We simply cannot afford to remain so ignorant about the design and operation of ecological systems. A more elaborate and comprehensive synthetic theory involving infertile soils, unpredictable precipitation and primary productivity, Triodia , and termites was recently proposed by S.R. Morton and C.D. James. Another extremely important and interesting mechanism for maintenance of habitat heterogeneity and lizard diversity involves disturbance and a complex fire succesion cycle. 1 Fires are a predictable event in arid Australia and generate a spatial mosaic of patches of habitat at various stages of postfire succesion. A more or less regular agent of disturbance, bushfires are usually started by lightning and rage completely out of control for weeks on end across many square kilometers of desert.
Fires vary considerably in intensity and extensiveness.
Eucalyptus trees are fire-resistant and usually survive a hot but brief ground fire carried by the exceedingly flammable Triodia grass tussocks. Moreover, fires frequently reticulate, missing an occasional isolated grass tussock or even large tracts embedded in or immediately adjacent to burns. Effects on lizards and lizard microhabitats are drastic, yet exceedingly heterogeneous in space. Many or even most individual lizards may survive such burns, although survivorship is probably drastically reduced for some time afterwards. Other lizard species require large spinifex tussocks for microhabitats, nearly vanishing over extensive open areas following a burn.