Blue Gum Walk

The dominant tree in this area is the Sydney Blue Gum (Eucalyptus saligna). With its smooth slate-grey bark and rough, brown ‘sock’, it forms part of an extremely rare ecological community known as Blue Gum Diatreme Forest. As little as 14 hectares of this community remains in existence and may now be solely confined to the Hornsby local government area. It occurs here because of the deep clay soils, produced by the weathering of the volcanic rock of the Hornsby diatreme which is located under your feet.

Timber has been harvested in this valley from the 1820s right up until the 1960s, and the trees we see today are comparatively young natural regrowth.

Notice the wriggly markings on the smooth trunks? These are made by Australia’s largest native land slug, the Red-triangle Slug (Triboniophorus graeffei) as it grazes upon algae.

On the eastern side of the trail above Old Mans Creek, you may notice a dense grove of trees. They are commonly known as Sassafras (Doryphora sassafras) due to the pleasant scent of the leaves. This species is now very rare in the region and Hornsby Shire Council is currently undertaking restoration works in the area to assist with their growth and spread.

The large hill to the west of the trail is called Joes Mountain, though how it received its name is unclear. In 1967 the late Dr Joyce Vickery, a botanist with the Royal Botanic Gardens, donated over 100 acres (40.5 ha) of land around the hill for conservation, most of which forms part of Berowra Valley National Park.

At the foot of the hill on the western side of the trail is a large stand of Turpentines (Syncarpia glomulifera). As with the Sydney Blue Gums, these stringy-barked trees were also valued for their timber. Here they mark an end to the diatreme-derived soils.

A large and remarkable Sydney Red Gum (Angophora costata) is positioned on the eastern edge of the fire trail at this location. With its smooth pink or orange bark and distinctive contorted limbs, old trees such as these contain hollows which provide vital nesting sites for many native birds, mammals and insects. Can you see any currently being used? This tree is reported to have been hit by lightning.

The Fishponds are a series of waterholes situated on a bend in Berowra Creek. Sit quietly for a while and keep your eye out for Eastern long-necked turtle (Chelodina longicollis), Australian short-necked turtles (Emydura sp.) and Eastern Water Dragons (Intellagama lesueurii lesueurii) as they bask on rocks or fallen logs. You may even catch a glimpse of a huge invasive Common Carp (Cyprinus carpio) as it swims lazily by.

This crossing at Waitara Creek boasts lovely cascades and ‘washtub’ pools sculpted from the creek bed. Known as Hawkesbury Sandstone, this rock type underlies most of the Sydney region. Feel the sand and quartz grains laid down around 200 million years ago, when Sydney was a vast floodplain and dinosaurs roamed the earth.

This thin, high ridge separates Berowra Creek to the west from Waitara Creek to the east. Lovely views of Berowra Valley extend to the north and Joes Mountain sits to the east. The vegetation on this ridge is called Peppermint-Angophora Forest. One of the main canopy species here is the Sydney Peppermint Gum (Eucalyptus piperita). You may recognise this tree by its grey, rough bark, with ribbons of bark hanging off the upper branches. The leaves have a ‘peppermint’ smell, which is the reason for its common name.

You may notice a change in the vegetation, as the trail moves from a dry exposed northerly slope to a more shady and moist southerly aspect.See if you can mark the place where the Sydney Blue Gums start appearing again.

Notice the row of English Oak trees along the Ginger Meggs Loop. These once lined the approach to an old dwelling that was situated on the flat clearing above.