Blue Gum High Forest is an open moist forest, located in the northern suburbs of Sydney, along ridge lines between Crows Nest and Hornsby. The name comes from one of the dominant tree species within the forest, the Sydney Blue Gum (Eucalyptus saligna). The forest only grows on shale soils, with a maximum of only 5% of the original area still in existence today. The remnant areas are mainly in Hornsby, Willoughby, Ku-ring-gai, Ryde and Parramatta.

Plant species

I’m not going to include an exhaustive list of plant species as that would be boring, but I’ll briefly mention some of the main ones. As mentioned, the Sydney Blue Gum is one tree here in this plant community. Other tall trees also include Blackbutt (Eucalyptus pilularis) and Sydney Red Gum (Angophora costata).

Shrubs and small trees include blueberry ash (Eleaocarpus reticulatus), forest oak (Allocasuarina torulosa), narrow-leaved geebung (Persoonia linearis) and mutton wood (Rapanea variabilis).

Vines, nets and grasses include the maidenhair fern (Adiantum aethiopicum), flax lily (Dianella cearulea), common ground fern (Calochlaena dubia) and wonga wonga vine (Pandorea pandorana).

Other facts about blue gum high forest

Blue gum high forest belongs in areas where rainfall is over 1100 millimetres per year. The shale soils (coming from the Wianamatta Shale underneath it needs to be deep. The tallest trees can reach 30 metres high. Some of the animals that live within this ecosystem include the glossy black cockatoo and the grey-haired flying fox-both of which are endangered species.

The ecological community (an Australian term used by Australian governments to describe different types of vegetation types like blueberry gum high forest and other forest/heathland/vegetation community types) is listed as critically endangered by the national and NSW state governments.

Why? At the most, only 5% of blue gum high forest still exists intact with the structural integrity the it has always had. All remaining areas of this forest are threatened due to threats from clearing and invasion by non-native plants. Fragmentation of the remaining areas of this forest reduces the genetic variation within each pocket of the forest, meaning that it may not be as robust and adaptable to the wider climatic and environmental conditions that it sits it. Pollution from external sources like roads and the stormwater runoff from them when it rains can be a problem-this runoff can contain excess nutrients and pesticides, which aren’t good for anything (pesticides kill things, even the plants/animal you want alive rather than dead and excess nutrients are not needed as many, if not most Australian species can deal with relatively poor nutrition in soils). Waste dumping is an issue in certain areas too. Certain pathogens, including Myrtle rust (many Australian species, including eucalyptus trees are in the Myrtaceae family and are really prone to this disease) and phytophthora are often a problem.

How to reduce the threats to blue gum high forest?

The obvious ones for those living next to, or near, the forest should ensure weeds in their garden are minimised if not removed completely. If possible, plant species in the garden too (but you can have other plants too, provided you keep them under control). If really keen, you can join bush care groups to help maintain these areas through weeding, planting, rubbish removal, etc. Of course, local governments can help by ensuring the prevention of land clearing, etc to protect these areas.

Why should blue gum high forest be protected?

The only reason that should matter in answer to this question is because each different ‘ecological community’ (or however you want to describe it) is different and unique, we should keep what we have left and treasure it for itself. I went to Dalrymple Bay Nature Reserve today. The sounds of the birds, the leaves rustling and wildlife rusting the undergrowth are just wonderful to hear. The smells are just so amazing too-the smell of eucalyptus trees in the summer after rain is the best smell going! I have always been a lover of nature, so maybe that alters my perspective a little. That leads to the question of other reasons to ‘care’.

Going anywhere in nature has been proven to be good for our mental, as well as physical, health-something I can’t argue with at all. While this will take a lot of research, there are many plants that may be able to help with medicines to cure diseases. The more biodiversity we keep, the more plants we can look at to help.

All in all, I love Australian wildlife and plants and I love sharing it. Nature benefits us all in so many ways and blue gum high forest is important for its own sake, along with having wider for importance. All I can say is take care of any natural areas you have near you and respect it.