indigenous trees of Ellenbrook

I thought I'd take a minute to list the many indigenous trees we have in our local bushland. Trees are an important part of the environment. They provide food, shelter, roosting and nesting sites for animals. They recycle nutrients in the soil and air. They act as windbreaks and provide protection for hundreds of smaller plants. The healthiest and most inviting suburbs around Perth seem to be, to me, the ones with the most indigenous trees.

So, here's our list of trees for Ellenbrook:

Eucalypts - we have four; Jarrah (Eucalyptus marginata), Marri (Corymbia calophylla), Coastal Blackbutt aka Pricklybark (Eucalyptus todtiana) and Flooded Gum (Eucalyptus rudis). Jarrah and Marri can grow to around 45m high, and live for hundreds of years. (Who said there are no big trees on the Swan Coastal Plain?) Pricklybark prefers dry hilltops, while Flooded Gum can be found growing on the edges of wetlands. This is a Pricklybark.


Paperbarks - we have two that reach a respectable tree size; Stout Paperbark aka Moonah (Melaleuca preissiana) and Swamp Paperbark (Melaleuca rhaphiophylla). Average height is around 10m, but there are some enormous ones in Bush Forever Sites around the place. The largest ones have a girth measured in metres, and are likely to be hundreds of years old. Both species have small white flowers. This is a small Moonah in flower in December (top photo).
The big Moonah (photo under) shows how big they can grow - I estimate that one to be about 15m tall, and about a metre thick at eye level.


Banksia - we have five species that occur naturally; Candlestick Banksia (Banksia attenuata), Firewood Banksia (Banksia menziesii), Holly-leafed Banksia (Banksia ilicifolia), Swamp Banksia (Banksia attenuata) and Bull Banksia (Banksia grandis). The first two of these prefer dry conditions, and the others are usually found in or near wetlands. These five trees have overlapping flowering times throughout the year, so there's always at least one species in flower to keep the Honey Possums well-fed. Here's the Holly-leafed Banksia in its natural habitat, as "teenagers" - the adult trees are larger, more open and branched.


Sheoaks - there are two tree species; Sheoak (Allocasuarina fraseriana) and Swamp Sheoak (Casuarina obesa). Sheoaks have fine whispy branches, and when in flower these appear to be tinged red. The tall whispy tree in the middle of the photo is Swamp Sheoak.

And lastly, we have our famous WA Christmas Tree (Nuytsia floribunda), the world's biggest mistletoe. The distinctive orange flowers appear in December. The soft fleshy leaves feel cool to touch on a hot summer's day. Here's a photo:

Fourteen species altogether! Please comment if I've left any out...

the future of our drinking water

Yesterday (22 July), there was a public forum in Ellenbrook to discuss the future of the "Gnangara Mound", an underground body of water north of the Swan River. More than half of Perth's scheme water is pumped out of this aquifer, and this is where our bore water comes from as well. The aquifer is recharged by rainwater and stormwater soaking down into the ground. Perth's rainfall has been diminishing over the last couple of decades, and there are more people and industries using water, so water levels in the Gnangara Mound are decreasing.

This will affect how much water we will have for drinking and other uses in our homes. It will affect what kinds of fruit and vegetables we might be able to buy locally. It will affect industries, horticulture, maintenance of parks and playing fields, and the appearance of our suburb.

More demand for water, less water available = problems.

What does this mean for bushland? Many areas of banksia woodland are suffering because tree roots cannot reach water in summer, so trees are dying off. Some wetlands are suffering also because they no longer have enough water; paperbark wetlands are drying up when they should be under half a metre of water in winter. Ultimately, it means that our bushland will change to drier vegetation. This will in turn affect the many animals that depend on plants such as Banksia and Melaleuca, including Carnaby's Black-Cockatoo and Honey Possums.

I and a couple of fellow members of the Ellenbrook Bushland Group attended the public forum to share our ideas about the management of this store of water.

You can have your say too. You will need to download and read the Gnangara Sustainability Strategy. Then you can fill out the accompanying public submission form, and email or post it to the address given on the form. The closing date for submissions is 5pm Monday 31 August 2009. All the public comments will be collected and analysed, and the results will be available later this year.

If you live in Ellenbrook, or anywhere in Perth for that matter, and are concerned about the future of our drinking water, you should take part in this public comment process. Maybe you have a brilliant idea that will help solve the Gnangara Mound problems?

the rather confused Banksia

Such fantastic weather this weekend inspired me to go for a long-ish bushwalk. I went out with friends to look for one of Ellenbrook's best kept secrets, maybe not a secret for much longer....

The HYBRID Banksia!!! Check this out!

Why is this a hybrid? Well, it has the thin serrated-edged leaves, and yellow flower colour, of the Candlestick Banksia (Banksia attenuata). But see how the flowers are opening from the bottom of the inflorescence? The shape of the inflorescence is from the Firewood Banksia (Banksia menziesii). (Banksia attenuata has tall skinny inflorescences, like candlesticks.)

For comparison, here are photos of the two potential parents. On the left, Banksia menziesii (pink "acorn-shaped" flower, wide crimped-edge leaves), and Banksia attenuata (yellow cylindrical flower, skinny sawtooth-edged leaves), below.



Perhaps we can blame the European Honey Bee for this genetic mischief!



So, we think it's a Banksia attenuata x menziesii. Cross-pollination probably doesn't happen that often because the trees flower at different times of the year, with only a small overlap in flowering times.

It's been 18 months since we found the tree in the top photo, and today we just had to go back into the bush and see if we could find it again. I was hoping to record the location properly for future research.

Unfortunately, we ran out of time, and didn't find the tree. Better luck next time!

European House Borer Forum - 9th July

Just a reminder - there will be a Forum about the effects of the European House Borer in Ellenbrook on 9th July.

Venue: Ellenbrook Community Resource Centre; above the library in Main Street
Time: 7 pm
Date: Thursday 9th July

The European House Borer is a small beetle. Its larvae (caterpillars) eat untreated pine wood, and have been found in structural timber in some houses in Ellenbrook, as well as nearby pine plantations. It was accidentally brought into WA in untreated wood, and now it has become a pest in several Perth suburbs.

The City of Swan and the Department of Agriculture and Food are presenting this Forum so Ellenbrook residents can find out what is being done about this exotic pest, and how they can help.