Rocky Outcrops in Australia: Ecology, Conservation and Management

By Damian Michael and David B. Lindenmayer

Rocky outcrops are landscape features with disproportionately high biodiversity values relative to their size. They support specialised plants and animals, and a wide variety of endemic species. To Indigenous Australians, they are sacred places and provide valuable resources. Despite their ecological and cultural importance, many rocky outcrops and associated biota are threatened by agricultural and recreational activities, forestry and mining operations, invasive weeds, altered fire regimes and climate change.

Rocky Outcrops in Australia: Ecology, Conservation and Management contains chapters on why this habitat is important, the animals that live and depend on these formations, key threatening processes and how rocky outcrops can be managed to improve biodiversity conservation in agricultural landscapes, state forests and protected areas. This book will be an important reference for landholders, Landcare groups, naturalists interested in Australian wildlife and natural resource managers.

Recipient of the 2018 Whitley Certificate of Commendation for Landscape Zoology

• Language: English
• Publisher: CSIRO PUBLISHING
• Release date: Feb 1, 2018
• ISBN: 9781486307920

Book preview

ECOLOGY, CONSERVATION AND MANAGEMENT

DAMIAN MICHAEL AND DAVID LINDENMAYER

© Damian Michael and David Lindenmayer 2018

All rights reserved. Except under the conditions described in the Australian Copyright Act 1968 and subsequent amendments, no part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, duplicating or otherwise, without the prior permission of the copyright owner. Contact CSIRO Publishing for all permission requests.

The moral rights of the authors have been asserted.

National Library of Australia Cataloguing-in-Publication entry

Michael, Damian, author.

Rocky outcrops in Australia : ecology, conservation and management / written by Damian Michael and David B Lindenmayer.

9781486307906 (paperback)

9781486307913 (epdf)

9781486307920 (epub)

Includes bibliographical references and index.

Outcrops (Geology) – Australia.

Wildlife conservation – Australia.

Wildlife management – Australia.

Agriculture – Environmental aspects – Australia.

Land use, Rural – Australia – Management.

Lindenmayer, David, author.

Published by

CSIRO Publishing

Locked Bag 10

Clayton South VIC 3169

Australia

Telephone: [phone]

Email: [e-mail]

Website: www.publish.csiro.au

Front cover: (top) rocky outcrop (photo: Damian Michael); (bottom) Gidgee Skink on a rocky outcrop in eastern and south-western Australia (photo: Jules Farquhar)

Back cover: (left to right) Flat Rock Spider (photo: Jordan de Jong); Chattering Rock Frog (top) and Cave Frog (bottom) (photo: Brendan Schembri); Common Rock Rat (photo: Angus McNab)

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Edited by Anne Findlay, Princes Hill, Melbourne.

Cover design by Andrew Weatherill

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CSIRO Publishing publishes and distributes scientific, technical and health science books, magazines and journals from Australia to a worldwide audience and conducts these activities autonomously from the research activities of the Commonwealth Scientific and Industrial Research Organisation (CSIRO). The views expressed in this publication are those of the authors and do not necessarily represent those of, and should not be attributed to, the publisher or CSIRO. The copyright owners shall not be liable for technical or other errors or omissions contained herein. The reader/user accepts all risks and responsibility for losses, damages, costs and other consequences resulting directly or indirectly from using this information.

Original print edition:

The paper this book is printed on is in accordance with the rules of the Forest Stewardship Council®. The FSC® promotes environmentally responsible, socially beneficial and economically viable management of the world’s forests.

Contents

Preface

Acknowledgements

Chapter 1 Introduction and background

Why write a book on rocky outcrops?

What is a rocky outcrop?

Types of rocky outcrops

Protected rock formations

References

Chapter 2 Rocky outcrop values

Ecological values

Cultural heritage values

Economic values

References

Chapter 3 Australian rock-dwelling fauna

Reptiles

Frogs

Mammals

Birds

Invertebrates

References

Chapter 4 Threatening processes

Threats in different environments

Land clearing and loss of vegetation

Overgrazing by domestic livestock and feral herbivores

Introduced herbivorous invertebrates

Weed invasion

Introduced predators

Altered fire regimes

Physical threats to rocky environments

Climate change

References

Chapter 5 Managing rocky outcrops for biodiversity conservation

Managing rocky outcrops in agricultural landscapes

Management actions

Managing rocky outcrops in state forests and on Crown Land

Managing rocky outcrops in National Parks and other protected areas

Concluding comments

References

Appendix 1. Australian rock-dwelling fauna and their conservation status

Glossary

Index

Preface

Few places on Earth remain unaffected by human activities. Even remote wilderness areas show signs of human practices, and some of these impacts are clearly visible from space. As custodians of the planet, one of the greatest challenges in the 21st century is to reduce our footprint on the natural environment, while at the same time accommodating the needs of an increasing human population. Better integration of biodiversity conservation in human-modified landscapes is part of the solution. Rocky outcrops are environments where substantial improvements in their management can enhance biodiversity outcomes in landscapes that have been significantly altered by human activities. Rocky outcrops are exposures of bedrock that protrude above the Earth’s surface. Exposures of rock are found on all continents, in most climate zones and are prominent features of protected wilderness areas as well as landscapes that have been modified by humans. Rocky outcrops are considered sacred by Indigenous people, they provide valuable recreational opportunities and are places where people have the opportunity to connect with nature. They also have important ecological and socio-economic values, some of which present conflicting management and conservation challenges. Rocky outcrops in agricultural landscapes, on Crown Land and in state forests are often degraded and in need of urgent management. We trust that the information presented in this book promotes a broader appreciation of the natural history of rocky outcrops in Australia and helps provide guidance on their conservation and management.

Damian Michael and David Lindenmayer

June 2017

Acknowledgements

Damian Michael would like to thank Richard and Janet Michael for fostering his interest in the great outdoors, Tracy Michael for her support and Asha and Amber for their constant inspiration.

David Lindenmayer would like to thank his family for the support over the past 35 years of his research work.

Various organisations and agencies have supported this research, including the Australian Research Council, Ian Potter Foundation, Vincent Fairfax Family Foundation, Goulburn Broken Catchment Management Authority, North East Catchment Management Authority, Holbrook Landcare Network, Murray Local Land Services, Riverina Local Land Services and the National Environmental Science Programme.

This project has been assisted by the New South Wales Government through its Environmental Trust.

We thank our colleagues, David Blair, Ross Cunningham, Mason Crane, Daniel Florance, Christopher MacGregor, Lachlan McBurney, Thea O’Loughlin, Sachiko Okada and Jeff Wood. Clive Hilliker produced the illustrations and Claire Shepherd, Tabitha Boyer and Craig Michael assisted with manuscript preparation.

We thank the many landholders involved in our research over the years, particularly Sam Archer, Chris and Sue Cain, Frank and Judy Chalker, Frank Chambers, Rodger and Jenny Dietrich, Des Feuerhardt, Frank Forragan, Peter Herriot, Andrew and Leonie Mathie, Rodger and Elizabeth Paterson, Russel Paech, Frank Palmer, Gary and Sandra Schilg, Brett and Christine Schultz, Paul, Joan and Ian Trevethan and Peter Webb.

This book has benefited from the contributions made by many photographers. For this, we thank Zak Atkins, Sam Banks, Linda Broome, Rohan Clarke, Matt Clancy, Nick Clemann, Henry Cook, Matt Herring, Jules Farquhar, Jordan de Jong, Vince Kessner, Damian Lettoof, Jiri Lochman, Stewart Macdonald, Tiffany Mason, Angus McNab, Janice Mentiplay-Smith, Carol Probets, Julia Riley, Steve Sass, Brendan Schembri, Alison Skinner, Bruce Thomson, Jonathan Webb, Steve Wilson and Stephen Zozaya.

We thank John Manger from CSIRO Publishing, whose support for this book is sincerely appreciated.

1

Introduction and background

‘Australia has a history far more ancient than any written – to read this history is one of the objects of geology – records preserved in the great stone-book of nature.’

Reverend J. Milne Curran (1898)¹

Rocky outcrops are a characteristic and spectacular part of the Australian countryside. They have particular aesthetic appeal, and their solid appearance portrays an impression that they are hard and durable environments. While this is partly true – rocky outcrops have been exposed to the environment for millions of years – they are also extremely fragile ecosystems, and places that are easily disturbed by human activities. Many rocky outcrops, and the plants and animals associated with these environments, are at risk from key threatening processes such as altered fire regimes and overgrazing by livestock. Some of them are so degraded that they require immediate protection and ongoing management to improve their conservation value.

From an ecological perspective, managing rocky outcrops is important because they support high levels of biological diversity, provide refuge for specialised plants and animals and host a wide variety of endemic species. Rocky outcrops are significant, also from a cultural heritage perspective as many rock formations are sacred to Indigenous people. These landforms are also used for recreational and economic purposes, but such activities often lead to management conflicts and conservation challenges. Some rocky outcrops are afforded formal protection within national parks and nature conservation reserves. However, most found in Australia are outside the National Reserve System, and in many cases, rocky outcrops in agricultural regions, timber production forests or under mining leases have been heavily modified from their original condition.

Rocky outcrops are areas of bedrock that are exposed at the Earth’s surface. Millions of years of erosion have stripped away softer rock and soil (the regolith), leaving behind a core of much harder parent rock. Wind, water, sunlight and chemical reactions slowly eat away at the rock surface to produce rock formations with distinctive shapes and features. A common characteristic of rocky outcrops is their ‘island-like’ appearance protruding from flat or hilly landscapes. Rocky outcrops are found on all continents, most vegetation types and climate zones and vary considerably in size, shape and geology. They are well known for being hotspots for biological diversity, they support a wide variety of endemic plants and animals and are held sacred by Indigenous people around the world. (Photo by Damian Michael.)

Our aim in writing this book is to promote the ecological values of rocky outcrops in both natural and human-modified environments in Australia. We focus on why they are valuable and which animals depend on these environments for their survival. We also describe key threatening processes and how rocky outcrop management can be improved to enhance biodiversity conservation outcomes in different landscapes. By removing key threatening processes and improving the habitat quality of rocky outcrops, we strongly believe that these activities will contribute to reversing the decline of Australia’s biodiversity (Box 1.1). With the human population increasing and greater pressure being placed on the land to produce more food, we urgently need to improve biodiversity conservation in commodity production landscapes to prevent further species from declining or becoming extinct in the future (Box 1.2). We hope positive environmental outcomes can be achieved through the appropriate management of rocky outcrops in Australia.

Rocky outcrops are found in a wide variety of different types of landscapes from intensively cleared agricultural settings to wilderness areas and many other land uses. In landscapes that have been dramatically altered by human activities, such as farming and timber production regions of Australia, rocky outcrops are often damaged and degraded, many of which lack formal protection and require urgent restoration to improve their habitat and conservation values. Rocky outcrops located within conservation reserves are afforded better protection than those in commodity production landscapes, but many outcrops in conservation reserves are also under threat from processes such as air and water pollution and altered fire regimes. (Photos by Damian Michael.)

Box 1.1. Biodiversity loss in Australia

Since European settlement, Australia has lost an unprecedented number of species when compared to the rate of loss reported for other countries. According to the Australian Government Department of the Environment, 50 species of birds and mammals, four frogs and more than 60 plants have become extinct in Australia over the past 200 years.² More than 10% of Australia’s mammal fauna has been lost – ten times that of the USA (which is of an equivalent area). We have lost 28 species, the USA has lost just one. Furthermore, more than 300 species of native animals and over 1180 species of native plants are currently at risk of disappearing. There are several reasons why Australia’s plants and animals have declined, including habitat loss, predation by introduced predators (e.g. cats and foxes), introduced competitors (e.g. rabbits, goats, pigs and deer), altered fire regimes and diseases such as the amphibian chytrid fungus.³,⁴

By far the biggest threat to native wildlife is loss of habitat. ‘Habitat’ is the area, and all its resources, in which an animal or plant lives. Extensive clearing of temperate eucalypt woodlands for agriculture and livestock grazing has been a major cause of habitat loss over large areas of Western Australia and south-eastern Australia. In south-eastern Australia, over 85% of the temperate eucalypt woodlands have been cleared, with as little as 3% of some vegetation types, such as the endangered grassy box gum woodland, remaining.⁵ Many of the remaining patches of native vegetation occur on low-productivity land such as hilltops, ridges and steep slopes, places with little agricultural value or that were too difficult to clear. Many routine farming practices continue to result in incremental habitat loss and ongoing habitat degradation.

This book is written for readers with no specialist knowledge in ecology or geology, and so avoids technical language as much as possible. Where specialised terms are used, they are in bold and explained in the glossary at the back of this book.

Why write a book on rocky outcrops?

For more than 200 years scientists have been fascinated with the geology and geomorphology (the study of land forms and their processes) of rocky outcrops. Major land formations such as sandstone tablelands, karst landscapes and granite inselbergs have received considerable investigation, and many books on these subjects have been written.⁷ There has also been substantial interest in vegetation communities associated with rocky outcrops.⁸ Some of this work has focused on specific land formations such as granite inselbergs, or specific geological features such as cliff faces.⁹, ¹⁰ Far less attention has been paid to small rocky outcrops or land formations in commodity production landscapes. With new species being described from rocky environments across Australia on a regular basis, there is growing need to document the number of rock-dwelling species in these areas to address their threats and conservation status.¹¹, ¹²

Box 1.2. Land sharing versus land sparing

With the global human population rising at a rapid rate and increasing demand on the land to produce greater amounts of food, there is an urgent need to improve the integration of wildlife conservation in landscapes used for agriculture and fibre production. Conserving biodiversity on farms is important because plants and animals provide services that are essential for agriculture, such as nutrient recycling, pest control and pollination. However, in many places there is mounting pressure to clear more land and use existing farmland in more intensive ways. Given the intimate links between agriculture and biodiversity, new strategies are required to