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Environment Forest Ecosystems Forest Industries Forest Management Forest Products Greenhouse Gases NAFI Submissions Policy and Politics Renewable Energy Sustainability |
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The Impact of Forestry on Ecosystems and Their Biodiversity.By Phil Townsend and Chris WagnerIntroductionThe Protection of Forest Ecosystems is governed by rules and regulations that differ in each state. These rules and regulations are designed to protect many unique species of Australian fauna and flora. As the system of renewable regrowth forest management on public land becomes more entrenched, new scientific evidence is demonstrating the limited impact of sustainable management practices on the biodiversity of Australia’s production forests. It appears that the mosaic of forest reserves and working forests may actually be helping to protect some endangered species. A number of Case Studies have reported that the protection of habitats in working forests has led to some populations fast approaching the numbers recorded in remnant native forests. A number of Conclusions have been drawn from this research. Case StudiesThe Pilliga Koala. A recent article on the Pilliga forest area, northern NSW (NSW State Forests, 2000) has found that the Koala population is thriving, way beyond expectations. The report found that “selective logging for White Cypress pine resulted in no changes to koala home-ranges or their occupancy of logged forests” (NSW State Forests, 2000). In fact the Pilliga Koalas are among the countries healthiest, genetically diverse and most vigorous Koala communities. Eden Koalas. In the NSW Southeast forests around Eden, koalas have always existed in low-density populations. A report published in the Institute of Foresters of Australia’s journal “Australian Forests” (Douch et al, 2001), found that forest practices in an area consisting of a combination of State, Private Forests and National Parks, had no adverse effects on the local Koala population. The report also found “the continued presence of Koalas in localities where they had previously been reported as extinct” (Douch et al, 2001). The survey technique used in the Eden study is based on recording and monitoring Koala grunts. This technique has most probably lead to an underestimation of koala numbers (Douch et al, 2001). The Square-Tailed Kite. NSW State Forests Annual Report, “Environmental Solutions”, contains a story on Square-tailed Kite populations in regrowth Black-Butt Forest areas suggesting that regenerated forests may be helping to stem the tide of fauna extinction (NSW State Forests, 2000). During the past seven years, over twenty nest sites have been tagged and protected to help retain the Square Tailed Kite population on the mid-north coast. As with the Eastern Cave Bat, large areas surrounding the Kite’s nest trees have been reserved from future timber harvesting operations, to promote the survival of such an important Australian species. The Feeding Habitats of Australian Bats. As with the nesting sites for threatened birds, trees that contain evidence of bat nests are excluded from harvesting operations. The exclusion of bat nest sites along with a 100-meter exclusion zone will help protect both the species and their habitat (NSW State Forests, 1995). State Forests of NSW have been studying the Eastern Cave Bat in the Bonalbo region around Casino (NSW State Forests, 2000). The study demonstrated limited foraging over the eucalypt regrowth forests, as the area is too cluttered with dense stands of young trees. However, an increasing level of activity was detected over roads and areas that had been thinned. The roads provided ready access between the roosts (nesting areas) and feeding grounds. It is possible that the bats were more active over areas of thinned forest due to reduced interference with their sonar. Bat Activity in Eden. A study conducted 22 years after intense logging operations around Eden (Law & Chidel, 2001), concluded similar findings to the Eastern Cave Bat study. Both studies reiterate the importance of retaining roost trees and the surrounding vegetation in designated exclusion zones. The Eden forests are part of an alternative coupe logging system where portions of the forest, approximately 15 ha in size, are harvested on a rotation system over an extended period of time. This system allows cross migration of fauna. The bat study complements the earlier work by Kavanagh (1985) which found that newly logged coupes have much smaller populations of native birds than the surrounding unlogged areas. However within four years of harvesting, regeneration of the forest vegetation resulted in 78% of native bird species having returned to the coupes (Kavanagh, 1985). The Glider and its Habitat. Another report found in the Australian Forestry Journal (McAlpine et al, 2001), reveals how scientists have been looking at the relationship between habitat loss in arboreal species like the yellow bellied, sugar, squirrel, feathertail and greater gliders in St Mary’s State Forest (near Maryborough in Queensland). The report is investigating options for landscape mapping to determine the impact habitat loss or forest fragmentation is having on the distribution and abundance of glider species. These outcomes are also determined by home range size, social organisation and diet. To complete these studies, fine detail is required on the forest structure. This detail will enable scientists to capture the variation in numbers of trees with hollows, across the landscape. The authors report that they should be able to overcome the difficulties associated with assessing eucalypt habitat complexity. They hope to do this through the development of digital remote sensoring techniques, which can capture within stand variations in forest age structure at a spatial scale of < 1ha (McAlpine et al, 2001) The Masked Owl of Northern NSW NSW State Forest researchers and two Ornithologists from Birds Australia are currently studying the Masked Owls, as they hunt along the edges of a southern pine plantation. Unlike Radiata Pine plantations that have a more dense crown cover, the area has a relatively sparse crown but a very dense underbrush, that is perfect for small ground-dwelling mammals to live. Perfect also for the Masked Owl to hunt in. The two owls, named Charlie and Albert are both occupying home ranges larger than 2,000 hectares and usually roost in the very large hollows found only in huge eucalypts, both living and dead, in adjacent Native forests. These trees and the surrounding area are always protected from harvesting. Protection of Forest EcosystemsNSW All forests and plantations, including both public and private, face very strict rules regarding the protection of native wildlife. In accordance with the Threatened Species Conservation Act (NSW State Forests, 1995) special protection zones are set up in ‘coupes’ containing any endangered fauna species, habitat and/or remnants thereof. A ‘coupe’ is a forest management unit that generally varies between 10 and 100 ha in size. The Threatened Species Conservation Act (NSW State Forests, 1995) has given forest owners and workers rigorous guide lines as to the requirements to be achieved around stream or river beds, and upon finding nest sites. Examples of habitat exclusion from harvesting, found in the Threatened Species Conservation Act: 1995. In high quality habitats a minimum of twelve hollow-bearing, or recruitment trees must be retained in every two hectares of net logging area. The Threatened Species Conservation Act (16:1995) states the different types of quality habitats directly relate to the amount of hollow-bearing and recruitment trees, and dependant on the dominant tree species (17:1995) Depending on the size of the stream or water flow an exclusion zone of no less that 10 meters, and as much as 50 meters, either side of the bank must be protected (20:1995) Exclusion zones of at least 40 meters must be created around all areas of wetlands, of a size larger than 70 by 70 meters, or 0.5h (21:1995). Nest and roost sites must be protected, depending on the fauna species, for example, a Powerful Owl nest requires a 50-meter exclusion zone, while a Square-tailed Kite nest requires a 100 meters radius (22:1995). ConclusionMeasures such as these have elevated Australia to becoming a world leader in sustainably managing its natural resource. Legislation like the Threatened Species Conservation Act (1995) and the Regional Forest Agreements are providing the framework for forest owners and workers to help protect the valuable resources at their disposal. References Douch, A. et al (2001) A playback survey of the Koala, Phascolarctos cinereus, and a review of its distribution in the Eden Region of southeastern New South Wales. Australian Forestry, Volume 64, Number 4. The Institute of Foresters of Australia: ACT Kavanagh, R, P. (1985) Bird populations of a logged and unlogged forest mosaic at Eden, New South Wales. Birds of Eucalypt Forests and Woodlands: Ecology, Conservation, Management. Ornithologists Union: NSW Law, B, S. & Chidel, M. (2001) Bat activity 22 years after first-round intensive logging of alternate coupes near Eden, New South Wales. Australian Forestry, Volume 64, Number 4. The Institute of Foresters of Australia: ACT McAlpine, C, A. et al (2001) Mapping glider habitat in dry eucalypt forests for Motreal Process indicator 1.1e: fragmentation of forests. Australian Forestry, Volume 64, Number 4. The Institute of Foresters of Australia: ACT NSW State Forests (1995) Terms of Licence Under the Threatened Species Conservation Act. NSW State Forests: NSW NSW State Forests (2000) Environmental Solutions. NSW State Forests: NSW |
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