State of Environment in Bhutan

Abstract

The state of environment of this book is a prelude to the ensuing chapters that provide a comprehensive assessment of the conservation priorities for Bhutan. It provides a review of the country’s geopolitical setting, agro-ecological zones, and land use patterns that influences the biological diversity and conservation efforts. Bhutan’s GNH policy that closely embraces environmental conservation as one of the main building blocks of achieving happiness and sustainable future – through extensive forest cover, protective area network and biological corridor, and empowerment of communities with forest management systems – is the key to Bhutan’s national development policy and strategies. The fundamental principles of other national policies including environmental policies and conservation success emanate from the GNH philosophy and deep-rooted Buddhist perspectives.

Annexures

Annexure 1.1: Classification and characteristics of vegetation zones in Bhutan (Grierson & Long, 1983, see 19)

S.N.	Zone, altitude, and precipitation	Characteristic tree species	Type of forest
1	Subtropical forest 200–1000 m; 250–500 cm	Acrocarpus fraxinifolius, Ailanthus grandis, Bombax ceiba, Crateva religiosa, Dillenia pentagyna, Duabanga grandiflora, Gmelina arborea, Leea asiatica, Musa, Pandanus, Pterospermum acerifolium, Shorea robusta, Tetrameles nudiflora, Thunbergia	Subtropical and largely deciduous forest with much conversion to agriculture in most accessible areas
2	Warm broadleaved forest, 1000–2000 m; 230–400 cm	Alangium chinense, Altingia excelsa, Bischofia javanica, Callicarpa arborea, Castanopsis indica, Cordia obliqua, Dendrocalamus hookeri, Dichroa febrifuga, Engelhardia spicata, Entada pursaetha, Euodia fraxinfolia, Firmiana colorata, Helicia nilagirica, Macaranga pustulata, Maclura cochinchinensis, Maesa spp., Mussaenda roxburghii, Ostodes paniculata, Pouzolzia sanguinea, Rhaphidophora eximia, Schima wallichii, Stereospermum personatum, Trevesia palmata, Wendlandia puberula	Mixture of evergreen and deciduous species. Often cleared for grazing and farming
3	Chir pine forest, 900–1800 m; 100–130 cm	Buddleja asiatica, B. bhutanica, Cycas pectinata, Cymbopogon flexuosus, Euphorbia royleana, Ficus oligodon, Grewia sapida, Indigofera dosua, Osyris lanceolata, Pinus roxburghii, Rhus paniculata, Securinega suffruticosa, Solanum erianthum, Woodfordia fruticosa, Ziziphus incurva	Dry forest on shallow soils and southern aspects. Much degradation due to grazing, felling, and burning. Associated with lemon grass in eastern Bhutan, susceptible to fire
4	Cool broadleaved forest, 2000–2900 m; 250–500 cm	Acer campbellii, A. sterculiaceum, Betula alnoides, Brassaiopsis alpina, Chirita lachensis, Corylopsis himalayana, Elatostema monandrum, E. obtusum, Exbucklandia populnea, Helwingia himalaica, Ilex fragilis, Lecanthus peduncularis, Lindera nessiana, L. pulcherrima, Persea clarkeana, Pilea bracteosa, Rosa moschata, Rubus lineatus, R. pentagonus, R. treutleri, Schisandra grandiflora, Symplocos dryophila	Evergreen and deciduous forest, on moist slopes with a north aspect especially in eastern Bhutan, at the expense of blue pine forest due to moist climate
5	Evergreen oak forest, 1800–2000 m, 200–300 cm	Acer campbellii, Castanopsis hystrix, C. tribuloides, Elatostema hookerianum, E. sessile, Galeola lindleyana, Juglans regia, Pilea symmeria, Quercus lamellosa, Skimmia arborescens, Symplocos lucida	Drier than cool broadleaved forest. Felling for grazing, fodder, and fuelwood
6	Blue pine forest, 2100–3000; 70–120 cm	Arisaema consanguineum, Berberis asiatica, Berchemia edgeworthii, Ceratostigma griffithii, Cotoneaster griffithii, Elaeagnus parvifolia, Euonymus grandiflorus, Indigofera heterantha, Jasminum humile, Leptodermis scabrida, Lonicera quinquelocularis, Lyonia ovalifolia, Ophiopogon intermedius, Philadelphus tomentosus, Pinus wallichiana, Polygala sibirica, Prinsepia utilis, Quercus griffithii, Q. semecarpifolia, Rhododendron arboreum, Rosa sericea, Spiraea canescens, Zanthoxylum armatum	Inner dry valleys, on disturbed or burnt ground, transition into spruce, hemlock, and fir, susceptible to fire
7	Spruce forest, 2500–3100 m; 70–100 cm	Acer cappadocicum, A. pectinatum, Berberis praecipua, Enkianthus deflexus, Larix griffithiana, Lindera heterophylla, Salix daltoniana, Salvia campanulata, Taxus baccata	Drier than hemlock forest
8	Hemlock forest, 2800–3100 m, 130–200 mm	Arundinaria griffithiana, Betula utilis, Buddleja colvilei, Daphne bholua, Gaultheria fragrantissima, Larix griffithiana, Litsea sericea, Maddenia himalaica, Magnolia globosa, Panax pseudoginseng, Rhododendron falconeri, R. hodgsonii, R. keysii, Rubus calophyllus, R. pentagonus, Sorbus thibetica, Tsuga dumosa, Viburnum mullaha	On wetter sites than spruce forest. Mixes with Pinus wallichiana and Quercus sp. at lower elevations. Disturbed areas colonized by small bamboo (Arundinaria species)
9	Fir forest, 3000–3800 m, 130 cm or more	Abies densa, Arundinaria maling, Betula utilis, Bryocarpum himalaicum, Primula denticulata, Prunus rufa, Rheum acuminatum, Rhododendron cinnabarinum, R. hodgsonii, Ribes takare, Rubus fragarioides, Skimmia laureola, Sorbus foliolosa, Viburnum nervosum	Highest forest ridges, cleared for grazing, colonized with small bamboo (Arundinaria species)
10	Juniper/rhododendron scrub, 3700–4200 m	Gaultheria trichophylla, Juniperus recurva, J. squamata, Morina nepalensis, Pedicularis megalantha, Phlomis tibetica, Potentilla arbuscula, Primula sikkimensis, Rhododendron lepidotum, Thalictrum chelidonii, Trollius pumilus	Excessive grazing areas, tendency for conversion to grassland
11	Dry alpine scrub, 4000–4600 m	Aconitum orochryseum, Astragalus acaulis, Chesneya nubigena, Cremanthodium thomsonii, Ephedra gerardiana, Meconopsis simplicifolia, Picrorhiza scrophulariifolia, Primula calderiana, Rheum nobile, Rhododendron anthopogon, Salix lindleyana, Saussurea gossypiphora, S. obvallata, Saxifraga moorcroftiana, Tanacetum gossypinum, Thermopsis barbata	Above the tree line

Annexure 1.2: Description of Classification of Land Cover Class and Sub-Class in Bhutan (See 20)

Land cover class & sub-class	Description
1. Forest	Forests means land with trees spanning more than 0.5 ha with trees higher than 5 m and a canopy cover of more than 10%. It does not include land that is predominantly under agricultural or urban land use (National Forest Policy of Bhutan 2011)
1.1. Blue pine forest	Consists of pure or dominant stands of blue pine, usually at an altitude between 1500 m and 3200 m asl. Smaller areas of mixed conifers and broadleaved forest may occur interspersed in the blue pine mapping unit, but because of their small areas they are often left unrecorded
1.2. Chir pine forest	Consists normally of pure stands of chir pine, usually at altitudes between 700 m and 2000  m asl. at relatively dry areas. However, in depressions and water courses, broadleaved might occur, but these areas are usually small and included within the chir pine mapping unit
1.3. Mixed conifer forest	Includes mixed stands of spruce, hemlock, juniper, fir, larch, taxus, and blue pine. Some broadleaved inclusions are also common particularly oaks, rhododendron, maple, and birch. It usually occurs between 2500 m and 3500 m asl.
1.4. Fir forest	Consists either of largely pure stands of fir or few stands of other species such as junipers, taxus, and larch. This category occurs mostly above 3000 m asl.
2. Alpine scrub.	Woody plant characterized by stunted growth (height less than 5 m) due to harsh condition. They are found at higher elevation above 3500 m asl. Close to tree line. Predominant species includes dwarf rhododendrons and junipers
3. Shrubs	Perennial plants with persistent and woody stem without any defined main stem with height less than 5 m. It also includes abandoned agricultural fields with overgrown bushes and other regeneration in disturbed areas
4. Meadows	Include any areas dominated by grasses or any herbaceous plant without or with few scattered trees or shrubs on it. It occurs at all elevations but is relatively more common at higher elevations
5. Cultivated agricultural land	Includes only those agricultural land that are cultivated at the time of land cover assessment. It is further divided into sub-classes
5.1. Chuzhing	Irrigated and/or bench-terraced agricultural land for paddy-based cropping systems
5.2 Kamzhing	Cultivated rain-fed areas (dry land). Some Kamzhing lands have certain level of land shaping
5.3 Orchards	Refers to planted fruit-bearing trees like apple, orange, areca nut, etc.
6. Built-up areas	Includes artificial constructions covering the land with an impervious (e.g., concrete, CGI sheet, thatch) surface. It includes airport, rural settlements, urban areas, schools & institutes, industrial areas, hospital premises, sewage treatment plant, sports and leisure facilities, and roads
7. Non-built-up areas	Absence of the original (semi-) natural cover mainly due to anthropogenic factors. It includes waste dump sites, mines, stone quarries, and other extraction sites
8. Water bodies	Natural and artificially created water bodies. It is further dived into two sub-classes
8.1. Lakes	Area of perennial and natural water surrounded by land. It includes both natural and manmade
8.2. Rivers	Perennial flow of water and the river beds. It also includes artificially constructed reservoir (dam) along the course of perennial rivers
9. Snow and glaciers	Includes both perpetual and seasonal snow cover and glaciers
10. Moraines	Mass of rocks and sediments carried down and deposited by a glacier typically as ridges at its edges or extremity
11. Scree	Mass of small loose stones that form or cover a slope on a mountain
12. Landslide	Includes mass movement of soils debris due to gravitational force triggered by other factors such as rainfall and earthquakes
13. Rocky outcrops	Rocky outcrops refer to natural cliffs and rocky areas