There are five principle forest regions in North America that comprise the coniferous forest. The forests are equally spread geographically between east and west. Because of the forest's great size, and because of differing climate and soils, North America is favored by a rich variety of these "evergreens". It is interesting to note that this forest supports four times as many tree species as Europe does.
The Pacific Coniferous Forest Region:
This forest region runs along a thin strip of land for three thousand miles, from Kodiak Island in Alaska to the Santa Cruz Mountains near San Francisco is the Pacific Forest. This forest has the most prodigious growth of conifers unequalled anywhere on earth. A combination of temperature, rainfall, and topography creates conditions favorable for growing the largest living organisms - the inland sequoias and the coast redwoods .
The Olympic rainforest of Washington supports dense stands of western hemlock , western red cedar, Sitka spruce , and Pacific silver and grand firs. Douglas fir is concentrated in Washington and Oregon. Alaska's predominate species is the western hemlock and Sitka spruce.
The Rocky Mountain Coniferous Forest Region:
This Rocky Mountain forest region is more sparsely covered with trees. The most important trees here are ponderosa pine , western white pine, Douglas fir , lodgepole pine , and Engelmann's spruce. The use of fire in this region made it possible for big stands of lodgepole pine to take hold.
In the sub-alpine zone of the mountains spruce and fir predominate, and they are succeeded near the timber line by larch, whitebark pine, limber pine and bristlecone pine. The bristlecone pine has been discovered to be the oldest living thing.
The Northern Coniferous Forest Region: This Northern forest region spreads across four thousand miles, from Alaska to Newfoundland and down the higher peaks of the Appalachian mountains. In the north woods, white and black spruce grow. The soil throughout the Northern Forest is generally poor.
The most visible tree type in the region are conifers. The most prevalent conifers are balsam fir , eastern hemlock , northern white cedar, and eastern white pine . This northern region supplied much of the lumber used in the first 250 years of settlement in the United States.
The Central Coniferous Forest Region:
The Central forest region touches 30 states from Cape Cod to the Rio Grande and back up to Canada. This forest is mostly deciduous which means that is green in the summer and bare in the winter. Although the main component is hardwood, there are several important softwoods. Eastern white pine and Virginia pine are common throughout the forest.
The Southern Coniferous Forest Region:
The Southern forest occupies the coastal plains of the Atlantic from Virginia through the Gulf States and into Texas and Missouri. It is generally a forest created from abandoned old fields - many of which grew cotton.
Four important pines - the shortleaf , longleaf , slash and loblolly - make up most of the southern coniferous forest. To a lesser extent, baldcypress clings to swampy land and eastern redcedar grows on poorer lands.
Top 100 American Tree Species - Conifers
Major hardwood species listing from your Forestry About.com Guide.
Index of Forest Maps, Facts and Figures
Land and forest cover maps from the Natural Resources Conservation Service.
A Gymnosperm Database
Great site edited by Christopher J. Earle