northern Lapwing, Red – Wattled Lapwing, Yellow – Wattled Lapwing, Green Sand Piper, Common Sand Piper and Bronze – Winged Jacana.
Source: Nature Conservation Division and Druk Bija
Yigsel Bhutan Bird Newsletter.
Surface Hydrology
1. The Wang Chhu and its tributaries is the main hydrological unit of the
valley. The river is wild and has created the rich fertile valley floors of
Thimphu over a period of time. The major streams like Chhubar Chhu, Ola Rong
Chhu, Ngabe Rong Chhu, Samteling streams, Taba Streams and Dechencholing streams,
and its tributaries form the major part of the hydrological network.
2. These streams are fed by numerous minor streams/rivulets through the gullies
running down the hill slopes. These streams originate from natural springs
and lakes at higher altitudes.
3. The Alluvial Fans and River Terraces formed by the Wang Chhu and its tributaries
are rich for cultivation.
4. Though there is no detailed mapping of aquifers, aquifer recharges and
ground water tables. The presence of a number of springs along the valley
indicate the presence of ground water flow,
5. The river and streams support a variety of plant species within their Riparian
Zone (The ecosystem in immediate surroundings of the watercourse which is
influenced by it), which protects the edges of streams and river from erosion.
6. Most of the streams that run within the Core area of the city are diverted,
canalized, polluted with domestic sewerage and solid wastes. The river, stream
and springs serve as the major drinking water source for the city.
Issues:
1. The pollution level in the river and streams is far above the drinking
water standards, for e.g. the FC count report by RSPN (2000 Sep - Dec) shows
that most of the samples collected from streams, river and tap water of some
public places and restaurants, are well above the 50cfu/100ml and in most
of the cases it is above the counting limit. The safe limit is 10cfu/100ml.
2. Main cause for the pollution is due to lack of sewage disposal network
which serves only limited areas of the city and lack of public awareness.
The streams within the city limit also act as solid waste disposal sites.
3. The Riparian Zone (The river/stream and its related vegetation) within
the city area is damaged to the maximum due to reckless urbanization, thus
affecting the quality and environment of streams and river .This will also
lead to increased erosion along the river banks.
4. Though it is mentioned in the Forest and Conservation Act of 1995 that
felling of trees is not permitted along the river and streams within 100 feet,
from the edge of the watercourse, this Act is not respected within city limits.
TABLE 3.4: Flora, Fauna and Avifauna Reserves
| S.No | Environmental Classification | Characteristics and Significance | Location | Land Use Suitability |
| 1 | FLORA | |||
| Forests | Forests are the heart of mountain ecology and are
the prime natural resource of the country, supporting variety of species
and also protect the hill slopes from erosion and landslides. These forests
play a major role in protecting the watershed of the rivers and control
the climate of the region. 1. Thimphu Valley falls within temperate zone, covered with Blue Pine forests (Pinus Wallichiama).The pine trees of Thimphu region are considered as genetically the best species in the country. 2. Apart from the pine forests, mixed forests of pine and other coniferous species are found in higher altitudes. 3. The forest near Dechencholing palace of the city has broad leaf forests with Oak trees and other broad leaf varieties 4. The pine forest on the way to Dechenphu Lhakhang have all layers of vegetation and is one of the thickly vegetated forests within the city. |
Forest areas east of Serbithang and Babesa, the forest areas of Simtokha and east of Simtokha towards the Wangdi road on both sides of the valley walls, the forest areas south and west of Chang Bangdu, Changzamtog and Chang Gedaphu area, hill slopes south of Motithang, hill slopes above(east of) Yangchenphug School and surroundings of Tandin Ney Lhakhang, tree cover on the eastern hill slopes above the Lungten Zampa - Langjophaka road, forest area between Langjophaka and Taba, forest area between Zilukha and Dechenphodrang Lhakhang, slopes south of Samteling, slopes above(west of) Jongshina, forest area between Taba and Dechencholing Palace and forest area West of Dechencholing. | Conservation and protection of the existing forests, densification of forest cover with indigenous plants in required areas. | |
| Marshlands | Marshlands support variety of plant species; marshlands in Thimphu valley are mostly found on the riverbanks and along the streams. These marshlands act as habitats for the migrating birds. | 1. The land south of the sewage treatment tank along
the river 2. The land behind the Swimming Pool Complex 3. The land below (east of) Motithang High school 4. The banks of the river and the islands near the cremation ground 5. The bank of the river maintained by Center for Bhutan Studies (CBS) 6. The banks of the river along Taba and Jongshina. |
Conservation and protection of marshlands | |
| Paddy Fields (Wet Lands) | 1. Agriculture is the prime occupation and staple
diet of the country. In spite of the difficult topography, paddy terraces
are found from 150 m to 2800 m. 2. Paddy fields occupy major part of the valley floor area within Thimphu Valley, and they are the fertile and productive lands of the valley. 3. These paddy fields are important not only due to its production, but also for its scenic value. |
Lower Babesa and parts of Wangchutaba, lower Simtokha and Lungtenphu, Hejo, some areas of Langjophaka, Jongshina, lower Taba and Dechencholing. | Agriculture and its related land uses | |
| 2 | FAUNA | |||
| Certain forest areas of Thimphu City act as corridors for wildlife animals like Bear and Leopard cats | 1. The forest area between Langjophaka and Taba 2. The dense forest on the eastern bank of the Wang Chhu River near Dechencholing |
Protected areas | ||
| 3 | AVIFAUNA | |||
| 1. The valley supports a variety of birds; these
birds habitats are located along the river and streams. 2. Some of the marshlands in Thimphu are the home of endangered Wood Snipe, and other snipes, Wood Cock and Crakes 3. One of the sites behind the swimming pool area supports the habitat of Globally Threatened Wood Snipe bird 4. River also serves as highway for passage of migrant birds. Ducks, Pochards, Kingfishers, Lapwings and Sand Pipers are some of the species found in this valley. |
1. The marshland south of the sewage treatment tank
2. The marshland behind the swimming pool area 3. The water bodies within the golf course near the Dzong 4. Areas near the Taba stretch of the river 5. The forest area on the way to Dechenphu Lhakhang |
Environmental conservation areas | ||
Issues:
1.Uncontroled biotic interference over the forest lands within the city limits,
like clearing of forest lands for road construction and other developments,
cutting of trees for timber, disposing solid wastes, grazing, etc. 2. Pressure
on marshlands, bird habitats, and paddy fields due to urbanization.
Major Data Sources: National Environmental Commission, Nature Conservation Division, MOA., Royal Society for Protection of Nature.