On International Day of Forests it is essential that we recognise that forests support our civilisation, climate and biodiversity. Forests are under unprecedent threat due to increasing droughts, heatwaves, wildfires and floods. At the very time we need them to take our carbon out of the atmosphere and store it safely in their wood and soils, and to mitigate flooding by storing and slowing the water during extreme rainfall events.
Big old trees are awesome, hundreds of years old, towering 8-12 stories high, apartment complexes for hollow-dependent animals with larders for Koalas, gliders, possums and a multitude of honeyeaters.
Forests improve our health, generate rainfall, cool the land, regulate streamflows, sequester and store carbon, reduce flood risk by storing water and slowing flows, reduce landslips by reinforcing soils, and support most of our biodiversity.
The allocation of Crown land for conservation dates back to 1866 in NSW, with the first National Park created in 1879. Since then it has been a slow and tedious process to construct an effective reserve system in north-east NSW. NEFA was instrumental in achieving a doubling of reserves (See: A Short History of Reserves in North East NSW).
Reserves have been established for recreation, scenic qualities, heritage values, and flora and fauna conservation. It has been community agitation that has been primarily responsible for public land being set aside for conservation, with destructive uses such as logging, mining and grazing generally excluded.
Vested interests have led the fight against reservation of crown land for conservation. Historically they were successful in largely limiting reserves to the least productive areas with limited commercial potential.
In 1992 the National Forest Policy committed all Australian Governments to establishing Comprehensive, Adequate and Representative reserve systems for forests based on explicit national reserve targets (See: CAR Reserves). This was meant to be a way forward to ensure that reserves encompassed representative samples of all ecosystems and species while being of adequate size to maintain viable populations of flora and fauna into the future.
The process leading to the 2000 Regional Forest Agreement (RFA) for North East NSW did result in a significant increase in the reserve system in north-east NSW based on sound data and targets. Though unfortunately politicians once again bowed to pressure from vested interests and intervened to stop the promised CAR reserve system from being established (See: CAR Reserves).
Despite north east NSW’s forests being one of Australia’s and the world’s biodiversity hotspots, the reform process still left us with one of the worst forest reserve systems in Australia, and many of the national reserve targets unmet. There remains an urgent need to expand north east NSW’s reserve system to achieve the basic requirements of a CAR reserve system, particularly in light of the accelerating impacts of climate change.
Due to the conservation of more productive lands in recent decades, the vested interests are now campaigning to have reserves opened up for logging and grazing. The pretence is that they need to be logged for “ecologically thinning” and grazed for fire protection.
It is the bigger and older trees that provide resources in the abundance required by numerous animals. It may take a tree one or two decades before they begin to flower and set seed, which they produce in increasing abundance as they mature. Numerous species of invertebrates, many birds, and a variety of mammals feed on these flowers and seeds. As they mature their trunks and leaves also exude a variety of sweet substances used by many species. Invertebrates harbour within their rough and shedding bark where they are eagerly sought out for food. Yellow-bellied and Squirrel Gliders chew channels through their bark to tap trees for sap. As the trunks and branches thicken the trees provide more stable nesting and roosting sites, while enabling Koalas to hug them on hot days to keep cool.
Once a eucalypt tree is over 120-180 years old they may start to develop hollows in their branches and trunks. In NSW at least 46 mammals, 81 birds, 31 reptiles and 16 frogs, are reliant on tree hollows for shelter and nests. As the trees get bigger so do their hollows, and it may not be until they are over 220 years old that they develop hollows big enough for the largest species. Most eucalypts may only live for 300-500 years, though some are reputed to live for over 1,000 years(see The Importance of Old Trees).
photo: Dailan Pugh OAM
Crown of a Sydney Blue Gum (Koreelah SF) hundreds of years old showing the numerous broken branches and large hollows necessary for large-hollow dependent fauna
Natural forests may support 13–27 hollow-bearing trees per hectare, with numbers varying between species, and increasing on more productive, moister and flatter sites. On agricultural lands the numbers of hollow-bearing trees have been drastically reduced. Similarly they have been significantly reduced throughout the remnant forests by logging, prescribed burning and by culling in Timber Stand Improvement operations.
In State forests in north-east NSW logging prescriptions now require the retention of an average of 8 hollow-bearing trees per hectare within logging areas, though numbers have already been reduced below this level in many forests. Where retained, hollow-bearing trees continue to decline with each logging due to token implementation of prescriptions, poor tree selection, inadequate protection, damage during logging and in post-logging burns, and lax enforcement. (see Protecting Habitat Trees)
Natural forests are generally multi-aged, so that as existing hollow-bearing trees die and collapse there are new trees with developing hollows to replace them (see The Importance of Old Trees). To account for this, up until 2018 the logging prescriptions required the retention of an additional sound and healthy mature tree for each retained hollow-bearing tree as a recruitment tree to be able to develop into the hollow-bearing trees of the future. Trees meeting this definition are also high-quality sawlogs so the Forestry Corporation used to go to extremes to avoid their obligations to protect them, and were finally successful in having the requirement to protect recruitment trees removed in the 2018 Coastal Integrated Forestry Operations Approval. This up and coming cohort of future hollow bearing trees is rapidly declining due to natural mortality and logging. (see Protecting Habitat Trees)
If we are to minimise the hiatus in the availability of hollows for a plethora of native species we must act now to protect, as far as possible, all large old trees, along with sufficient recruitment habit trees to replace existing hollow-bearing trees as they die and to restore hollow-bearing trees throughout native forests.