Our world is becoming hotter. Australia is becoming drier. Other parts of the world are becoming wetter. Changes in eco-systems are normal but man’s activities are activating change at a rate more rapid than most species can adapt to. Biodiversity is becoming increasingly compromised.

The Southwest of WA is the only region in Australia to have been identified as a “Biodiversity Hotspot” by Conservation International. They have listed 24 Terrestrial Vertebrates as “threatened”, including three species of black cockatoo, Baudin’s, Carnaby’s and the Forest Red-tail.

Whilst these three species are still seen in the Darling Scarp area, they are actually becoming less common. If we do not protect them are likely to become extinct. The main threat to their survival is the loss of mature Marri and Jarrah trees which are their nesting and forage habitat.

Marri trees have to be over 300 years old for suitable nesting hollows to form. If you have a tree in your back yard or on your property with a large girth it could well play a crucial role in black cockatoos’ survival.

My Bedfordale property has eight majestic marri trees with girths between 2m and 4m that are 200 to 300 years old. They are regularly visited by cockatoos for forage but are not yet old enough for nesting hollows to have formed. To help these trees to stay healthy and eventually provide nesting sites I have fenced them off from livestock and inoculated them for dieback. Mini-nature reserves will be created around them with connecting wildlife corridors. Then I plan to register them as “Land for Wildlife”.

Contact Caralyn Lagrange (9498 1555) for information on keeping mature trees healthy, nature reserves and biodiversity corridors. Others contacts are your local CALM or Landcare officer.
Web information can be found on the NatureBase website:www.naturebase.net/content/view

Planting for Aesthetics, Fauna and Reduced Fire Risk

Reduced rainfall, higher temperatures and resultant dwindling water reserves are prompting many people to use indigenous plants in their gardens. These plants have adapted to Australia’s climate and fire regimes. Some are highly volatile – burning quickly and fiercely. Whilst they have survival mechanisms to regenerate after fire, people and property may not fare so well.
Other Australian natives, fortunately, are not only drought-tolerant and aesthetically pleasing, they are also fire retardant. This is due to a low oil content and a high water or salt content. To cater for local wildlife, I recommend planting fire-retardant species that are endemic to the area. Then, for more scope in landscaping, consider other fire-retardant Australian natives.
Fire-retardant groundcovers and shrubs of the Swan Coastal Plain and the Darling Scarp are Kennedia prostata (Running Postman), Hakea Laurina (Pincushion Hakea), Olearia sps (e.g.. Azure Daisy Bush), Rhagodia sps (e.g., Berry Saltbush) and native Wisteria and Pigface.

Larger shrubs and trees include Acacia Cyclops (Coastal Wattle), Acacia Saligna (Golden Wreath Wattle), Agonis Juniperina (Juniper Myrtle), Melaleuca Lanceolata (Rottnest Tea-Tree) and Pittosporum sps (e.g., Cheesewood).
Apart from local plant species, other native trees worth considering for their fire retardant characteristics are Lilly Pilly, Kurrajong, Silky Oak and Native Frangipani. Ground covers and shrubs include Dichondra, Native Violet and Pelargoniums.
Note: Most of these plants are available at specialist native plant nurseries. For more comprehensive lists of fire-retardant plants contact FESA, Boola Wongin Nursery or Zanthorrea Nursery. Web information is available from www.ilda.com.au or http://asgap.org.au/fire.html

Caralyn Lagrange B.A., B.Ed (Hons)
16 Nelson Street,
Bedfordale. 6112
(08) 9498 1555
www.bedfordale.com
agardenpath@bedfordale.com

All graphics and web design © Olivia Thorne 2004
All photographs © Caralyn Lagrange 2004