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A natural border is a border between states or their subdivisions which is concomitant with natural formations such as rivers or mountain ranges. The "doctrine of natural boundaries" developed in Western culture in the 18th century being based upon the "natural" ideas of Jean-Jacques Rousseau and developing concepts of nationalism . [ 1 ]
A landscape border is a mixture of political and natural borders. One example is the defensive forest created by China's Song dynasty in the eleventh century. [6] Such a border is political in the sense that it is human-demarcated, usually through a treaty. However, a landscape border is not demarcated by fences and walls but instead landscape ...
The realms delineate large areas of Earth's surface within which organisms have evolved in relative isolation over long periods of time, separated by geographic features, such as oceans, broad deserts, or high mountain ranges, that constitute natural barriers to migration. As such, biogeographic realm designations are used to indicate general ...
Natural sciences: the study of natural phenomena (including cosmological, geological, physical, chemical, and biological factors of the universe). Natural science can be divided into two main branches: physical science and life science (or biology). Social sciences and the humanities: the study of human behavior in its social and cultural ...
Physiographic Map from "Geography of Ohio," published in 1923. During the early 1900s, the study of regional-scale geomorphology was termed "physiography". Physiography later was considered to be a portmanteau of "physical" and "geography", and therefore synonymous with physical geography, and the concept became embroiled in controversy surrounding the appropriate concerns of that discipline.
Landscape patches have a boundary between them which can be defined or fuzzy. [15] The zone composed of the edges of adjacent ecosystems is the boundary. [6] Edge means the portion of an ecosystem near its perimeter, where influences of the adjacent patches can cause an environmental difference between the interior of the patch and its edge.
The boundary between Asia and Europe is unusual among continental boundaries because of its largely mountain-and-river-based characteristics north and east of the Black Sea. Asia and Europe are considered separate continents for historical reasons; the division between the two goes back to the early Greek geographers .
When edges divide any natural ecosystem and the area outside the boundary is a disturbed or unnatural system, the natural ecosystem can be seriously affected for some distance in from the edge. In 1971, Odum wrote, 'The tendency for increased variety and diversity at community junctions is known as the edge effect ...