| OCR Text |
Show 4o BASIS OF AMERICAN HISTORY [ 1500 extreme northwest. \ In the northern belt ( the trees are the same or similar across the continent, and but few species appear, the most typical feeing the poplars and the black and white spruces, which near their northern limit are stunted and of no economic importance, but farther south yield valuable timber. 1 On the east the forest originally formed an unbroken sheet along the entire Atlantic coast as far south as central Florida, and along the Gulf shore into Texas, the general western boundary of the forest reaching or even crossing the Mississippi. The Pacific belt ceases to connect with the Atlantic at about the sixtieth parallel, near the eastern slopes of the Rocky Mountains; there the prairies interfere and form along the western edge of the Atlantic forest a broad area which is but slightly wooded. A short distance south of the forty- ninth parallel the wooded region of the Pacific forks, the coast division being densely covered with very valuable timber, while the Rocky Mountains in many parts are also well supplied with trees. x Between these two Pacific groups, and even more in the wide extent of country between the Rocky Mountains and the western edge of the prairies, trees are practically wanting. The main factor in determining this distribution is the rainfall; in dry regions trees are few or absent, although in limited regions they may be raised by water conducted from a river or other source of supply through artificial channels and distributed over the land as required. |
