Biodiversity of Arunachal Pradesh: Flora, Fauna, Forests, Wildlife and Conservation
Arunachal Pradesh is one of India's most biologically diverse states and an important part of the Eastern Himalaya biodiversity region. Its enormous variation in altitude, climate, rainfall, forests, rivers and terrain creates a wide range of habitats, supporting thousands of species of plants, animals, birds, orchids and other organisms.
From tropical forests in the foothills to temperate forests, coniferous vegetation, sub-alpine landscapes and alpine environments, the biodiversity of Arunachal Pradesh reflects one of the most remarkable ecological gradients in India.
The state is particularly important for its rich flora, diverse wildlife, orchids, birds, medicinal plants and high-altitude ecosystems. Its protected landscapes, including Namdapha, Pakke, Mouling and the Dihang-Dibang region, play an important role in conserving this biological wealth.
Quick Fact: Arunachal Pradesh lies within the Eastern Himalaya, one of the world's important biodiversity regions, and contains a remarkable range of ecosystems within a relatively small geographical area.
Table of Contents
What Makes Arunachal Pradesh Biodiverse?
Geographical Basis of Biodiversity
Forest Biodiversity
Flora of Arunachal Pradesh
Orchid Diversity
Medicinal Plants
Fauna of Arunachal Pradesh
Mammals
Bird Diversity
Butterflies and Insects
Aquatic Biodiversity
Namdapha National Park
Dihang-Dibang Biosphere Reserve
Mouling National Park
Mehao Wildlife Sanctuary
Indigenous Knowledge and Biodiversity
Threats to Biodiversity
Biodiversity Conservation
Important Biodiversity Facts
Frequently Asked Questions
Conclusion
What Makes Arunachal Pradesh So Biodiverse?
The exceptional biodiversity of Arunachal Pradesh is primarily associated with its geographical position and environmental variation.
The state extends from the Himalayan foothills to high mountain environments. Consequently, temperature, rainfall, soil, vegetation and habitat conditions change considerably with altitude.
These variations produce a sequence of ecosystems that may include:
Tropical forests
Subtropical forests
Moist deciduous forests
Temperate broad-leaved forests
Coniferous forests
Sub-alpine vegetation
Alpine meadows
High-altitude ecosystems
Riverine and freshwater habitats
The state's location in the Eastern Himalaya further increases its biological importance because several major biogeographical influences meet in this region.
Geographical Basis of Arunachal Pradesh Biodiversity
1. Altitudinal Variation
Altitude is one of the most important factors controlling vegetation and wildlife distribution in Arunachal Pradesh.
Species found in the warm and humid foothills are different from those adapted to colder mountain environments. In some protected landscapes, the change from lowland tropical forest to high-altitude vegetation occurs across a comparatively short horizontal distance.
Namdapha National Park is an outstanding example. Its elevation ranges from approximately 200 metres to 4,571 metres, creating several distinct ecological environments within one protected landscape.
2. Climate
Arunachal Pradesh receives substantial rainfall, particularly in its lower and eastern areas. Temperature and precipitation vary considerably with elevation and geographical location.
This climatic diversity contributes to the development of different forest communities and supports a large number of ecological niches.
3. Eastern Himalayan Location
Arunachal Pradesh forms part of the Eastern Himalaya, a globally significant region for biological diversity.
The interaction between Himalayan, Indo-Malayan and other biogeographical influences has contributed to the state's rich mixture of tropical, subtropical, temperate and alpine organisms.
Forest Biodiversity of Arunachal Pradesh
Forests are the principal foundation of biodiversity in Arunachal Pradesh.
According to the Forest Survey of India's India State of Forest Report 2021, Arunachal Pradesh had approximately 66,430.67 sq km of forest cover, representing about 79.33% of its geographical area.
The 2021 assessment classified the state's forest cover into different density categories, including very dense, moderately dense and open forests.
Because forest-cover assessments are periodically updated, the assessment year should always be specified when using these figures.
Major Forest Types
The broad forest environments of Arunachal Pradesh include:
Tropical evergreen forests
Tropical semi-evergreen forests
Moist deciduous forests
Subtropical broad-leaved forests
Subtropical pine forests
Temperate broad-leaved forests
Temperate coniferous forests
Sub-alpine forests and vegetation
Alpine vegetation
This altitudinal sequence provides habitat for species with very different ecological requirements.
Flora of Arunachal Pradesh
The flora of Arunachal Pradesh is among the richest in India.
The state's recent State Biodiversity Strategy and Action Plan 2025–2035 records approximately 5,192 angiosperm species.
These flowering plants occur across a wide range of ecosystems, from lowland tropical forests to high-altitude environments.
The state's plant diversity includes:
Trees
Shrubs
Herbs
Climbers
Grasses
Bamboos
Ferns
Orchids
Rhododendrons
Medicinal plants
Alpine plants
The large variation in vegetation is one of the strongest indicators of Arunachal Pradesh's ecological complexity.
Orchid Diversity of Arunachal Pradesh
Orchids are one of the most notable components of the state's flora.
The recent state biodiversity strategy records approximately 678 orchid species.
High humidity, forest structure, elevation and the availability of suitable host trees create favourable conditions for epiphytic and terrestrial orchids.
Important areas for orchid diversity include:
Sessa Orchid Sanctuary
Namdapha
Dihang-Dibang region
Eastern Himalayan forest landscapes
Other humid mountain forests
The Botanical Survey of India has undertaken extensive botanical exploration in Arunachal Pradesh and has produced important floristic and orchid-related research.
Medicinal Plants of Arunachal Pradesh
Arunachal Pradesh is also rich in medicinal plants.
The Forest Department reports more than 500 medicinal plant species from the state.
Medicinal plants occur across several ecological zones, and traditional communities have accumulated extensive knowledge regarding their identification and use.
Examples of important medicinal plant groups reported from the state include plants belonging to genera such as:
Coptis
Taxus
Panax
Illicium
Aconitum
Tinospora
The conservation of medicinal plants is therefore important for both biodiversity protection and the preservation of traditional ecological knowledge.
Fauna of Arunachal Pradesh
The fauna of Arunachal Pradesh includes an exceptional variety of mammals, birds, reptiles, amphibians, fishes, butterflies and other organisms.
The state's recent biodiversity strategy records approximately:
85 terrestrial mammal species
650 bird species
However, older inventories and broader Forest Department datasets may report higher numbers because they can use different taxonomic categories, survey periods or geographical scopes.
Therefore, biodiversity statistics should always be interpreted according to their source, methodology and assessment year.
Mammals of Arunachal Pradesh
The forests and mountains of Arunachal Pradesh provide habitat for many important Himalayan and Indo-Malayan mammals.
Notable species include:
Tiger
Clouded leopard
Snow leopard
Leopard cat
Marbled cat
Asiatic golden cat
Red panda
Takin
Himalayan serow
Goral
Musk deer
Himalayan black bear
Dhole
Several primate species
Various small carnivores
Different species occupy different elevations and habitats.
For example, the red panda is associated primarily with suitable high-altitude forest environments, while tropical and subtropical forests support a different assemblage of mammals.
Four Big Cats of Namdapha
Namdapha is particularly significant because of its extraordinary range of habitats.
The protected landscape is associated with four major wild cat species:
Tiger
Leopard
Clouded leopard
Snow leopard
The presence of these species across a large elevation gradient illustrates the ecological importance of Namdapha.
It is important, however, to distinguish between species reported or historically recorded from a landscape and current population estimates. Presence records do not automatically indicate stable populations.
Bird Diversity of Arunachal Pradesh
Arunachal Pradesh is one of India's most important regions for bird diversity.
Its forests and mountain ecosystems provide habitat for numerous Himalayan, Indo-Malayan and Eastern Himalayan bird species.
The recent state biodiversity strategy records approximately 650 bird species.
Important bird habitats occur in areas such as:
Eaglenest Wildlife Sanctuary
Pakke Tiger Reserve
Namdapha National Park
Sessa Orchid Sanctuary
Dihang-Dibang region
Tawang and surrounding high-altitude landscapes
The state's bird diversity is strongly influenced by its varied elevation, forest structure and geographical location.
Butterflies and Insects
The humid forests and diverse elevations of Arunachal Pradesh support a rich insect fauna.
Butterflies are particularly useful for understanding habitat diversity because many species are closely associated with particular ecological conditions.
The Arunachal Pradesh Forest Department estimates approximately 900 butterfly species in the state.
Individual protected areas can also contain substantial butterfly diversity. For example, the Forest Department reports 232 butterfly species from Mehao Wildlife Sanctuary.
Insects are also significant from an ethnobiological perspective because some indigenous communities traditionally use particular insect species as food or for other purposes.
Aquatic Biodiversity
The rivers and streams of Arunachal Pradesh are an important but sometimes overlooked part of its biodiversity.
The state's mountainous terrain generates numerous streams and river systems that eventually form major tributaries of the Brahmaputra and other drainage networks.
Aquatic biodiversity varies according to:
Altitude
Water temperature
Flow velocity
River substrate
Seasonal rainfall
Sediment
Connectivity between habitats
Fish diversity is therefore closely related to the physical characteristics of individual rivers and streams.
The Arunachal Pradesh Biodiversity Board has documented research on the state's ichthyofaunal diversity, highlighting the importance of freshwater ecosystems.
Namdapha National Park and Tiger Reserve
Namdapha National Park and Tiger Reserve is one of the most important biodiversity landscapes of Arunachal Pradesh.
Its elevation ranges from approximately 200 metres to 4,571 metres, creating an exceptional ecological gradient.
Botanical investigations have recorded a wide variety of plant groups in Namdapha, including:
Lichens
Bryophytes
Pteridophytes
Gymnosperms
Angiosperms
The Forest Department has reported 801 angiosperm species from the protected landscape, along with substantial diversity among lower plant groups.
Namdapha is also important for large mammals, carnivores, birds and numerous smaller organisms.
Its location near the India–Myanmar region adds further biogeographical importance.
Dihang-Dibang Biosphere Reserve
The Dihang-Dibang Biosphere Reserve is another major biodiversity landscape.
The Forest Department reports an area of approximately 5,112 sq km.
The reserve contains an extraordinary altitudinal sequence extending from lower tropical environments towards high mountain and alpine conditions.
Its biodiversity includes:
Takin
Red panda
Serow
Musk deer
Himalayan black bear
Wild dog
Various birds
Orchids
Rhododendrons
Primulas
Medicinal plants
The reserve demonstrates how changes in altitude can produce major ecological transitions within one continuous mountain landscape.
Mouling National Park
Mouling National Park is situated in the eastern part of Arunachal Pradesh and covers approximately 483 sq km.
Its elevation ranges from about 750 metres to 3,064 metres.
The park protects a substantial tract of Eastern Himalayan forest and provides habitat for numerous mammals and birds.
Its ecological significance is strengthened by its relationship with the wider Siang and Dihang-Dibang landscape.
Mehao Wildlife Sanctuary
Mehao Wildlife Sanctuary in Lower Dibang Valley is another important biodiversity area.
The Forest Department reports approximately:
60 mammal species
200 bird species
232 butterfly species
13 snake species
6 fish species
The sanctuary is associated with species such as:
Clouded leopard
Marbled cat
Wild dog
Spotted linsang
Himalayan black bear
Red panda
Its combination of forest, elevation and water resources makes it an important habitat for both terrestrial and aquatic organisms.
Indigenous Communities and Biodiversity
The biodiversity of Arunachal Pradesh is closely connected with the traditional knowledge of its indigenous communities.
Local knowledge includes the identification and use of:
Medicinal plants
Wild food plants
Bamboo and cane
Forest products
Edible insects
Fish
Agricultural varieties
Traditional natural resources
The People's Biodiversity Register (PBR) system is particularly important because it documents biological resources and associated traditional knowledge at the local level.
This approach recognizes that biodiversity exists beyond formally protected areas.
Village forests, agricultural landscapes, rivers, wetlands and community-managed areas can also contain important biological resources.
Major Threats to Arunachal Pradesh Biodiversity
Despite its enormous biological wealth, Arunachal Pradesh faces several conservation challenges.
Habitat Fragmentation
Roads, settlements, infrastructure and other land-use changes can divide previously continuous habitats.
Fragmentation can restrict animal movement and reduce ecological connectivity.
Climate Change
Changing temperature and precipitation patterns can affect species distributions.
High-altitude species may be particularly vulnerable because suitable climatic conditions can become increasingly restricted.
Unsustainable Resource Use
Excessive extraction of timber, medicinal plants, wildlife and other biological resources can place pressure on sensitive species.
Human-Wildlife Conflict
Expansion of human settlements and infrastructure into wildlife habitats can increase interactions between people and wild animals.
Infrastructure Development
Infrastructure is important for economic and social development, but projects in ecologically sensitive mountain environments require careful planning to reduce habitat loss and fragmentation.
Invasive Species
Disturbed habitats can become more susceptible to invasive species, which may compete with native organisms and alter ecological processes.
Biodiversity Conservation in Arunachal Pradesh
Arunachal Pradesh has established a significant network of protected and conservation landscapes.
According to the state Forest Department, the conservation network includes:
| Protected-area category | Number |
|---|---|
| National Parks | 2 |
| Wildlife Sanctuaries | 13 |
| Tiger Reserves | 3 |
| Elephant Reserves | 2 |
| Community Reserves | 9 |
| Biosphere Reserves | 1 |
Major biodiversity conservation landscapes include:
Namdapha National Park and Tiger Reserve
Pakke Tiger Reserve
Kamlang Tiger Reserve
Mouling National Park
Dihang-Dibang Biosphere Reserve
Dibang Wildlife Sanctuary
Mehao Wildlife Sanctuary
Eaglenest Wildlife Sanctuary
Sessa Orchid Sanctuary
Daying Ering Memorial Wildlife Sanctuary
Conservation programmes include habitat protection, wildlife management, forest restoration, species-specific conservation, biodiversity documentation and community participation.
Importance of Community-Based Conservation
A successful biodiversity strategy for Arunachal Pradesh cannot depend exclusively on protected areas.
Large parts of the state's biological resources occur outside national parks and wildlife sanctuaries.
Community participation can contribute to conservation through:
People's Biodiversity Registers
Biodiversity Management Committees
Traditional resource management
Community forests
Sustainable harvesting
Protection of culturally important species
Local ecological monitoring
Combining scientific research with traditional ecological knowledge can provide a more complete understanding of Arunachal Pradesh's biodiversity.
Biodiversity of Arunachal Pradesh: Important Facts
| Category | Verified Information | Ecological & Regional Context |
|---|---|---|
| Biogeographical Region | Eastern Himalaya | Core zone of the Indo-Burma and Eastern Himalayan biodiversity hotspots |
| Geographical Area | ~83,743 km² | Largest state by land area in Northeast India |
| Forest Cover | ~66,430.67 km² (ISFR 2021) | Massive contiguous tropical, subtropical, and alpine forest canopy |
| Forest-Cover Percentage | ~79.33% (ISFR 2021) | One of the highest proportions of forest cover among Indian states |
| Angiosperms | ~5,192 species | High floral richness spanning lowland rainforests to high alpine meadows |
| Orchids | ~678 species | Commonly designated as the "Orchid State of India" due to immense species density |
| Birds | ~650 species | Major global Important Bird Area (IBA) sheltering rare hornbills and tragopans |
| Terrestrial Mammals | ~85 species | Habitat for flagship species like the Clouded Leopard, Snow Leopard, and Mishmi Takin |
| National Parks | 2 | Namdapha National Park and Mouling National Park |
| Wildlife Sanctuaries | 13 | Covers key sanctuaries like Dibang, Eagle Nest, Kamlang, and Mehao |
| Tiger Reserves | 3 | Namdapha, Pakke, and Kamlang Tiger Reserves |
| Elephant Reserves | 2 | Kameng Elephant Reserve and Deomali Elephant Reserve |
| Community Reserves | 9 | Indigenous community-managed conservation areas protecting local ecosystems |
| Biosphere Reserves | 1 | Dihang-Dibang Biosphere Reserve |
| Major Biosphere Reserve | Dihang-Dibang | High-altitude mega-reserve spanning eastern Himalayan river valleys |
| Major Biodiversity Landscape | Namdapha | World's northernmost lowland evergreen tropical rainforest with extreme altitudinal range |
Data note: Species totals can vary between inventories because surveys, taxonomic classifications and assessment periods differ. Current figures should therefore be quoted with their source and year.
Why Is Arunachal Pradesh Important for Biodiversity?
Arunachal Pradesh is important because it contains an exceptional combination of:
Tropical and Himalayan ecosystems
Large continuous forest landscapes
High plant diversity
Rich orchid flora
Diverse mammalian fauna
Exceptional bird diversity
High-altitude ecosystems
Freshwater habitats
Medicinal plants
Traditional ecological knowledge
Important protected areas
Eastern Himalayan species and habitats
Its greatest conservation value lies not in any single species but in the large-scale ecological connectivity between different habitats and elevations.
Frequently Asked Questions
What is the biodiversity of Arunachal Pradesh?
The biodiversity of Arunachal Pradesh refers to the state's wide variety of ecosystems, plants, animals, birds, insects, fish and other biological resources. Its location in the Eastern Himalaya and large altitudinal range make it one of India's most biologically diverse regions.
Why is Arunachal Pradesh rich in biodiversity?
Arunachal Pradesh is rich in biodiversity because of its large variation in altitude, climate, rainfall, terrain, forests and river systems. Its position in the Eastern Himalaya also brings together different biogeographical influences.
How many plant species are found in Arunachal Pradesh?
The recent Arunachal Pradesh State Biodiversity Strategy and Action Plan records approximately 5,192 angiosperm species in the state.
How many orchid species are found in Arunachal Pradesh?
The recent state biodiversity strategy records approximately 678 orchid species.
How many bird species are found in Arunachal Pradesh?
The recent state biodiversity strategy records approximately 650 bird species.
Which is the most famous biodiversity area in Arunachal Pradesh?
Namdapha National Park and Tiger Reserve is one of the state's most important biodiversity landscapes because of its exceptionally large altitudinal range and diverse forest and wildlife habitats.
Which national parks are found in Arunachal Pradesh?
Arunachal Pradesh has two national parks: Namdapha National Park and Mouling National Park.
What are the major animals found in Arunachal Pradesh?
Important animals include tiger, clouded leopard, snow leopard, red panda, takin, Himalayan serow, musk deer, Himalayan black bear, leopard cat and several other mammals.
Is Arunachal Pradesh a biodiversity hotspot?
Arunachal Pradesh forms part of the Eastern Himalaya, which is recognized as a globally significant biodiversity region and biodiversity hotspot.
Why are forests important for Arunachal Pradesh biodiversity?
Forests provide habitat, food, shelter and breeding areas for plants and animals. They also maintain watersheds, protect soil, regulate local climate and support ecosystem connectivity across the mountains.
Conclusion
The biodiversity of Arunachal Pradesh is a product of its exceptional geography. From tropical forests in the foothills to alpine environments in the high Himalaya, the state contains a remarkable succession of ecosystems.
Its rich flora includes thousands of flowering plants and hundreds of orchids, while its forests support an extraordinary variety of mammals, birds, butterflies and other organisms. Protected landscapes such as Namdapha, Pakke, Mouling, Mehao and Dihang-Dibang are particularly important for maintaining these biological resources.
However, biodiversity conservation cannot be measured only through species counts. Protecting habitats, ecological corridors, rivers, traditional knowledge and community-managed landscapes is equally important.
The long-term conservation of Arunachal Pradesh's biological wealth will depend on balancing infrastructure and economic development with ecological protection, strengthening scientific research, supporting local communities and maintaining the connectivity of Eastern Himalayan ecosystems.
Arunachal Pradesh is therefore not simply a forest-rich state; it is one of India's most significant centres of Himalayan biological diversity.