States of Austria arable terrain. The other five states, in contrast, are located in the Alps and thus are comparatively unsuitable for agriculture. Their terrain is also relatively unfavourable to heavy industry and long-distance trade. Accordingly, the population of what now is the Republic of Austria has been concentrated in the former four states since prehistoric times. Austria's most densely populated state is the city-state of Vienna, the heart of what is Austria's only metropolitan area. Lower Austria ranks only fourth with regard to population density even though it contains Vienna's suburbs; this is due to large areas of land being predominantly agricultural.
Environment of the United States of the country's total land area. Protected parks and forestland constitute most of this. As of March 2004, approximately 16% of public land under Bureau of Land Management administration was being leased for commercial oil and natural gas drilling; public land is also leased for mining and cattle ranching. As with many other countries there are a number of environmental issues in the United States. Topical issues include the Arctic Refuge drilling controversy and the Bush Administration's stance on climate change. Climate change, species conservation, invasive species, mining, pesticides, and waste are just some of the environmental issues in the