Research

What is the Pinaceae panacea?

Cones and consequences: the false dichotomy of conifers vs broad-leaves has critical implications for research and modelling, was a viewpoint article from the new Phytologist which Sydney member Chloe (Sydney) found interesting. https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.70136

Webinar

Mark from Tathra brought to our attention this recent webinar hosted by the Victorian Forest Alliance, presented by David Lindenmayer: Disturbance-stimulated flammability – links between logging, previous fire and wildfire risk

Australia is the most fire-prone continent on earth. However, in more recent years there has been a significant increase in the frequency, severity, extent and homogeneity of wildfires in this country. Climate change is a key driver of these changes. But so too is the way forests are managed.

In this webinar, David outlines the evidence for changes in fire regimes associated with forest management, including logging, thinning and even (in some cases) past prescribed burning.

Book review

The Geology and Flora of the Sydney Basin – A Photographic journey

John Martyn (2024)

Published by STEP Inc, Turramurra NSW

Reviewer- Peter Juniper

No wonder John Martyn’s book “The Geology and Flora of the Sydney Basin – A Photographic journey”, all 551 pages of it, weighs so much. It is an impressive encapsulation of the region. Holding this book feels like you’ve got the whole area’s geology and flora distilled into one concentrated hand-held mass.

The Sydney Basin is part of the global biodiversity hotspot called the Forests of Eastern Australia and extends from the upper Hunter River south to Lithgow, Bungonia, and Ulladulla on the coast. This huge area includes a temperature stable coast to inland mountains that can snow, rolling gentle hills to deeply dissected plateaus and infertile sandstone to rich volcanic basalts. These landscapes are formed on recent post-glacial sand dunes to rock nearly 300 million years old (think of early conifers, ginko trees, lungfish and early land animals).

This book begins with an overview of the Sydney Basin, telling the story of its geological development over millions of years. The point is then made that the geology of the basin is responsible for its varied landform, soil form and microclimate – hence its floral diversity. The bulk of this book journeys over the Sydney Basin to show you all the kinds of geological features and vegetation types to be found and is organized according to the successive geological layers of the Sydney Basin; from the Early Permian Epoch (some 300 million years ago) to the current post-glacial period. It is interesting to note that embedded within the Permian strata are rocks deposited by melting glaciers! This tells you how much things have changed for this land over time – back then Australia was much closer to the south pole and colder.

Each of the main rock layers that form the Sydney Basin is introduced with its tectonic context, ancient climate and the dominant plants of the time. This is followed by excellent diagrams and photographs of the finer layers with a description of their characteristic current vegetation types and plant species – particularly the trees. Further details on landscape features, rocks, vegetation communities and notable plant species are also provided with numerous photographs and explanatory notes. A small final chapter shows you the flora grows on the Sydney Basin’s abundant rocks, including the characteristic Sydney Red Gums, ferns of waterfalls and the hanging gardens of sandstone cliffs. Wisely, for a book such as this, a glossary has been included, and of course an impressively detailed index and list of references. An appendix with detailed descriptions of rock samples also exists.

John Martyn’s book is a detailed definitive piece. However, the story of the Sydney Basin could be more easily understood if the introduction included the formation of the Sydney Basin summarized in perhaps two pages with a minimum of technical words. This would need to be accompanied by illustrations of the basin’s changing landform over time (and its broader tectonic setting). The subsequent detail in the book then has an easily understood schema to slot into. Some tectonic context could, for example, illustrate how and when sediment reached the Sydney Basin from Antarctica – which is an amazing thing to consider!

For someone such as I who grew up on Sydney’s shorelines, exploring its sandstone, heath, woodlands and cool secluded gully rainforests, this book is a treasure. It is a book you can delve into to find something new and interesting every time. For example, I now know why the Nepean River meanders, albeit through steep country – it was originally meandering over a low plain before the land was lifted millions of years ago and the river continued to maintain its path, etching it down through the sandstone. Should you want to carry this book outside you could easily find many of the scenes that have been photographed and read about them on the spot. Alternatively, sites can be investigated prior to a visit for an introduction to their ecology and geological origins, and any notable plant species. Hence this book is of value not only to the rock hound, but the bushwalker and the ecologist.

John Martyn’s book “The Geology and Flora of the Sydney Basin – A Photographic journey”, with its breadth and detail will remain a definitive text for many decades to come. What’s more, it will preserve an impression of this beautiful region far into the future, despite the changes that will come with time.