The Planned Production Period for Short Rotation Eucalyptus grandis

SYNOPSIS

The various criteria for determining rotation length in forestry are reviewed briefly and the short rotations of Eucalyptus grandis in South Africa are scrutinized against the criteria for maximum yield, maximum income, maximum internal rate of return and maximum turnover. Mean annual timber volume increment did not culminate before 11 years and the culmination was not only dependent on site quality but also on stocking density which counteracts the effect of site. Maximum turnover criteria gave the identical results to those for volume yield when prices did not increase with timber size. Net annual income did not culminate before 12 years under present price and cost structures. The profitability of average short-rotation E. grandis is relatively low and the maximum internal rate of return usually is not obtained before 11 years. It is concluded that the rotation length for short-rotation E. grandis in South Africa is generally too short and that longer rotations will improve profitability and cash flow considerably.