358 Travsactions. 



much of the easterly rain. This district therefore reproduces largely the 

 flora of the Lyttelton Hills, but, having a southerly aspect, no doubt is 

 neither quite so hot nor so dry as they are. 



Snow falls every year on the hilltops, and on Mount Herbert usually 

 lies for some weeks, but at the base of the hills it does not often fall, and 

 usualh' does not lie for more than a few hours. Tlie winter of 1918 was 

 exceptional, when snow fell to a depth of 10 in. even at the foot of the 

 hiUs, and the conditions above 1,000 ft. were truly alpine. Such falls do 

 much damage in the forest in breaking down trees and branches, though 

 but little permanent harm results if frosts do not follow. 



Next to the rainfall and temperature the most important climatic factor 

 is the wand. The prevailing wind is from the north-east. This in summer- 

 time is usually a sea-breeze, and then brings no rain, but when part of 

 a cyclonic system it frequently biings continuous though often light rains 

 lasting over many hours. The north-east wind passes into the north-west 

 wind, which is much less frec[uent, and is hot and dry. Only on the rarest 

 occasions does it bring a scanty shower of rain. It has, as will be seen 

 later, a most important effect on the distribution of the plants within the 

 area. The south-wester is a cold, wet wind, bringing much rain, and deter- 

 mines largely the vegetation on tlie cliff-faces exposed to the south. The 

 south-easter is, on the northern side of the peninsula, a somewhat rare wind, 

 of a gusty character — often stormy and occasionally bringing heavy rains. 

 It is often deflected as an easterly or north-east wind. The higher rainfall 

 of the outer portion of the peninsula is largely due to it. 



The rainfall is very irregular in its distribution over the year. The months 

 of December to March are usually dry, but exceptions occur. During this 

 period droughts are not uncommon, particularly on the north-west faces of 

 the peninsula, and often affect the vegetation. This has tended to produce 

 a distinctly xerophytic type of vegetation on the Lyttelton Hills, though 

 elsewhere it tends to the mesophytic. 



Changes in the Plant Covering. 



It has already been stated, and cannot be too strongly insisted on, that 

 here — as in so many other places in New Zealand — we are dealing with a 

 vegetation that has during the last seventy or eighty years undergone, 

 and is still undergoing, immense changes. The greatest of these is, of 

 course, the disappearance of the forest. Captain Thomas, Agent for the 

 Canterbury Association, reporting on the 15th May, 1849, estimated that 

 half of the area of Banks Peninsula — viz., 134,000 acres — was forest ; but 

 this probably was an underestimate, as nearly two-thirds of the peninsula 

 must have laeen forest-covered. Now there is probably nowhere on the 

 peninsula a stand of 300 acres of timber-trees, although there are larger 

 areas of the smaller bush trees, as in the forest at the back of Mount 

 Herbert. The reserves at Peraki Saddle, including some 167 acres, perhaps 

 contain the best specimen of primitive forest now to be seen on the 

 peninsula. Though there are equally fine trees near the L}^teltou-Kaituna 

 saddle, yet here the undergrowth has to a large extent been destroyed by 

 stock. It is unfortunate that what up till recently was the finest forest 

 on the peninsula— viz., the one at Stony Bay — is now being cut out by its 

 owners. Kennedy's Bush Reserve, near Christchurch, unfortunately con- 

 tains few trees of any magnitude, and its former wealth of tree-ferns has 

 been completely destroyed. 



