The Australian arid zone is a large complex area. In order to maintain its biodiversity, it is essential that landscape-wide and long-term analyses form the backdrop to the development of management strategies. From the current knowledge of the biodiversity and ecology of the arid zone, it is evident that there has been a loss of about 50% of the mammalian fauna and a reduction in the distribution and abundance of bird and reptile species since European settlement. But our knowledge of arid ecology is limited, with the majority of data representing a single snapshot in time, from sites that are a mere pinprick on this landscape, which constitutes 70% of the area of Australia. Scale, both spatial and temporal, is a critical issue underlying our understanding of this landscape. In this paper, three key elements affecting the biodiversity and ecology of this landscape are discussed: climate, fire and European settlement. Rainfall is known to be highly variable in space, time and intensity yet it is routinely described by mean values. Understanding long term trends is of greater value for sustainable management. CUSUM analysis is a valuable technique for demonstrating rainfall trends and illustrating when trends change from a sequence of drying years to an increasing trend. It also provides an indication of water availability in the landscape. Most of our ecological knowledge has been collected within the last 50 years, a period of increasing water in the landscape when conditions have been good more often than they have been bad. Superimposed on this is the episodic nature of major ecological changes, with naturally occurring floods and fires shaping the landform and distribution of vegetation communities, in addition to the more subtle successional changes. Spatial heterogeneity is another critical element, with fertile patches ranging from centimetres to hundreds of kilometres in size scattered across an infertile landscape. There is no one recipe for the sustainable management of the arid landscape. Flexible, adaptable management strategies, based on a long-term understanding and analysis, are required. It will also be critical to effectively engage land managers through the development of environmental stewardship programmes and rewards to encourage management for biodiversity alongside production. Integral to these management strategies is the careful use of fire, a tool lost by the removal of Aboriginal management. Some ecological parameters have been defined for the centre and west of the arid zone, where most research has been carried out. While some of these are relevant in the east, it differs ecologically and in terms of the severity of the impact of European settlement. There is an urgent need for further ecological research in the east of the arid zone.