The whole of Garo Hills region forms a sort of undulating plateau with plenty of flat lands and valleys with altitudes varying from 100-1400 m above sea level, Nokrek being the highest point, i.e, 1418m. The districts has a rich and unique flora and it is supposed to be the original home of the Citrus.
The vegetation of Garo Hills can be broadly classified into the flora of tropical and sub-tropical zones based on altitude.
The tropical vegetation covers areas upto an elevation of about 1000. The majority of the forests viz. Dilma, Dhima, Chimabangsi, Rajasimla Ildek, Darugre, Rongrenggre, Songsak, Siju, Rewak, Emangre, baghmara, Phulbari, Rongmatchokgre, Rongchugre, Singimari etc. fall in this zone. It embraces evergreen, semi-evergreen and deciduous forests, bamboo thickets and grasslands including riparian forests and swamps. These forests mainly consists of Shorea robusta and in certain area Tectona grandis has also been introduced. The tallest trees are Schima wallichii, Terminalia belirilia belirica, Engelhardtia spicata, Aesculus assamica, Aporusa wallichii, Bridelia retusa, Cryptocarya andersonii, Talauma hodgsonii, Lagerstroemia parviflora, Gmelina arborea etc.
Miliusa velutina, Hibiscus macrocarpus, Zizyphus rugosa, Helicia robusta, Engelhardtia spicata var. Colebrooliana and Ficus prostrata etc. form the lower canopy. The main components of Shrubby species are – Capparis zeylanica, Garcinia lancifolia, Bauhinia acuminata, Mimosa himalayayana, Acacia Concinna, Mussaenda Roxburghii, Eupatorium Modiflorum, Solanum Kurzii and Phlogacanthus tubiflorus etc. In a few areas, numerous lianas intertwining the trees e.g. Dysolobium grande, Mucuna bracteata, Fissistigma wallichii, Paederia scanders, Solena heterophylla and Aristolocjia saccata are prominent. Rarely, Aristolochia cathcartii may be seen in certain forests. Several species of bamboo stretch for long distances forming thickets of secondary vegetation without any competition. A few palms like Areca, Caryota, Pinanga and Didymosperma are also conspicuous. The ground flora in deciduous forests is very poor and seasonal, while in evergreen forests, species of Alpinia, Amomum, Colocasia, Costus, Hedychium etc are not uncommon. The epiphytic climbers viz. Rhaphidophora spp., members of Gesneriaceae, Hoya app. With beautiful bunches of star like flowers and stem parasites of Loranthaceae and total root parasite Cuscuta reflexa are also seen. A few species of epiphytic orchids are seen in the evergreen forests but they show less species diversity. The herbaceous vegetation is less profuse and includes the members of Oxalidaceae, Balsaminanceae, Acanthaceae, Leeaceae, Fabaceae, Asteraceae and Poaceae. Ferns and fern-allies, liverworts and mosses etc. are also seen on old tree trunks and stones etc. near water sources, in shady places. Due to excessive ‘Jhum’ practice most of the forest areas are cleared and secondary monoculture forests of Shorea robusta established. In more or less open moist localities and near water sources, herbs like Dictyospermum, Aneilema Scaberrimum, Burmania Sp., Coiictyospermum, Aneilema Scaberrimum, Burmania Sp., Coix sp. Cyprus spp., Oxalis Corniculate, Anemone spp. and Ericcaulon can be seen.
The sub-tropical vegetation occurs at elevations above 1200 m from sea level and this type of forest is restricted in Tura Peak, Nokrek Peak etc. These are mainly evergreen forests but a few elements of deciduous forests are also seen. The top canopy is contributed by Castanopsis hystrix, Betula culindristachvs, Kavea floribunda, Garonia affinis, Cyathocalvx martabanicus, Talauma rabaniania, Taluma phellocarna, Dryntes lancifolia Pasania xylocarpa, Fiscus spp. and vitax altissima Aldina cordifolia, Sterculia villosa, Garuga pinnata, Machilus gamblei, M. Villosa, Milletia orainii, Carnicia paniculata, Sageraea juarina, Symolocus ferruginea, Eriobotrya benghalensis, Emblica offinialis, Ebretia acuminata, Quercus semiserrata, Betula alnoides with Litsea spp. etc. forming the middle canopy of trees. The lowest canopy comprises Aglata roxburghii, Antidesma bunius, Breynia patens, Pasania spicata, Mitrephora tomentosa, Styrax serrulatim, Premna multiflora.
Entada phaseoloides, Conophalus suaveolens, Dalbergia stipulacea, Spatholobus roxburghii and Vitis latifolia etc. stretch from one tree to another in the forests. The high altitude coupled with low temperature and moisture is congenial for the profile growth of epiphytic flora. The branches of old tree trunks are moss-laden and are fully converted by epiphytic orchids, though species diversity is very low. Ferns, liverworts and mosses etc. are also predominant in this region.
The large number of mammalian fauna includes the followings:
|Hoolock gibbon||Stump-tailed macaque||Rhesus macaque|
|Assamese macaque||Slow loris||Golden langur|
|Capped langur||Common monkey||Tiger|
|Leopard||Clouded leopard||Golden cat|
|Leopard cat||Marbled cat||Jungle cat|
|Large Indian civet||Masked Palm civet||Binturong|
|Indian Grey mongoose||Indian fox||Himalayan Black bear|
|Yellow Throated marten||Yellow-Bellied weasel||Madras Tree shrew|
|Indian flyingsquirrel||Malayan Giant squirrel||Bandicoot rat|
|Lesser Bamboo rat||Black Napped hare||Rufous-tailed hare|
|Sambar||Gaur||Indian Crested porcupine|
|Cheetal||Muntjac or Barking deer||Indian elephant|
|Wild dog||Indian Wild boar||Different Species of Bats etc.|
Different varieties of beautiful birds are in abundance in the forest areas of the region. They are
|Indian black baza||Barred jungle owlet||Red jungle-fowl|
|Thick-billed green pigeon||Blue throated barbet||Long-tailed broadbill|
|Grey-headed myna||Jungle myna||Green magpie|
|Indian house crow||Red winged crested cuckoo||Large green-billed malkoha|
|Crow pheasant||Red headed trogon||Redwattled lapwing|
|Burmese roller||Broad-billed roller||Spur-winged plover|
|Indian three-toed forest kingfisher|
Some other varieties of birds like the White-crested Laughing Thrush, Scarlet Minivet, Black-headed Oriole, Cockoo-shrike, Green Barbet, Chloropsis, Green Himalayan Barbet, White–capped Redstart, Magpie Robin, Yellow Bulbul, Brown Fish Owl, Bee-Eaters, Serpent Eagle, Hill Myna, Pied Myna, Grey-headed Sibia, Slaty-headed Scimitar Babbler as well as various species of Hornbills, Nightjars, Egrets, Parrots, Swallow-Shrikes have also been reported.
Reptile fauna include different varieties of lizards, snakes, turtle/tortoises. Different species of lizards, geckos and skinks include Calotes Emma, C. Maria, C. Versicolor, Cnemaspis Jerdoni, Cytodac Tylus Khasiensis, Cosymbotus Platyrus, Hemidactylus Brooki, H. Frenatus, Gekko Gecko, Japalura Planidorsata etc.
Different species of snakes include Blind snakes, Indian Gamma, Checkered Keelback, Red necked Keelback and others Important poisonous species include Indian Cobra and Vipers
Most of the economic mineral resources of Garo Hills are associated with the Eocene Tertiary, Sedimentary formation. These minerals are Coal, Limestone, Lithomargic clay, Fireclay, Phosphorite, Gypsum and Glass sand.
Coal: The total estimated reserves of coal in Garo Hills Districts is of the order of 359.00 million tones spread over three coalfields viz., West Daranggre, Siju and Pendengru-Balpakram coalfields. Of these, only the West Daranggre coalfield has been opened and worked to a small extent. A block of this coalfield of about 244 hectares was operated by the MIDC Ltd. Annual production from the Nongalbibra colliery of MIDC Ltd. was of the order of 10,000 tonnes. Plans are afoot for exploiting this coalfield for thermal power generation and for use in the proposed cement plant.
Limestone: The total estimated reserves of limestone in Garo Hills is of the order of 510 million tones. Of this, more than 460 million tones is in a single deposit at Siju Arteka in South Garo Hills. So far, the limestone deposits of Garo Hills have not been worked for commercial purpose except a small quantity in the Siju area along the Nongalbibra-Baghmara road, which has been quarried for road metals.
Lithomargic Clay and Fireclay: These clays are associated with the coal deposits of the West Daranggre coalfields. The estimated reserve of the lithomargic clay and fireclay is of the order of 80 million tones, out of which fireclay reserve is 70 million tones. Tests conducted on these clays show that they can be utilized for production of high-class refractory bricks and insulators
Phosphorite, Gypsum and Glass-sand deposits found so far are not of economic importance.
There are also other minerals, which are associated with the Aechaean-gneissic complex of the Shillong group of rocks. These are Kaolin or China clay, Quartzite, Feldspar, Banded haematite-quartzite, Sillimanite, Granites and Dolerites. A deposit of good quantity Kaolin or Chaina Clay of economic importance has been located in the Darugre area in the district. A block of this deposit, which has been investigated, has an estimated reserve of 1.20 million tones of good clay. The adjoining areas which are yet to be explored also contain sizeable quantity of this clay. A clay washery is proposed to be set up at Darugre in the area to utilize this deposit for use in various industries.