Taking all the genera and species together, there is a far greater variety in the eastern than in the western forests. A considerable number of genera, perhaps a third of the total, grow within both regions, but the species having continental range are few. They are the following: Larch (Larix laricina), white spruce (Picea canadensis), dwarf juniper (Juniperus communis), black willow (Salix nigra), almond leaf willow (Salix amygdaloides), long leaf willow (Salix fluviatilis), aspen (Populus tremuloides), balm of Gilead (Populus balsamifera), and hackberry (Celtis occidentalis).
ORIGINAL FOREST REGIONS OF THE UNITED STATES.
| Area | Area | |
|---|---|---|
| Thousand acres | Per cent. | |
Northern forest | 158,938 | 8.4 |
| Hardwood forest | 328,183 | 17.3 |
| Southern forest | 249,669 | 13.1 |
| Rocky Mountains forest | 155,014 | 8.1 |
| Pacific forest | 121,356 | 6.4 |
| Treeless area | 887,787 | 46.7 |
| ———— | —— | |
| Total land area | 1,900,947 | 100.0 |
THE DISTRIBUTION AND COMPOSITION OF NORTH AMERICAN FORESTS.
- References:*
- Sargent, Forest Trees, Intro., pp. 3-10.
- Bruncken, pp. 5-16.
- Roth, First Book, pp. 209-212.
- Shaler, I, pp. 489-498.
- Fernow, For. Inves., pp. 45-51.
- Fernow, Economics, pp. 331-368.
* For general bibliography, see [p. 4.]
Chapter V.
THE FOREST ORGANISM.
The forest is much more than an assemblage of different trees, it is an organism; that is, the trees that compose it have a vital relation to each other. It may almost be said to have a life of its own, since it has a soil and a climate, largely of its own making.