518 Transactions. 



Art. XLIX. — Effects of the Snowstorm of the 6th September, 1916, on the 



Vegetation of Stewart Island. 



By Walter Traill. 



Communicated by Dr. Charles Chilton, C.M.Z.S. 



[Read before the Philosophical Institute of Canterbury, 6th December, 1916 ; received by 

 Editors, 30th December, 1916 ; issued ssparately, 10th December, 1917.] 



On the 6th September, 1916, there occurred a particularly heavy snowstorm 

 in Stewart Island, which caused considerable damage to many of the 

 indigenous trees and shrubs, and the following particulars are perhaps 

 worthy of being placed on record. 



The weather of Stewart Island on the 6th September was very unusual. 

 The first part of the day there was heavy rain for about seven hours, with 

 little wind. About 10 p.m. the rain stopped, and a calm followed, with a 

 dense fall of snow. The temperature was then about 50° F., and during 

 the night it kept comparatively mild and warm, but towards dawn the sky 

 cleared, and although still and absolutely calm it became bitterly cold. 

 During this cold spell there could be heard, in the forest, trees and branches 

 crashing down. As the sun appeared the sky again became cloudy; a 

 light W.N.W. wind sprang up ; the temperature rose to about 53° F., and 

 the snow, which was about 5 in. deep, began to melt very fast — i.e., near 

 the sea-coast and on beaches. By the evening about 2 in. of snow was left 

 on the open land. The rainfall, including the snow, for the 6th was 3'68 in. 



In the coastal scrub the tree most affected was Senecio rotundifolius ; 

 then, much less so, Dracophyllum longifolium, Coprosma spp., Nothopanax 

 Colensoi, and large-sized manukas (Leptospermum scojmrium var.). Olearia 

 Colensoi, 0. arborescens, and 0. angustifolia do not appear to have suffered 

 at all, nor the veronicas (V . elliptica, V. salicifolia var. communis) ; but 

 fuchsias {Fuchsia excorticata), although bare of leaves, suffered a good deal. 



Of the trees and shrubs from other places planted on the section at my 

 residence on Ulva Island, Senecio Huntii, Olearia Traversii, Coprosma 

 robusta, C. grandifolia, and Arbutus unedo suffered badly; but the pines 

 (Pinus radiata), larches, spruces, yew, &c, were not damaged at all. The 

 six specimens of Brachyglottis repanda planted here, and now of large size, 

 also escaped damage, a remarkable circumstance considering the great size 

 of its leaves and its brittle twigs. In the forest the miro (Podocarj)us 

 ferrugineus) lost far the most branches, but few whole trees were down. 

 Rimu (Daorydmm cupressinum) comes next: quite a number were up- 

 rooted, and branches were hanging from others in all directions. Rata 

 (Metrosideros lucida) and kamahi (Weinmannia racemosa) did not suffer 

 so badly as the rimu, and totara (Podocarpus Hallii) seemed to stand the 

 weight of snow fairly well ; but a number of all the larger trees in the forest 

 on Ulva were uprooted. In some instances flood-water covered the ground 

 around their roots. The cabbage-tree (Cordyline australis) had all the outside 

 leaves bent down ; but this will not matter, as new leaves will soon form. 



The Government tracks on Ulva are now cleared, and I got one of the 

 men to help me on the section. We removed nearly a cord of firewood from 

 branches on the tracks within a radius of about 5 chains, and this should 

 give an idea of the average fall of branches, whole trees being omitted. 



The old Natives here say there is no record among them of such 

 damage to the trees by snow as the present one. I may mention that 

 a few days before the snowstorm thousands of kakas and pigeons arrived 

 at Ulva, and many are still here. 



