Management options for Australian Blackwood (Acacia melanoxylon) in Southern Cape Forests, South Africa: management paper

Abstract

Australian Blackwood (Acacia melanoxylon) was actively introduced into the indigenous forests of the southern Cape until about 1930. On the perception that this exotic species constituted a threat to the indigenous forest, a policy of eradication was followed. This perception that Blackwood is capable of progressively replacing the native biota was questioned periodically. Recent investigations support the contention that the species is subject to constraints to its effective self-replacement within the indigenous forests. In the context of a policy re-evaluation, it is recommended that in the medium-term and until monitoring has provided clarity on outstanding issues, the control programme be restricted to areas where exotics are inherently unacceptable, as is the case for nature reserves. Two harvesting options for the remaining old-growth Blackwood timber in the forest are presented. According to the short-term depletion harvesting option, ca 2000 m3 of timber can be harvested annually until the year 2003. The medium-term optimisation option makes provision for annual harvest of 1500 m3 until 2010. Particularly in the case of the second option care must be taken to harvest the more senile trees early in the sequence if an acceptable degree of mortality pre-emption is to be achieved.


Southern African Forestry Journal No.196 2002: 55-66