Slash burning-its implications for 20-year height growth of eucalypt regeneration in Tasmania

• Published in: Australian forestry 1998-01, Vol.61 (2), p.159-162
• Main Author: Lockett, E. J.
• Format: Article
• Language: English
• ISSN: 0004-9158; 2325-6087
• DOI: 10.1080/00049158.1998.10674734

Height data to 20 years are presented for a study previously reported by Lockett and Candy (1984) on the effects of slash-burning on growth rates of eucalypt regeneration established following clear-falling. The study covers a range of forest types on five sites throughout Tasmania with rainfalls ranging from 800mm to 1800mm. On the two driest sites, the initial conclusion that slash burning had no significant impact on height growth has been confirmed by subsequent measurements. On the three wetter sites, there was a consistent trend which suggests that slash-burning caused growth rates to be more than doubled in the third year post-burn. This effect progressively declined and finally disappeared between years ten and fifteen. The net result of burning would be a shortening of the rotation by a maximum of five years, or less where natural regeneration is already established, or can be established earlier in the absence of a slash-burn. Operationally, the decision whether to burn or not will involve balancing these growth effects against the stocking, size and potential vigour of new natural regeneration or older advance growth and the desirability of preserving it. This may require consideration of how difficult it is to establish regeneration on the site and how much the risk of wildfire will be increased if slash is left unburnt.