:234 PLANT SUCCESSION. 



■ clear when a smaller area is studied more intensively. Thus, in- 

 Natal alone, quite a number of distinct types of Tree Veld, as 

 well as local variations of each type, occur. Of these by far the 

 most extensive is the Thorn Veld, in which the succession has 

 alreadv been analysed in detail by Professor Bews (4). Other 

 types which have been briefly described by the same author are 

 the Protea Veld, the Rocky Scrub with Greyia Sutherland I 

 dominant, and the Leucosidea scrub of the Drakensberg (5); the 

 Rocky Hillside type of the Midlands (2) ; and the various types of 

 Tree Veld of the Coast- belt, e.g., Ilala-Palm Veld and hygro- 

 philous Tree Veld (6). Very often these types occur mixed with 

 the more xerophytic Thorn Veld, but usually they are quite dis- 

 tinct. A good example of this is the Ilala-Palm Veld, which 

 covers large areas of the Zululand coa«t-belt (7). Where it occurs 

 in proximity to- Thorn Veld the palms often extend for some dis- 

 tance into the latter, particularly if the thorn trees are very 

 scattered. 



All these types of Tree Veld, though differing greatly from 

 one another in their composition, have one remarkable feature in 

 common, a feature which is quite unique — the invasion of grass- 

 land by treesi in the first stage of the succession. Tree Veld has 

 usually a very characteristic, park-like appeal ance, due to the 

 formation of scattered clumps of trees and bushes in the grass- 

 land. The actual pioneer in the formation of these clumps varies 

 according to the type of climax association, but is always a tree. 

 In some cases the succession proceeds no further than this first 

 invasion of the grass-veld, e.g., Ilala-Palm Veld, but as a rule 

 other species succeed the pioneer and grow up in its shade, forming 

 the mature clump. The only detailed account of the complete 

 process so far given is that of Professor Bews on the succession in 

 the Thorn Veld (4). Yet in view of the widespread occurrence 

 of Tree Veld in South Africa and of this unique feature in its 

 establishment, it is very desirable that as marry facts as possible 

 should be gathered with regard to the various types, and the suc- 

 cession in each. 



The present paper is intended to give an account of the suc- 

 cession in a type of Tree Veld, which may be termed a Cussonia- 

 Combretum association. It shows some resemblances to the Rocky 

 Hillside type, already mentioned, from which, however, it appears 

 to be quite distinct. It occurs on the northern slopes of Signal 

 Hill, situated just outside Maritzburg proper and to the south- 

 west of the town. (PI. II, Fig. 1.) No details can as yet be given 

 as to the distribution of this type, but it is probably fairly common 

 on hillsides throughout the Midlands. 



II. Topography and Climate. 



A panoramic view of practically the whole area studied can 

 be very well obtained from any point near the summit of the hill. 

 From such a vantage point one looks down upon an undulating 

 stretch of grassland sloping gently upwards. Almost through the 



