WEST KIMBERLEY PLACE REPORT - Department of Sustainability ...

species such as the northern quoll (Dasyurus hallucatus), the golden bandicoot
(Isoodon auratus), the scaly-tailed possum (Wyulda squamicaudata) and the golden–
backed tree–rat (Mesembriomys macrurus) are of particular importance due to their
decline on the mainland caused by an array of human–induced threatening processes.
The northern Kimberley coast and islands, the Kimberley Plateau and the west
Kimberley Devonian reefs have outstanding heritage value to the nation under
criterion (a) for plant, mammal, reptile, frog and invertebrate species richness
and endemism; and also as refugia in protecting against human-induced
environmental changes.
Vine thickets: Evolution in the litter
Vine thickets (rainforests) make a considerable contribution to the floristic diversity
of the Kimberley region. Four hundred and fifty-three (453) plant species have been
recorded from 99 patches (out of an estimated 1,500) of rainforest, representing about
25per cent of the Kimberley flora, in a total area of rainforest of less than 8,000 ha
(Kenneally et al. 1991, Kenneally and McKenzie 1991). Northern Territory
rainforests possess a higher generic richness and higher species numbers (604) found
in a total of 1,245 sites (Liddle et al. 1994). The rainforests of the Iron and McIlwraith
Ranges of Cape York while possessing a greater richness in plant species than the
Kimberley (1,156 species in Iron Range National Park alone), are more comparable to
the wet, structurally complex rainforests of the Wet Tropics. The dry, structurally
simpler vine thickets growing inland of Townsville show far greater similarity to the
Kimberley's rainforests. Thickets inland of Townsville, such as at Toomba, Undara,
and Chillagoe form similar small isolated patches that possess low plant species
richness (Thurgate 1996). However surveys of the area (Fensham 1995) found the
largest patches associated with basalt flows, such as those found at the Toomba Lava
Flow (160 species in a 512 kilometre 2 patch) possessed greater species richness than
the larger patches in the Kimberley, where the maximum recorded in any patch was
119 species (Kevin Kenneally pers. comm., 19 November 2009).
Most plant species in the Kimberley rainforests also occur in rainforests of the
Northern Territory and/or Cape York, indicating likely bird and bat fruit dispersal
(Kenneally et al. 1991; Price 2006). Liddle et al. (1994) identified that 78 per cent
(404 species) of Northern Territory rainforest species are shared with Queensland and
51 per cent (266) shared with the Kimberley. These proportions highlight the relative
floristic continuity of the northern Australian rainforest flora. Only one species
Hibiscus peralbus (Malvaceae) is considered endemic to the Kimberley. The Northern
Territory rainforests include 36 species that are considered locally endemic (Liddle et
al. 1994) and the inland Queensland vine thickets shelter a few endemic plant species
but largely share species known from the wetter, more coastal rainforest areas of
Queensland (Thurgate 1996).
The likely young age of the Kimberley's rainforests may not have provided sufficient
time to enable these communities to play an evolutionary refugial role to allow the
development of a specialised endemic vertebrate fauna (Barlow and Hyland 1988;
Covacevich and McDonald 1993; Kendrick and Rolfe 1991). Friend et al. (1991)
noted that only a few mammals, such as northern long-eared bat (Nyctophilus
daedalus) and the mosaic-tailed rat (Melomys burtoni) show regular dependency on
Kimberley rainforest patches. Most of the 29 mammals recorded from Kimberley
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