Introduced animal effects and erosion phenomena in the Northern Urewera forests

Authors: F.P. Wallis, I.L James
Publication: New Zealand Journal of Forestry, Volume N.Z.J.For. 1972, Issue N.Z.J.For. 17(1) 1972, pp 21-36, May 1972
Publisher: New Zealand Institute of Forestry

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Abstract: The northern Urewera forests provide major indirect benefits to most of the eastern Bay of Plenty farmlands and towns through control of erosion and water runoff on the steep unstable mountain land that occupies 75% of the Whakatane and Waioeka River catchments. Recent assessments in this forest region show that there has been a depletion of deer preferred species and a depression of advance growth stockings throughout the main forest types. A decline in deer numbers, attributed mainly to recent animal control operations, appears to be effecting an improvement in beech and podocarp-hard-wood forest stockings. Where opossum numbers are high, their damage to shrub hardwood forest occupying unstable sites is considered to have increased shallow depth earth movements and stream channel erosion. Major slipping in the region is associated with the high intensity rainstorms, steep slopes and soil physical properties.

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