Forest Types of North East India

Over the century, Northeastern India has gained worldwide attention for its diverse and extensive forest cover. Forests of this region are unique, both in terms of their structure and species composition.

Climate, physiography and soils of the region have provided favorable conditions for luxuriant growth of natural vegetation. As the physiography varies from low lying swamps and marshes, to high mountain ridges lying above 6000 m, the soils vary from sand, silt and loam to laterite. The climate of the region seems to have the most telling effect on the vegetation type. The region has one of the heaviest rain falls in the world. Although the average annual rainfall of the region is about 250 cm it varies from place to place. The heavy rainfall which comes from May to September, keeps the relative humidity of the area very high throughout the year. Temperature variation is low, remaining normally between 12 ⁰ C and 35 ⁰ C except in the high hills. These favorable climatic conditions, augmented by fertility of the soils provide for the astounding diversity of flora and fauna characteristic of the region.

Champion and Seth (1968) distinguished 51 types of forests in North East India under 13 broad categories as shown below

I. Tropical Wet Evergreen Forests

1.  Assam valley tropical wet evergreen forest

2.  Upper Assam valley tropical evergreen forest

3.  Cachar tropical evergreen forest

4.  Cane brakes

5.  Wet bamboo brakes

6.  Pioneer Euphorbiaceous scrub

II. Tropical Semi-Evergreen Forests

7.  Assam valley semi-evergreen forest

8.  Sub-Himalayan high alluvial semi-evergreen forest

9.  Syzgium parkland

10. Eastern alluvial secondary semi-evergreen forest

11. Sub-Himalayan secondary wet mixed forest

12. Cachar semi-evergreen forest

13. Moist bamboo brakes

14. Secondary moist bamboo brakes

III. Tropical Moist Deciduous Forests

15. Very moist sal forest

16. Moist plains sal forest

17. Moist sal savannah

18. East Himalayan moist mixed deciduous forest

19. Northern secondary moist mixed deciduous forest

20. Secondary Euphorbiaceous scrub

21. Low alluvial savannah woodland

22. Eastern hollock forest

IV. Littoral and swamp Forests

23. Sub-montane hill valley swamp forest

24. Creeper swamp forest

25. Tropical seasonal swamp forest

26. Eastern wet alluvial grassland

27. Riparian fringing forest

V. Tropical Dry Deciduous Forests

28. Khair-sissu forest

VI. Subtropical Broad-leaved Hill Forests

29. Khasi sub-tropical hill forest

30. Assam sub-tropical hill savannah woodland

VII. Subtropical Pine Forests

31. Assam sub-tropical pine forest

32. Assam sub-tropical pine savannah

VIII. Montane Wet Temperate Forests

33. East Himalayan wet temperate forest

34. Naga hills wet temperate forest

IX. Himalayan Moist Temperate Forests

35. East Himalayan moist temperate forest

36. Cypress forest

37. Montane bamboo brakes

38. Alder forest

39. Low level blue pine forest

X. Himalayan Dry Temperate Forests

40. East Himalayan dry temperate coniferous forest

41. Larch forest

42. East Himalayan dry juniper/birch forest

43. East Himalayan dry juniper/birch forest

XI. Sub-Alpine Forests

44. East Himalayan sub-alpine birch/fir forest

45. Sub-alpine blue pine forest

46. Sub-alpine pasture

XII. Moist Alpine Scrub

47. Birch/Rhododendron scrub

48. Deciduous alpine scrub

49. Dwarf Rhododendron scrub

XIII. Dry Alpine Scrub

50. Dry alpine scrub

51. Dwarf juniper scrub