PART I SOME ECOLOGICAL OBSERVATIONS ON MIRIK AND ITS ENVIRONS IN DARJEELING DISTRICT, WEST BENGAL ·. - 13 - INTRODUCTION Since 1866 when the term Ecology was employed first by Ernst Hae­ ckel, who ,invented the word oekologie for "the relation of the animal to its organic as well as its inorganic environment, particularly its friendly or hostile relations to those animals or plants with which it comes in con­ tact," ecology has been variously defiQed by other investigators (Warming, 1909; Daubenmire, 1947; Tansley, 1949; Odum, 1971; Kendeigh, 1980; etc.). At present, the scope of ecology in botany is vast and useful in the realm of applied sciences. Ecology needs field study which consists of re­ cording and examining plant species growing in a vegetation of covered area. The estimates and accounts are . made of the environmental. conditions under which plants are growing. Thus, the plant taxonomic study, described in th~ subsequent chapter becomes very much complementary to the study on ecology of the region. • During the last few decades, Mirik and its a?joining areas specially in 'the catchment part have been subjected to drastic deforestation with in­ adequate_ a forestation, the soil surface has become devoid of any plant cover and due to over insolation of the soil. Leaching of minerals has been in­ creased tremendously (De, 1977). As a result, the f~rtility status of the soil has been decreased.. Thus, the obser:--ation on some· ·of the ecological factors, such as, soil, tl;lmperature, rainfall in the region is very essential. Moreover, due to rapid urbanization the human population has been in­ creasing day by day. It is also very necessary to study the present day sic tuation of human population in the region. The development of the plant depends on the topographical relief of a particular area. This part of con­ sideration has also been taken into account during investigation. Recently, the study on landuse becomes the part of the programme during ecological study in' a region (Odum, 1971 ). It is essential for purpose­ ful utili'7.alion of land in an area. Thus, attempt h~s been made to survey - 14 - the nature. or landuse in the region under study with special· reference to the observation on vegetation types. REVIEW OF LITERATURE Information in connection with the earlier records on history, human population, agriculture and forestry of Darjeeling district are· available in some of the literature (Hooker, 1854; Hunter, 1876; O'Malley, 1907; Dash, 1947). In later period all these information about the same region have been dealt with in several rep~rts (Mitra, 1954; Ray, 1967; Census, 1971; Banerji rt a!., 1980). Physiography, geological aspect and soil have been critically represented by Wadia (1966) specially with reference to India as a whole. The geology of Himalayas has been thoroughly discussed .by some of' the authors (Garwood, 1903; Gansser, 1964). De (1977) discussed the . economy of North Bengal with special reference to agriculture, forestry and plantation. Puri (1960) represented in details about the forest types and vegetation in India a~ a whole. Whitmore (1982) discussed·critically about the management of the forest. Chaudhuri (1969) dealt with the critical quantitative analysis and special ecological features of the ·vegetation of. North Bengal. The. ecology of Himalaya .has recent)/ been discussed critically by Kalapasi (i980) with a view to understanding the present day situation of tfie environment. Impact of climatic; factors on plant community has been well elabo­ rated by Daubenmire (1947, 1974), Etherington (1975), Whitmore (1982), though earlier records on the sketch of climate and vegetation of Hima- . layas were described by Thomson (1852), Hooker (1854) and O'Malley (1907). Later on, a number of authors (Biswas, 1966; Hara, .1966 & 1971) reflected the environmental conditions of some of the' places in the Eastern Himalaya other than Mirik P.S. with special reference to. rainfall, temperature, humi~ dity and soil factors. - 15 - METHODOLOGY The work was carried out on the following lines of investigation 1. Survey in connection with the accumulation of various information: Information in connection with .physiography, drainage, soil, climate, human population and landuse have been carried out after being contacted with local people, office of Gram Panchayat, local Police Station, Govern­ ment Offices, specially the Directorate of Agriculture and Forestry and local tea gardens. Meteorological data was collected specially from the record of tea gardens and Meteorological stations at Siliguri and Calcutta (Alipur). In­ formation collected after survey were compiled and worked in collabora­ tion with the National Atlas and Thematic Mapping Organisation, Govern­ ment of India. 2. Collection and identification of different plant materials : Collection of various plant materials was performed specially during the study on vegetation. !"roper identification of collected materials was done after comparing the prepared herbarium sheets. with those available in various herbarium sections of North Bengal University, Lloyd Botanic Gardens in Darjeeling, Central National Herbarium (Botanical Survey of India, Howrah, Calcutta) and Indian Museum (Calcutta). Vegetation types were classified according to physiognomy and stru­ ctural features of the plant specially in relation to the altitude of the hill and climatic condition. 10656'7 ?. 2 DEC 10.90 LOCATION MIRIK POLICE STATION, DARJEELING DISTRICf, W.B. 88' 89' NEPAL • Phopar Kheti 27' 27' WEST BENGAL ,··· ~· ' Z6"Ll~~---L~--------~------------L---------~---------------·~'J_ ________-Ja•• 88C Knh. 1U II Ill 20 Km"- 89° L_ Fig. 1. ~·~~--~~~~~--~~ MIRIK & ITS ENVIRONS r--~;;.---.....:;.::~~~~~~~89-=-.-.. -----....... <I 26" ' L --------~--~---.:"'~'~"='="""="===;;;'"==~1U=d,l ====~=---~----~--~~~~--------------_j:d.'lll Knh. i~ Fig. 2. MAP OF MIRIK LAKE ~U~~~i[\~~·lA\ DARJEELING DISTRICf, W.B. REFERENCES Agricullural Land ~ Forest area ~ Jhoras & Conservation Area V~.::-:::,::;:.1 Fellow & Grassland [II] Unmetalled Road Dam Spring Area of the Lake 143000 Sq. mts. Mean height of the Lake 1580 mts. above M.S.L. Fig. 3. RELIEF MIRIK POLICE STATION DARJEELING DISTRICT, W.B. 26° 50' REFERENCES Heights in metres Less than 300 bd 300-600 m 600-900 ~ 900-1200 am . 1200-1500 ~·lore than 1500 •m 1 1 I 88° 10' 15' ,----, Fig. 4. TOPOGRAPHIC SECTION FROM THE HIGHEST ELEVATION OF MIRIK P. S. TO THE BASE LEVEL AT BALASON VALLEY ~ 0 "~ ~ 00"' 0 mts. L------------------__Jl < 700 mts.---Lower Erosional Surface 700-1000 mts. ---Middle Erosional Surface > 1000 mts. - -- Upper Erosional Surface of the Mountains Scale : Horizontal II 1 Cm. ~ 500 mts Vertical ·• ' Fig. 5• . rL DRAINAGE ' i ,.-·--' MffiiK POLICE STATION, 55' J \ /-· DARJEELING DISTRICf, W.B. I...__ _ _,. / 26' 50' 88° 10' 15' J Fig. 6. cg ---- . • • r SLOPE 55' r- if/3 I--~\ MIRIK POLICE STATION - .!_:,J -~ / DARJEELING DISTRICf, W.B. "' ~ f_y.; ..__ ® Mirik "' ~ --~ I~~: -..----"-"'-"'-"CE_s ------, Slope zones in % Pc. Less than 20 20-30 30-40 40-50 More than 50 \l,·n.- ((Uf ;m II IS' ( ' 1 Fig. 8. SOIL MffiiK POLICE STATION DARJEELING DISTRICT, W.B. REFERENCES Red Podsol Brown Earth Ash-Grey Soils with association o:' Red Soils. =~ Whitish-Grey Soils []IDI Grey Soils with association rmm1mm ·'' ofYellowish Brown Soils lWlli!llil 88' l L __ J Fig. 9. POPULATION DENSITY 1981 . MIRIK POLICE STATION, DARJEELING DISTRICT, W .B . .,,. 50' REFERENCES Persons ha Less than I 1~3 / 4-6 J-9 More than 9 \_ I I i 1 1S' Fig. 10. ·. P. S. MIRIK GROWI'H OF POPULATION 1901-1981 25 ! :o' 20 c "';:l .o .s;;: !-< .5 IS ~ 5 ! '. 0+---~r----r----~--~r----r----~--~----~; 1901 '11 '21 '31 '41 '51 '61 . '71 '811 Census Years ' Ffig. 11. 88° 10' 15' .---~--~~~----------------------· SUKHIAPOKRI P. s. ADMINISTRATIVE ( ,...... MIRIK POLICE STATION, 55' ~' ) __.....--·,.. \_,PARJEELING DISTRICT, W.B. 55' ,~~ ~--·""'' 1 .-...;,~ _,. 1 I /ill/1K~q~~- ~ · I I •«~-· i OKAYTI T.G.I I .....,;;;, ~- t'(RONGDONG) ~ rJ MIRIK KIIASMAHAL --~ ·. I MIRIK @)';- \\ I I '''Q. 1 II ·,_ I ·. ..._..._..... .. ~ BUKIM T.G. tTharbol "<;/ .,....---··\-- ..... , __ I I PHUGURI\ 1 -..:;: •• I ( FQREST J l )'~ 1\l'- I \ ~-. I \ ',_~ ~) ~---------j \ SAORENI / ........ --,.._ __ \~ ··- \ I II ..... ..._ I I I \ I < ' -< I. PASCH 1M I I I i PHUGURI T.G. \ 1 \ MANJWA .. , I ·., ') I I ' : /\ ,,--\ ~ .. ,, ,' \ , __ J \ tr '-....._ //\ SINGBALI T.G. / ......... .....--t__ / \ / - ' __ ,.. \ / PURBA,PHUGURJ_ __..... -,_..,.--.( '- T.G.t .... ....... _ ~ ......... \ \ ......... TINGLING T.G. \I ..... 'i NEW FALLODI T.G. 26' ..... -J.. IGAYABARII 50' (----<:,. ........ \ ', ' ) \ ........... _...... - ..... ,_... I ', \ \ ' '- REFERENCES ., MANJHA FOREST \ -....._ .,.-z (PANIGIIATA F. R.) \I ----- Boundanes: \ / PATONG T.G. International I Police Station ~! '\ : Village r ., I --- ........ ·- \ -----;;;-- Police Station HQrts. ® i ·,., \_----- ( ~ Important Roads _, "" PANIGHATA M B ,.,.; \ / \ r·---·/ . I \ f",/' ~- \ NAXALBARI P. S. \ 88' 10' 15' m~tnos HU) .'al 1 Km•. /"'---~ '· Fig. 12. LAND USE MIRIK POLICE STAUON DARJEELING DISTRICf, W.B • . I ·'. AEFEAEI<CeS Rural Settlements Croplands Plantations (Tea Gardens) Forests Scrubs Wastelands Important Roads Mme. 1000. 500 1 Km•. l .( Fig. 13.' - 16 - OBSERVATION AND DISCUSSION. Physiography with special reference to slope, river system, drainage, water­ shed and soil : The district of Darjeeling lies between 26°31' and 27°13' N. lat. and qetween 87°59' and 88°53'' E. long. and its total area is about 3108 sq.kms