In Europe, much of the wildlife interest and the important landscapes, together with the cultural heritage, depend on the countryside as a whole, rather than just protected areas. This is partly because humans have interacted with the natural environment for thousands of years, and because many of the domestic livestock are derivatives of previous wild European species. So, although European farm animals have been exported around the world, causing a mixture of benefit and chaos, in Europe these farming systems have continuity with previous more natural systems _ most of which no longer exist. Europe's natural and cultural heritage is thus enriched by the wide variety of regional farming systems which work in harmony with local environmental conditions. However, many of these farming systems are currently under threat by replacement with systems which are less related to local conditions _ but which rely on large inputs of energy and chemicals, and generally reduce wildlife in the areas.