Mt Gibson Sanctuary
Mt Gibson Sanctuary lies on a major transitional vegetation zone called the ‘mulga-eucalypt line’ that reflects a change in climatic conditions between the southwest and arid regions of Western Australia.
The topography and underlying geology are complex. The dominant landforms are greenstone ranges in the Northeast, and banded ironstone hills to the Northwest. Granites and gneisses of the Yilgarn Block underlie much of the property and outcrop as domes or breakaways at a number of localities. The ranges are separated by gently sloping pediments and flood plains upslope from salt lakes and clay pans. Sandplains occur extensively, particularly to the south. Drainage is disorganised and internal, and the extensive salt lake, Lake Moore, bounds Mt Gibson to the east.
The transitional location of Mt Gibson, combined with a highly variable topography, has led to an exceptionally high diversity of flora and fauna. The vegetation communities present on Mt Gibson are representative of the heavily cleared wheatbelt area of Western Australia and include magnificent eucalypt woodlands of Gimlet, Salmon Gum and York Gum. Mt Gibson is therefore an important repository of now rare wheatbelt flora, which is highlighted by the presence of 18 declared rare and priority flora. All of the 13 vegetation associations found on Mt Gibson are inadequately represented in current government conservation reserves, and five of these are not represented at all.