Saturday, 12 October 2013

The Lost Rocks of Sydney...

  

 Some of the enduring features of Sydney are the wonderful sandstone outcrops which are dotted around the city and suburbs. In fact, this metropolis is built on top of a giant swathe of sandstone around 50 metres thick. The eroded matter was brought here around 200 million years ago, in the form of sandy deposits, by an ancient river. Many of Sydney’s iconic old colonial buildings are made from this attractive yellow-brown material.

 Immense bulky formations of sculptural sandstone sit heavily at the end of cul-de-sacs, hover broodingly over backyard gardens or majestically frame our beaches. They were mostly too hard to shift when the bulldozers came through, so they were often skirted around and left in a lumpen "too hard basket". Today they are somber and silent reminders of a lost landscape, a forgotten time, an ancient past. 



 These rocky edifices also harbour some of our last remnant suburban biodiversity; ferns, trees and bushes that tenaciously cling to the surviving islands of undeveloped land. The outcrops don’t have a lot of naturally occurring plant-life on them but the species that do (or should) exist, are critical to the fauna of these nutrient poor and thermally stressed environments

  Almost from day one, post European settlement, these native plant refuges have been under siege from invaders. Tenacious weeds were unthinkingly brought here from overseas such as English Ivy, Morning Glory, Asparagus fern, Mother of Millions, Lantana, Honeysuckle and Agapanthus. These, and other opportunistic plants such as Fishbone fern are now blanketing the rock faces and crowding out the indigenous specimens.  Chances are, most of Sydney’s signature rocky outcrops are all but invisible, literally buried beneath a festoon of introduced species.

  One example, among a multitude, is the towering rocky cliff featured below. It was blanketed by a thick green curtain of weeds, but the promise of something special hiding unobtrusively beneath was still evident.
The guys from Rock Face Renaissance decided to move in for a exercise in rejuvenation. Check out what happened...

This was the subject rock face before the "renewal" 

The weeds were gradually peeled back to reveal some hidden natives


..



...an Eriostemen...
...and a glorious grass tree emerge "gasping" from beneath the Fishbone ferns
The giant curtain of ivy is also slowly drawn away and underneath is...
Indigenous but barely surviving, Coral fern 
...and an ancient Fork-fern

(Skeleton Fork-fern (Psilotum nudum) is one of the most primitive and simple plants around and its descendants can be traced back 410 million years. They are truly living relics. Amazingly you can still see them on the rock face adjoining the Opera House and on Cockatoo Island..most passers-by wouldn’t give them a first glance, let alone a second one).
An unusual looking Skink also enjoys the new found light 

Martyn Robinson from the Australian Museum advises that this is an “interesting one” and is  known as a gully skink, (Saproscincus Spectabilis/Galli)  http://en.wikipedia.org/wiki/Saproscincus_galli

Meanwhile, this juvenile southern leaf tailed gecko shows off its amazing camouflage
There are many other similar sandstone formations on the Northern Beaches (see examples below) and across Sydney that could also urgently do with some TLC.  Email me at cowfish5@bigpond.com  if you have some examples.


A rocky, but weedy, headland at Queenscliff
A rocky but  weedy "Welcome to Warringah"
A rocky, but weedy streetscape in Manly Vale


 Check out this blog next time to see how our subject rocky outcrop has been amazingly resuscitated and rejuvenated after decades of neglect.