Now some months after the National Koala Conference, I happened to come across the OE&H’s power point presentation titled “Koalas, Fire Management & Habitat Rehabilitation in SE NSW”. Not surprisingly for coastal koalas the two issues referred to are fire and getting preferred feed trees to germinate and grow.
The issue with fire was the Strategic Fire Advantage Zones (SFAZ) because they overlapped with areas occupied by koalas. The solution is to burn around known koalas and greatly increase the areas to be burned. Despite this approach the OE&H suggest there is room for the population to expand.
On the feed tree issue, some 28 locations have been chosen to trial regeneration techniques, as indicated in the table below.The treatment referred to as pruning appears to involve cutting down all the forest oaks and laying them across the slope. The approach would seem to confirm the OE&H is repeating the mistakes made trying to grow primary feed trees. In particular, a belief that the reduction of soil pH and associated decline in soil fertility, plays no part in tree germination, growth or koala survival.
The story is quite different in the northern hemisphere, where forest managers are concerned acid rain, in addition to logging has had similar negative impacts on forests. The USDA Forest Service for example, supports the Hubbard Brook Ecosystem Study in New Hampshire. One of the experiments involved a helicopter dropping 40 tons of wollastonite, a naturally occurring calcium silicate, onto a small ‘watershed’.
The outcomes have been very positive and arguably well worth a try in Australia, when forest managers are required to consider and act on science.
The NSW Department of Primary Industries has recently released a report titled ‘North Coast Residues -A project undertaken as part of the 2023 North Coast Forestry Project ‘. The executive summary indicates ” The main purpose of this project was to determine the potential availability of forestry residues for bioenergy generation and other applications on the North Coast of NSW . . ”
With regard to residues from public native forests the authors suggest ” . . .The values assume that a substantial proportion of the biomass (typically at least 20% of the total biomass) is left in the forest after harvest. ” The DPI then provide estimated volumes of residue that are, in all cases, greater than 200% of the biomass removed during harvest.
There is also a section titled ‘Extraction of biomass for bioenergy from NSW North Coast regrowth native forests: impacts on nutrient availability’. Regrettably the authors indicate ” . . . However, this study does not constitute a full nutrient budget that would also take into account temporal and below-ground conversion dynamics, and natural nutrient inputs (e.g. via rainfall). ”
Such a short fall essentially renders the generally repetitious information useless. This is particularly the case given the proportions of nutrients found in leaves, bark, branches and wood are not considered in terms of the actual volumes exported from forests during logging. In addition four of the references are not to be found and the only reference to calcium (Marschner, H. 1986. Mineral nutrition in higher plants. Academic Press London), is unlikely to apply to the north coast or Australian forests generally. On a positive note the authors suggest a move away from post logging burns, so some of the nutrients can be retained.
Also on a positive note is the news that Friends of Leadbeaters possums have stopped logging 34 forests in the Victorian central highlands. The Federal court’s decision, on whether the EPBC act should apply to logging nationally endangered species habitat, may have implications for all Regional Forest Agreement areas.