A study of the Exotic Conifer Plantations on Rhyolitic Pumice at Kaingaroa, New Zealand

Abstract

Kaingaroa is one of the "gently sloping high land surfaces, conveniently called plateau" Grange, 1937, p.16), extending between 176° 15' - 176° 40' Long. and 36° 2o' - 36° 50' Lat. in the Rotorua-Taupo district (photos 1 ,2, 3 and 4 ). It is part of a great area, 18,800 square miles in extent, in the centre of the North Island of New Zealand covered by Taupo ash and pumice, i.e. aerially deposited material forming unconsolidated beds of a lumpy and sandy pumiceous nature. The distribution of this ash shower is shown on photo 90 derived from a small scale map attached to the Bush sickness Bulletin (1932) Pond and Maclaurin, as far back as 1900, wrote about Kaingaroa: "It is impossible to traverse this vast plain with its almost interminable monotony of pumice sand and stunted vegetation, without wishing that it had been a rich basic instead of a poor acidic soil, without wondering whether it is not capable of some treatment which would at least make it of more value for grazing purposes than at present, by the herds of horses that roam at large or the hares which nave made their homes on the plains." They caried out chemical and mechanical analysis of the soil to investigate a possible utilization.