Small offshore islands greatly extend both countries jurisdictions. Key geographical features of the region are its relative isolation in an oceanic hemisphere, Gondwanan ecosystems and unique flora and fauna, low human population densities, and significant climatic features such as the ENSO phenomenon, the very arid interior of Australia, and tropical cyclones. The ecosystems of the region are extremely varied, owing to the range of climates arising from the large latitudinal range, the continentality of Australia, and the mountainous, maritime nature of New Zealand. New Zealand has generally ample rainfall and mainly low-temperature limited ecosystems. Many parts of the region have been subject to significant human influences, particularly from the use of fire, widespread agriculture, vegetation clearance, deforestation, and other land-use change and from the introduction of exotic plants and animals particularly rabbits and foxes in Australia and rabbits, deer, and Australian possums in New Zealand.
Environmental pollution is relatively low, in line with the low human population.
Half of Australia s population lives in just four coastal cities. Both countries have strong relationships with Pacific island countries, in some cases extending to specific constitutional responsibilities, and they are home to sizable populations of Pacific Islanders. Large populations outside the region are dependent on the region s agricultural exports. The two countries have open market economies, are members of the OECD, and in general have good access to the capital, technological, and human resources needed to adapt to the impacts of climate change. Primary industries are a cornerstone of the region s economy.