TROPICAL WOODLAND AND GRASSLAND 261 



besides these, transitions are very frequent between savannali-forcst and 

 savannah as well as between thorn-forest and open busli-formations, 

 ivhich as intermediate forms connect the formations of woodland and 

 desert. 



Tropical grassland, wherever it has not been modified by human agency, 

 :)ccurs chiefly as savannah, more rarely as sicppc. The occurrence of 

 ')icadinv, by which we understand hygrophilous or tropophilous grassland, 

 s rare in the tropics and is always due to factors that arc merely local. 



Tropical desert has a vegetation consisting of scrub, that is to say, 

 jf stunted trees and shrubs or of shrubs only, also of succulent plants and 

 Derennial herbs. Most tropical deserts are near the tropics of Cancer 

 uid Capricorn, and are allied to the far more extensive warm temperate 

 leserts. The climate of the tropical deserts will be treated of in a subse- 

 juent chapter together with that of the temperate deserts. 



2. HIGH-FOREST CLIMATE IN THE TROPICS. 



Brandis declares that really succcssfnl forests occur only w/ierc tlic rainfall 

 itaiiis forty inches, and that a luxnriant rich vegetation is limited to zones 

 vlierc the annual rainfall is vinch greater. 



The available meteorological tables for tropical districts show, in regard 

 o land that is covered with or has been covered with high-forest (rain- 

 orest or high monsoon-forest), an annual rainfall of at least iHo cm., 

 xcepting near large sheets of water where telluric moisture replaces 

 ain. Within the most extensive forest-district of the tropics, the Indo- 

 ilalayan, including New Guinea, an annual rainfall of over two meters is 

 he rule ; wherever much less than two meters of rain falls, the indigenous 

 egetation, so far as is known, forms less lofty woodland, as at many 

 pots in East Java, or creates savannah, as in Timor (Koepang in Timor 

 as a rainfall of 145 cm.). On the other hand, at many spots the rainfall 

 xceeds 300 cm. ; at several it exceeds 400, at Buitenzorg, for instance, 

 saching 499 cm. 



Thanks to the excellent records of the numerous meteorological stations in Dutch 

 lalaysia, Woeikof ' has been able to compare the conditions of rainfall of a great 

 umber of localities there. In Java the annual rainfall is given for 62 stations ; it is 

 ;ss than 200 cm. for twelve of them only, for five it is less than 150 cm., for none is it 

 ;ssthan 100 cm., the minimum (113 cm.) being at Probolinggo. Several of the above 

 jcalities are known to me personally, for instance Probolinggo, where the rainfall is 

 nvest. Probolinggo is in East Java, far from any forest, and there, except man- 

 roves, I found in the wild state onlj' thorny brushwood, xerophilous in character. 



he vegetation near Pasoeroean, where the rainfall is quite as small, is just like that 

 f Probolinggo. It cannot now be ascertained what kind of indigenous vegetation 



rmerly occupied these parts of the countrj-, which are now covered with planta- 



' Woeikof in Zeitschr. d. o5terr. Gesellsch. f. Meteorol., 18S5. 



