Conserving Biodiversity in Brigalow Regrowth - School of ...

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Key habitat features What are the most important features for fauna in a brigalow woodland stand? 18 High-quality Brigalow habitat complex habitat structure For most fauna, a tree canopy is not enough. In a patch of brigalow woodland, more complex habitat structure means more species will find a home. For example, small birds such as finches and fairy-wrens need dense vegetation, preferably spiny shrubs, for protection from predators. Dense understorey also helps to keep aggressive noisy miners out. Reducing grazing pressure within areas of brigalow woodland can preserve the important shrub layer and allow it to regenerate. Even areas of young regrowth brigalow can act as shrubby habitat for small birds. WILL GOULDING MICHIALA BOWEN a messy ground layer A messy ground layer is a good ground layer. Terrestrial reptiles and small mammals need fallen timber and leaf litter for shelter, and this environment also favours the invertebrates on which they feed. Melon holes hold water and create important microhabitats for frogs and reptiles which prefer damp areas. MICHIALA BOWEN Mistletoes Mistletoes are an often misunderstood component of Australian woodlands. There are many native species of these semi-parasitic plants in Australia and they provide important food (fruit and nectar), shelter and nesting habitat for many types of animals. Their leaf litter also benefits ecosystems by returning nutrients to the soil and enriching the ground layer. Grey mistletoes (Amyema quandang) are particularly abundant in narrow linear strips of remnant brigalow. Although many people worry that heavy mistletoe infestation will cause tree death, the science is less clear. We do know that their benefits generally out-weigh any negative effects. They are unlikely to harm healthy host trees and they are very important for maintaining the abundance and diversity of woodland birds that live in, or travel along, these remnant strips. Hollows and logs Hollows, cracks and crevices in trees and fallen logs are homes and havens for animals and plants in the brigalow. They provide places for animals to hide, breed, feed and bask. We often see lizards soaking up the sun’s rays on a log, but many animals prefer to stay out of harm’s way in hollows and crevices: sleeping, laying eggs, giving birth or caring for young. Cracks and crevices in old and dead trees harbour native species that will be rendered homeless if needlessly removed. Logs on the ground help trap moisture and reduce erosion as well as acting as a refuge for plants and animals. Bryophytes (collective term for mosses, hornworts and liverworts) are often conspicuous on logs; the highest bryophyte abundance and diversity occur on old logs. Numerous species of invertebrate eat bryophytes, lay their eggs on them or shelter in them and this gives rise to a chain of higher order organisms that utilise this abundance of invertebrates. For example, many ants use older, decaying logs and this attracts their predators such as native legless and burrowing lizards.
CONSERVING BIODIVERSITY IN BRIGALOW LANDSCAPES Problem species ALEX McTAVISH Noisy miner The noisy miner (or mickey bird) is a native, but problematic species. Despite the name, it is not related to the introduced common (or Indian) myna, but to the Australian honeyeaters. Unlike most of our birds, it has benefited from the changes that humans have wrought in the landscape, and is more common now than prior to European settlement. Unfortunately, it is very aggressive towards other birds. Living in large groups, noisy miners will chase and ‘mob’ intruders to their territory. In almost all cases, smaller birds are chased away. Larger birds are attacked too, but are often a bit more resilient. This means that a patch of woodland which is home to a colony of noisy miners is generally only habitat for large, common species like apostlebirds, magpies, butcherbirds and large parrots, while all the small woodland birds – many of which are declining – are absent. In fact, noisy miners pose one of the greatest challenges for conservation of our woodland birds in eastern Australia. To control noisy miners, we need to look at what it is that makes a landscape suitable for them in the first place. Noisy miners prefer woodlands that have an open tree structure, with little understorey, and which is grazed. If we can increase the density of trees in sparse brigalow vegetation, the number of noisy miners will be reduced and this means that small birds will return. Some of the key things that can be done to help woodland birds to avoid aggression from noisy miners include: 1) encourage and protect shrubby understorey; 2) manage grazing pressure so that it does not degrade native vegetation; and 3) value dense stands of trees and regrowth, which noisy miners do not like. Around the house, planting dense shrubs in the garden and limiting the amount of nectar-producing shrubs and trees can help too. Most of our honeyeaters (like the spinycheeked, striped and singing honeyeaters of the brigalow) actually mostly eat insects, so they won’t mind! CAMERON GRAHAM Foxes and cats Introduced predators like the European red fox and the feral cat are not just a nuisance for farmers but also have a devastating effect on wildlife. A wide range of native animals are vulnerable to predation by these exotic species, including small mammals like dunnarts and planigales, birds that nest and feed near the ground, and many different reptile species. Landscapes dominated by cropping and with many roads and small fragments of brigalow provide optimal conditions for cats and foxes to hunt and breed. We recorded the greatest frequency of feral predator activity near linear woodlands and roadsides, and the least in the interior of large brigalow patches. Therefore, focusing pest control along roads and linear strips may increase success in controlling these pests, and using regrowth to buffer and enlarge brigalow patches could help reduce their impact on wildlife. ANDREW SMITH Buffel and green panic Non-native pasture grasses like buffel and green panic may be good for grazing animals, but when they grow in brigalow woodland they out-compete the native understorey plants, which are an important part of wildlife habitat. They also increase the risk of bush-fires that kill the brigalow trees. Our research in the region between Goondiwindi and Emerald has shown that these grasses will thrive in linear strips of brigalow that have a more open tree canopy as a result of droughts and other disturbances causing tree deaths. These grasses are particularly abundant in the northern Brigalow Belt as they prefer areas with a high mean maximum temperature and high mean annual rainfall. With predictions for a hotter regional climate across the Brigalow Belt, these non-native grasses may replace the native understorey plants that are important for wildlife habitat. 19
Page 2 and 3: PARTNERS CONTRIBUTORS Associate Pro
Page 4 and 5: Foreword Times change. In 1960 when
Page 6 and 7: Brigalow Landscapes The Brigalow Be
Page 8 and 9: Between the Wars After WWI, develop
Page 10 and 11: threats to brigalow Although the br
Page 12 and 13: Scales of Habitat Management Managi
Page 14 and 15: How much vegetation? The main reaso
Page 16 and 17: Managing dense Brigalow regrowth: T
Page 20 and 21: Iconic species and their habitat WI
Page 22 and 23: limbs and under loose bark on old t
Page 24 and 25: LIST OF VERTEBRATE SPECIES recorded
Page 26 and 27: QUICK REFERENCE GUIDE 1. How much v

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