



From an altitude of 1,500 ieet upwards a tall 

 Casuarma is common. This is C. nodi flora G. Forst., 

 but must not be confounded with 0. equiselt folia, which 

 is a purely beach forest species. 



Another large tree is Diptanthera teiraphylla. This 

 is a handsome wide-crowned tree with showy yellow- 

 flowers in terminal panicles. 



A number of small trees and shrubs make up the 

 woody plant formation, and among them is a sandal- 

 wood, Santalum sp., at the lower levels. Mori ft da 

 citrifolia is common, but this at Hombron Bluff and 



assume more of the rain forest characteristics. Aerial 



gardens of epiphytes clothe the branches of the larger 

 trees, many more rain forest types have intruded, large 



lianas begin to be a striking character, and scitaminous 



plants now form an undergrowth. Further inland the 

 savannah forests become mere islands in the ocean of 

 forest, which now assumes the definite rain forest 

 formation. But — and here I think is a subject of suffi- 

 cient interest for careful (ecological 



the dry sclerophyllous savannah forest of the Central 

 Division does not cease until the lower limit of the mist 



investigation' 



Warirata is replaced by Timoniu* rumphii. Some pretty bolt— 5,500 feet— is reached. Eucalyptus papuana, E. 



clavigera, and />'. alba do not occur, but K. tereticomis 



genus occur near the coast. grows in a closer formation at 4,500 feet than 



flowering verbena trees or shrubs of the Clerodendron 



at 



Between these trees and shrubs, which are scattered Bisiataba 1,<00 ieet. 



Cat 



vtiantia no 



dijh 



ra 



at some distance from each other, the ground is covered 

 with grasses, of which the two largest, if not the most 



common, are Kurakura (Imperata arundinacea Cyr., 



and Saccharum spontancnm Linn). These two tall 

 grasses appear to take possession of the ground wherever 

 it is open enough, and of the two Saccharum requires 



rather moister land. These grasses are conspicuous, bul 

 the many others — 43 gramineae are enumerated by Mr. 

 White' 1 > — are more numerous, particularly al higher 

 altitudes. Here and there in the grass a cycad (Cycas 

 media) is to be found, and this gymnosperm is so 

 numerous as to give character to the landscape. 

 Throughout the savannah forest of the dvy belt, gullies 

 and ravines exist which are clothed with a type of 

 forest intermediate between the rain and the 



is very 

 common, and the same cycad sprinkles the grass. When 

 the euealypts have been cut down for firewood or oilier 

 purposes, the regeneration is thick and vigorous. While 

 neither at low or niid-monntain altitudes do the gums 

 find their way into the heavier forests at 5,000 feet, 

 Casuarina nodi flora grows also in the rain forest, and it 

 a remarkable siffht to see this soeeies rearing ils 



is 



o 



aks. So 



entire 



savannah forests. 



lypts 



ram 



It carries a certain number of 

 deciduous trees, of which the kapok or cotton tree 



(Bombax malaharacum Do.) is perhaps the best example 

 ■ — a very large thick-barked deciduous tree which is a 

 beautiful sight when in flower, the large red blossoms 

 in the leafless branches making it very conspicuous. 

 Other deciduous trees also occur, and one- — uri of the 



Motuans, close to the Jfelias — grows both in the rain 



forest and the gullies of the dry belt. Another tree 

 which is found in both formations is devoru (A Is! on hi 

 scholar is), the Queensland milk wood, milky pine, or 

 white pine; a large asymmetrically-holed tree. Alhixxins 

 occur also, and one, mokeke (.4. procera) is confined to are the forerunners, if not the nurses of the true forest 



species 



trunk alongside hoop pines, podocarps, and 

 is it curious to see in the grass lands on I he edge of a 

 Tain forest the cycad growing, and close to it. perhaps 

 not 20 yards away, the tree fern in the shade of the 

 heavy timber. Were it not for the presence of large 

 and obviously very aged eucalvpts, and the 

 absence of all rain- forest or gully-forest species on ihese 

 highland dry-forest patches, I would feel some hesi- 

 tancy about calling them real savannah forests, and 

 might ascribe their origin to artificial causes. While 

 artificial savannahs are created by natives in the mid- 

 mountain forest regions, these areas do not carry euca- 



or casuarinas, and are only kept from reverting 

 to high forest by the annual fires of the hunters. When 

 the population has left a hill-top village, and moved 

 down to the valley — a procedure which is happening 



everywhere that the Government's influence has been 



felt sufficiently to stop inter-tribal warfare — the aban- 

 doned farm lands which were in the high forest show a 

 good regrowth of those light -demanding weed specie- 

 which I shall have occasion to refer to later, and which 



the damper places of the dry belt. The others seem 



to grow as well as in the rain forest. 



These gully 



fcrests seem to occur wherever the subsoil moisture is 

 sufficient to support hygrophyllous trees, and these 

 make up the greater part of the species of such associa- 

 tions. Wherever a gully forest is destroyed by natives 

 for farming purposes the original growth is replaced by 

 grasses, and little by little the eucalvpts and other 

 savannah forest trees become established. This is not, 

 I am confident, a natural succession, but is due to the 

 fires that the natives light in the grass lands in the dry 

 season for hunting purposes The young regrowth 

 species of the gully forests are killed at once by fire, 

 and grass is in consequence established. Only fire- 

 resisting species, like the eucalvpts and certain other 

 thick-barked trees — elerodendrons, for instance — can 

 then establish themselves in open forest formation. 

 Were if not for these fires the regrowth would be very 

 similar, if not the same, as the gully forest before the 



natives cleared it for fanning. There are certain areas 

 in this dry belt about which it is difficult to decide 

 whether they are artificial savannah forests, caused 



through the natives' farming and burning proclivities, 



or the real savannah forests. This is accentuated when 



the sire is not a gully or depression, and does not 

 appear to be particularly damp. In such oases T have 

 come to regard the presence of old devoru and other 

 trees that thrive best in the rain forests, but grow well 

 also in the gully forests, as a proof that the country in 

 question was once covered with the latter intermediate 

 formation. 



As the ground rises from the coast inland, the areas 

 of trullv forest extend more and more, and begin to 



(i) C. T. White, F.L.S.: 



Paj.M.n/' pp. 1 l-lfv 



■ I 



A contribution to our knowledge of the flora of 



species. Gully forests occur at 5,000 feet, which, while 

 differing in composition, are of the same tyj>e as those 

 that occur at 400 feet behind Port Moresby. 



Economically the only species of outstanding value 

 in the Savannah Forests of the dry belt of the Central 

 Division is the sandalwood. J deal with this source of 

 wealth in the section headed " Minor forest produce/ 

 To the baker, user of producer gas -pi ante and house- 

 holders, the euealypts of the Port Moresby hills are 

 of great value as a source of fuel and power. Tie 

 plantation manager is glad to make use of the round 

 logs of the narrow-leafed gum (K. teret icornis) for hifl 

 fence posts and house props, though he prefers melila 



(Afzelia bijuga) if he can get it. Where the soil is 

 sufficiently deep and moist no doubt it would be prac- 

 ticable to make plantations of more valuable species, 

 but on such sites species yielding fruit, rubber or other 

 tropical comparatively short rotation crops should prove 

 nationally more economical than timber producing 

 species. Tn the porous Port Moresby bed soils it is 

 doubtful whether any better species could be induced 

 to grow than the eucalvpts now occupying the ground. 

 The gullies must certainly remain the garden plots of 

 the natives, and, if the population increases, more and 

 more of such, or similar profitable, farming land must 

 he thrown open to them. 



Within the long strip known as the dry belt several 

 ar is of high rain for t occur. These are formation! 

 which owe their existence to tin- presence of ample 

 supplies of water in the -oil. They occur along the 

 1))^ and small rivers and extend inland on either side 

 for a distance which depends purely on the width ot 



alluvial soil the riwr has made-. Such formations only 



