Endangered banksia ecosystem in Perth faces destruction with no adequate offset, expert says | Endangered habitats

Property developers in Perth plan to raze the endangered Banksia ecosystem used by threatened black cockatoo species, and conservation experts have warned the damage will not be mitigated by proposed offsets.

Developers want to replant the Banksia ecosystem into a different type of protected woodland; The proposal is doomed to failure, a leading botanist says.

The forest area, which will be bulldozed for three public housing projects, is home to species including threatened Baudin and Carnaby black cockatoos.

Restoration specialist and national expert on the ecosystem known as the Banksia woodlands of the Swan coastal plain. Kingsley Dixon said he had “deep concerns” about the proposal to offset clearing by trying to create Banksia woodlands from scratch within another type of woodland in protected reserves around Perth.

Dixon said the proposals put forward by environmental consultancy Emerge Associates for the three developments effectively “forced one system into another” and that it was unlikely that a Banksia ecosystem would be created to suit the diversity of areas cleared.

“For example, would it be appropriate to topple and raze rare grasslands in New South Wales? [to compensate] “Do you put them in the Blue Mountains?” he said. “Or do we take the loss of the Kosciuszko mountain species and put something in the plains near Sydney?”

Dixon said he had been working with restoration teams in Banksia woodland across Perth for 40 years and “we still haven’t created a hectare of the ecosystem from scratch”. He said they had tried to restore existing parts of the Banksia woodland but were unable to restore it to its original state.

“This is not simple gardening,” he said.

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Balancing biodiversity means compensating environmental damage caused by development by providing equal or greater environmental benefits elsewhere. But offsetting has been beset by problems, including that promised offsets are sometimes never delivered or fail to adequately compensate for environmental loss.

Like other capital cities in the country, Perth faces a housing shortage; The average house price in Western Australia’s capital city exceeds $1 million.

Some new developments are increasing the pressure on already threatened ecosystems such as Banksia forests.

Species in the woodland include herbaceous plants, flowering woody shrubs and native sedges. A canopy layer contains banksias and eucalypts.

The habitat supports the threatened Baudin and Carnaby black cockatoos, as well as insect communities and animals such as the honey opossum.

It is the collective mix of species that creates a “broader ecological balance” for a resilient Banksia woodland ecological community “with a unique community of species not represented elsewhere,” Dixon said.

One of the three housing projects, two in Perth’s south and one in the north, was approved by the federal environment ministry last year, while the other two are under evaluation.

Many of the offset options put forward by Emerge Associates would involve trying to create Banksia woodland from scratch within tuart woodlands on public reserves. Tuart is a critically endangered ecosystem in its own right if the right conditions are provided.

Dixon said Tuart woodlands had the wrong soil and canopy type to support a true Banksia woodland. He said the two ecosystems had some species in common, and that it was possible for a simple Banksia woodland species to exist in a tuart woodland, but not the same type of complex Banksia ecosystem as the one cleared.

It said this meant the proposed offsets were unlikely to deliver a similar environmental benefit and there would be a net loss of Banksia woodland as it approached the critically endangered category.

Brendan Sydes, national biodiversity policy officer at the Australian Conservation Foundation, said the proposals underlined concerns that offsetting was becoming a tool to facilitate development at the expense of sensitive species and ecosystems, rather than a last resort.

“These examples show an over-reliance on trade-offs and an optimistic assumption about the ability to regenerate ecosystems, when in many cases the answer should be ‘no, don’t destroy habitat,’” Sydes said.

“We’ve reached a point where there are very few things left where conservation should be the priority.”

Detailed rules on offsets are under development following the adoption of changes to Australia’s national environmental laws last year.

“It is critical that it places a constraint on when supports can be used, and that new rules and offset funds do not actually act as an accelerator of habitat destruction by facilitating inappropriate use of biodiversity offsets,” Sydes said.

A spokesman for the Federal Environment Agency said it was “working closely with environmental consultancy to ensure that offset is achievable and compatible with Banksia” on the housing development it has approved. [threatened ecological] community known to coexist with Tuart woodlands.”

They said the project was approved with “strict” conditions for ensuring and monitoring offsets.

They were unable to comment on two developments that are still under evaluation. They said the federal offset policy does not prevent offsets on public lands.

A spokesperson for Emerge Associates said a public consultation process was conducted for each development, including proposed offsets, and public feedback was reflected in the assessment documents.

They stated that some developments are still being evaluated by the ministry.