62 JOURNAL OF THE ARNOLD ARBORETUM [vol. iv 



both north and south of the equator. Of the Conifers the genus Libocedrus 

 is represented in California by Libocedrus decurrens Torr., in Formosa and 

 southern China by L. macrolepis Benth. & Hook. f. and by six other species 

 south of the equator of which two grow in South America, two in New 

 Zealand, one in New Caledonia and one in New Guinea. One species {Juni- 

 perus procera Hochst.) of the characteristic northern genus Juniperus just 

 crosses to the south of the equator on the highlands of Kenya Colony in 

 central Africa. Of the tropical genus Agathis one species (Agathis alba 

 Foxw.) is found in Malaya and the Philippines while the others grow 

 south of the equator, one of these (A. australis Steud.) being the famous 

 Kauri Pine indigenous in northern New Zealand. Of Taxads several 

 species of the cosmopolitan genus Podocarpus are found north of the 

 equator and two of them {Podocarpus macrophylla D. Don and P. nagi 

 Zoll. & Moritzi) occur as far north as southern Japan. The genus Dacry- 

 dium belongs principally to the southern hemisphere but is represented 



Wall 



D. Bcccarii Pari. 



FOREST WEALTH AND FOREST PROBLEMS 



Before proceeding further it is advisable to say a few words about the 

 forest wealth and forestry problems of these southern lands. Africa 

 south of the Zambesi River is high level country except a narrow broken 

 coastal fringe. On these highlands forests, as we understand the term, 

 do not exist. The trees found there are low-growing with short boles 



and occur in open park-like formations. All are hardwoods of little 

 value. In the broken coastal fringe in parts of Natal, Zululand and the 

 Cape Province there are belts of dense forests where grow a variety of 

 useful timber trees. Among them are three species of Podocarpus (Podo- 

 carpus latifolia R. Br., P. falcata R. Br., and P. Henkelii Stapf which 

 furnish softwoods of great value. Unfortunately these and the best of the 

 hardwoods occur scattered through the forests and their exploitation is both 

 wasteful and expensive. The best and most accessible of these trees have 

 been removed. Apart from the three species of Podocarpus referred to 

 the only other softwood trees are various species of Widdringtonia of 

 which few grow to any size but their wood is imperishable in the ground. 

 To meet the increasing requirements of a growing population South 

 Africa needs trees for timber and also for shade. The imperative necessity 

 of tree planting is now being recognized. It has been found that the 

 indigenous trees are of very slow growth compared with certain exotic 

 species and forestry in South Africa simply means tree-planting and the 

 conservative exploitation of such forest remnants that exist. As will be 

 shown later soil and climate in many parts of South Africa seem favorable 

 to tree growth and a number of exotics flourish in a remarkable manner. 

 Australia is a continent in every respect and an arid central zone divides 

 it naturally into western and eastern halves. Much of West Australia 



