TYPES OF FOREST. 129 



going east, exceeding 100 incites in the eastern Himalayas. The 

 relative humidity is generally high except in the north-west 

 frontier districts. As a general rule, the rainfall decreases in the 

 inner hills. In the North-west Frontier the chief trees are 

 species of juniper. In the Punjab and United Provinces hiUs 

 the following trees are the most important : — ■ 



Pinus longifolia between 2,000 to 5,000, and locally to 

 7,000 feet. 



Cedrus Deodara between 4,000 and 10,000 feet. 



Pinus excelsa between 4,000 and 11,000 feet. 



Picea Morinda between 6,000 and 10,000 feet. 



Abies Webbiana between 7,000 and 11,000 feet. 

 These conifers are generally associated with oaks, of which — 



Quercus incana is found between 2,000 and 6,000 feet. 



Quercus dilatata is found between 6,000 and 8,000 feet. 



Quercus semecarpifolia is found between 8,000 and 1 1,000 feet. 

 Then follow Betula Bhojpatra, and Juniperus Wallichimia up to 

 14,000 feet. Other trees found in this zone are species of Acer 

 Msculus, Buxus sempervirens, Juglans regia, Populus ciliata, 

 Cypress and Yeiv. 



The above-mentioned trees generally reach perfection in the 

 centre of their elevation, and they gradually fall off in vigour 

 towards the upper hmit of it. Spruce and silver fir are 

 frequently mixed, but they are also gregarious, while Quercus 

 semecarpifolia is nearly always so. Pinus Gerardiana is found 

 in the inner hills to which little rain penetrates. 



In the eastern Himalaya, in Sikkim, with its heavy rainfall, 

 oaks, chestnuts, magnoUas, laurels and tree rhododendrons are 

 the prevailing species over 4,000 feet elevation ; above 9,000 feet 

 they are replaced by numerous dwarf rhododendrons. Pinus 

 longifolia is found in Sikkim at moderate elevations in valleys, 

 and Abies Webbiana at high elevations up to 12,000 feet. In 

 Bhutan, Pinus excelsa is found, also Picea Morinda. At high 

 elevation in Sikkim Tsuga Brunoniana and Larix Grijfithii are 

 found. Pinus Khasya is found on the Assam hills. 



In the Burma hills Pinus Khasya is found from the Assam 

 frontier to the Southern Shan States at elevations of 2,000 to 

 7,000 feet, gregarious at the higher elevations, and often mixed 

 with deciduous trees on lower elevations. Pinus Merkusii is 



