New Zealand Journal of Ecology (2002) 26(1): 73- 79

Rapid recovery of kohekohe (Dysoxylum spectabile) following possum control

Short Communication
Graham Nugent 1,*
Jackie Whitford 1
John Innes 2
Kevin Prime 3
  1. Landcare Research, P.O. Box 69, Lincoln 8152, New Zealand
  2. Landcare Research, Private Bag 3127, Hamilton
  3. Motatau, R.D. 4, Kawakawa
*  Corresponding author

We document the rapid recovery of kohekohe (Dysoxylum spectabile) canopy cover following the control of brushtail possums (Trichosurus vulpecula) in Motatau Forest, Northland, New Zealand. Possum trapcatch rates were reduced from 25.6 ± 14.9% (mean ± SE) in 1997 (prior to control) to 2.7 ± 3.1% in 1999, but were little changed in Okaroro, an uncontrolled area nearby. Mean canopy cover scores for kohekohe in Motatau increased from 16.1 ± 4.5 % in 1997 to 52.6 ± 5.2% in 1999, but increased far less at Okaroro, from 42.3 ± 6.3% to 48.0 ± 7.75%. Changes of a similar nature, but of a much smaller scale, were recorded for four of the five other species monitored. For all six species combined, the increase in canopy cover at Motatau was much greater for the trees most heavily browsed initially, but there was no such pattern at Okaroro, further confirming that at least part of the observed increase in canopy cover was a response to the removal of possums.