Laing. — Vegetation of Banks Peninsula. 359 



Agents altering Plant-distribution. 



The primitive plant covering, then, has largely disaj)peared, and has 

 been replaced by introduced species, particularly by grasses ; the balance 

 in the remaining plant associations has been altered, and the conditions 

 under which many of the species live are quite changed. Probably the 

 grasslands of the Lyttelton Hills have been less altered than the forests 

 of the peninsula, for the tussock form still dominates ; yet here certainly 

 many changes have taken place and others are still in progress. The chief 

 destructive agents at work where cultivation has not been employed are 

 continual tussock-fires, bush-fires, drought, sheep, cattle, on the I^yttelton 

 Hills rabbits, and on Banks Peninsula hares. 



On the grasslands the tussock-fires make for the extinction of the ferns, 

 for the reduction in the number of the species, for the replacement of certain 

 grasses by others, for the destruction of isolated shrubs, and for the multi- 

 plication of a fcAv plants that can to some extent withstand the action of 

 fire — e.g., Coriaria sarmentosa. 



On the other hand, bush country when burned and allowed to restock 

 itself reproduces the usual fire weeds ; but these are seldom or never allowed 

 to remain, being either destroyed by the hand of man or replaced in old 

 burns by Pteridium esculentum or species of Leptospermum. These changes 

 however, will be considered in greater detail under the various plant 

 formations. 



It may, however, be noted here that in all the inoister bays of the 

 peninsula — that is to say, from Port Levy eastward and southward to 

 Akaroa- -cocksfoot (Dactylis glornerata) was sown on the burnt areas, and 

 the result has been the development of an artificial plant association. After 

 the first sowing this grass has replaced itself in a remarkable way, and 

 though reaped for forty or fifty years has continued to produce crops of 

 almost undiminished vigour. Largely owning to the scarcity of casual labour 

 the cocksfoot harvest is now becoming a thing of the past, and dairy- 

 farming is to a large extent replacing it. 



The cattle are grazed on the cocksfoot, which is the chief ingredient 

 of the pasture lands, though rye-grass {Lolium perenne), timothy [Phleum 

 pra(ense), and crested dogstail {Cynosuras eristatns) are also to be met with 

 in smaller quantity. Sheep are to be found chiefly on the tussock areas, 

 though even on the cleared forest areas they are in many places being 

 stocked in increasing numbers, owing to the smaller amount of labour 

 involved in looking after them. Further discussion of these economic 

 matters would, however, be out of place here. 



The changes due to the action of animals on the vegetation, though 

 extensive, are not so wide-reaching as those of fire. Sheep cro]) certain 

 grasses, and thus prevent them seeding. They also attack other species 

 of plants, such as Angelica nwntana, Carmichaelia suhulata, and even the 

 young spinous leaves of Aciphylla squarrnsa. On the other hand, their 

 function in the spreading of ])lants by means of seeds can hardly be over- 

 estimated. The large increase in danthonia {Danthonia pilosa) referred to 

 farther on may be cited in this regard. Other species spread by the 

 same means are Urfica urens, Acaena novae-zelandiae, and Marnihium 

 ruhjare (white horehound). Cattle, again, are probably entirely destructiv(\ 

 Phormium soon disappears in their presence, as also does Marrubium. In 

 Pigeon Bay, for example, the upper portions of the hills are in many places 

 grey with horehound, whilst the cattle-country immediately below is perfectly 

 clear. Uiifortunately, cattle will not run in the rocky, broken country on 



