ACACIA 421 



moisture in the soil and subsoil, for in this respect the babul is exacting. 

 Shallow soils with underlying sheet rock or beds of kankar have a stunting 

 effect : on such ground the kauria usually replaces the telia variety where 

 both occur, and the same applies to saline soils. The capacity of the babul 

 for existing on saline soils appears to depend on the presence of a considerable 

 amount of moisture in the soil. In Sind it cannot exist for any length of 

 time on saline soil, but here this soil denotes a failing water-supply, a condition 

 which is unsuitable for the growth of the tree in the dry climate of Sind. In 

 Berar, according to Mr. Shrinivasulu Nayadu,^ ' the existence of soda salts to 

 a large extent in the soil favours the growth of babul and its few associates 

 to the exclusion of other trees.' Many of the saline tracts, however, are on 

 the alluvium along the Purna river, where there is a considerable amount of 

 moisture in the soil. That the babul can actually flourish in salt water, and 

 that absence of soil moisture rather than salinity is probably the main reason 

 for its failure to grow on dry saline soils, is indicated from the following quota- 

 tion from the Madras Forest Report for 1909-10 : ' The experiments conducted 

 in Lower Godavari and Kistna for promoting babul growth on the saline soils 

 have not been successful, but inspection showed precisely the defects. In 

 Lower Godavari the area was blank ; it was evident that the water ran off 

 almost at once. In Kistna the area was on a slope, the upper part blank, 

 the lower part and hollows filled with babul seedlings, some of which, only 

 one or two years old, were 5 ft. or 6 ft. high. It is evident, then, that if the 

 water can be retained for some time, until the roots reach moisture level, 

 babul will succeed. Nor is fresh water necessary below, for babul was found 

 flourishing with its roots in perfectly salt water creeks.' The same is observable 

 along brackish creeks near Bombay, where the tree is seen in close proximity 

 to mangrove species. 



Type of forest. Acacia arahica is a typically gregarious tree, forming 

 crops which are pure or in which it is usually the most prevalent species. 

 It is a strong light-demander, and the crops come up in even-aged groups 

 or patches of varying extent. Forests of Acacia arahica are frequently termed 

 babul bans and sometimes babul meadows, the latter term referring to the 

 grassy midergrowth so prevalent in forests of this species. Its companions 

 vary in different localities : these, together with its mode of occiu'rence, can 

 best be dealt with for different localities separately. 



Sind. Sind contains by far the most extensive babul tracts in India, 

 the area of babul forest being roughly estimated at 172,000 acres, though this 

 area is subject to constant change owing to river action. The babul tracts 

 are situated on both banks of the river Indus. The distribution, and indeed 

 the existence, of the babul in Sind is governed by this river and its effect on 

 the soil moisture, for climatically Sind is unsuitable for the growth of babul. 

 In the regions where the tree is found the absolute maximum shade temperature 

 varies from 116 to 122 F., and the absolute minimum from 30 to 40 F., while 

 the normal rainfall varies from 3 to 10 in. Under ordinary circumstances it 

 would be impossible for the babul to exist under rainfall conditions such as 

 these, and it is to the annual inundations of the Indus that the babul forests 

 owe their origin and existence. The influence of the rainfall is of small 



1 Ind. Forester, xxxv (1909), p. 493. 



