Chat. Ill] TROPICAL WOODLAND AND GRASSLAND 27.5 



RAINF'ALL IN MILLIMETERS OF THE IIIGH-FOREST 

 IN MINAS GERAES. 



CONGO SOCO. 



19' 58' S., 43" 33' W., 1,090 meters above sea-level. Two years' observations. 

 (After Draenert in Meteorol. Zeitschr., 1S86, p. 390.) 



Dec. Jan. Fcl). M.ir. .\i)r. May June July -Vug. .Sept. Oct. Nov. Year 

 369-6 604-3 537-7 253-0 172-0 57-9 55-1 34-0 20-3 93-2 169-7 573-5 2939-3 



The climate, however, is not so unfavourable for tree-growth as to 

 Drevent small xerophilous savannah-trees from establishing themselves 

 n the prairie and thus lending to it the character of a savannah. At 

 he points where water is more plentiful in the soil, where the winds 

 3I0W less strongly especially during winter, where atmospheric humidity 

 s greater, woodland prevails over grassland, so that the whole district 

 hows the alternation of both formations in its park-like features. 



In contrast zi'ith its sonthcrn portion, tlic middle part of Central Brazil, 

 he so-called Sertdo district, possesses a xerophilous ivoodland climate. 



Here the year is hot throughout, at times very hot, and there are no 

 Iry cold winter months that are so inj'urious to woodland ; on the other 

 land, the climate includes factors unfavourable to grassland in the more 

 onsiderable heat and the small amount of precipitation over the greater 

 lart of the district, except the coast. Finally, the vegetative season is 

 nuch interrupted by hot dry periods. 



The Sertao district is therefore much richer in woodland than is the 

 outhern cooler campos district. Tree-growth is richer in the savannah, 

 xtensive tracts are covered by savannah-forest and thorn-forest, in general 

 .•Qodland strongly predominates over grassland. To explain in detail 

 .'hy woodland occurs in one place, and why grassland in another, is at 

 'resent only partially possible, for there is a lack of accurate data of the 

 leteorology and local constitution of the soil, and the soil plays an 

 Tiportant part in such mixed districts^. 



Quite a narrow strip of coast in the province of Pernanibuco possesses a verj- 

 eavy rainfall, a real high-forest climate (Pernambuco, 297 cm.). Tree-growth is 

 xtremely lu.\uriant in the public grounds of the principal town, but there is no 

 iformation available regarding the indigenous vegetation. 



' See Part III, Sect, I, Chap. V. 



T 3 



