Agricultural And Industrial Transformation Period

Forest clearing for agriculture was the primary cause of deforestation in eastern North America (Whitney 1994). Only 10%-30% of the forest remained in southern New England by the mid-1800s; coastal forests had been cleared much earlier (Niering et al. 1970). As settlers moved into the Ohio Valley, they established farms until, by 1900, most (85%) of the land had been cleared (Sutherland 1997). Similar events played out in the Lake States (Pyne et al. 1996) and the Southeast (Martin and Boyce 1993). From 1860 to 1910, the rate of conversion to agriculture accelerated such that more forests (190 million acres) were converted during this period than in all previous time since European arrival in North America (M. Williams 1989, Powell et al. 1993). Since the 1850s, forest clearing and drainage of wetlands for agriculture have caused the loss of 70%-98% of bottomland forests in the United States (Sharitz and Mitsch 1993).

During this agricultural revolution in North America, fire was used by settlers to clear forests, maintain farm and pasture, and improve the woods for grazing, as the Indians had done but on a much grander scale. Forests were further disturbed by cattle and hogs, who grazed freely everywhere Europeans settled (Cronon 1983, M. Williams 1989, Whitney 1994). Grazing on open range was practiced in many regions (e.g., Ozark highlands) as late as the 1950s and 1960s. Livestock grazing affected forest regeneration, often eliminating it in the understory of woodlands and savannas.

Locally throughout the range of the oak, the production of charcoal for the iron industry affected the surrounding forests. Forest harvesting for charcoal peaked in the late eighteenth century in the Piedmont and Coastal Plain regions (Orwig and Abrams 1994) and later in the nineteenth century in the Midwest and Northeast (Sutherland 1997). Forests were harvested on short rotations (e.g., 20-30 years) and fires fueled by logging slash burned with greater intensity (Cronon 1983, M. Williams 1989, Whitney 1994). These practices created coppice forests dominated by oaks (Clatterbuck 1991, Orwig and Abrams 1994).

Industrial logging transformed the forests of eastern North America during the period from 1850 to 1930. Forest harvesting had previously been a local activity to supply the timber and fuelwood needs of nearby villages and specialty products sought by foreign sovereigns (e.g., masts for British sailing ships). Small populations and primitive transportation systems limited the need and the ability, respectively, to lumber extensively. Timber was transported by log drives down rivers that had connections to ocean ports. Not until railroads were built into the more remote forested regions were many forests linked to population centers. This set the stage for the wholesale logging and "destruction" of eastern North America forests documented in Ontario (Howe and White 1913), the South (Martin and Boyce 1993), the Lake States and Northeast (Cronon 1983, M. Williams 1989), the Ozarks (Cunningham and Hauser 1989), and the central hardwood region (Hicks 1998). Beginning in 1850, the annual production of forest products increased markedly; in 1910 an estimated 13 billion cubic feet of timber were harvested (Powell et al. 1993). Repeated and often catastrophic fires burned the cutover forests. The forests had never before experienced disturbances of such extent or severity. Far from being destroyed, the forests renewed themselves, although they changed in character. This logging and fire history favored the oaks, which rose like the phoenix out of the ashes to assume widespread dominance throughout eastern North America.

Much of the eastern forests have developed on agricultural land abandoned during the late 1700s in the Northeast, Mid-Atlantic, Piedmont, and Coastal Plain, and later in the Midwest, Lake States, and other interior regions. The regrowth of forest on agricultural lands accelerated during the Great Depression. Often, these forests were dominated by pine and oak (Orwig and Abrams 1994). Oak seedlings and grubs sprouted in pastures and, in the absence of mowing or grazing, grew to maturity. Elsewhere, stands dominated by pine provided ideal conditions for oaks to establish and grow in the understory, setting the stage for oak dominance after the pine was harvested. As agricultural land was abandoned throughout the Midwest, Lake States, and Southeast, the amount of forest land increased.

In some places, forest cover has increased to levels approaching that seen by the first European settlers. Current forest acreage in eastern North America equals about two-thirds of the forest area estimated to have existed in the 1600s. In the unglaciated plateau in Ohio, forest cover has increased from 15% to 65% over the past 100 years (Sutherland 1997), and Vermont has gone from being 65% cropland in 1850 to 77% forested today (Powell et al. 1993). Since 1907, the extent of forest land in the United States has stabilized at 730-760 million acres. The change in proportions is due largely to a cessation of forest clearing for agriculture (Powell et al. 1993). Deforestation in the lower Mississippi River bottomlands continues today, however (Sharitz and Mitsch 1993).

Europeans brought to the New World insects and diseases that have affected forest composition and succession over large areas. One of the most notable examples was the introduction of the chestnut blight (Endothia parasitica [Murrill] P. J. Anderson and H. W. Anderson), which eliminated chestnut as a major overstory species in eastern North America by the early 1900s. Oak dominance increased after the loss of chestnut in the Appalachian and mid-Atlantic regions (Hinkle et al. 1993, Abrams and McCay 1996, Hicks 1998). Chestnut oak, red oak, and scarlet oak replaced chestnut. The introduction of exotic species and the spread of invasive species will continue to modify natural forest succession and alter native forest character (see Chapters 6 and 7).

Forest product manufacturing in the United States declined from 1910 until after World War II, when a boom in the housing market sparked an increase in harvesting (Powell et al. 1993). Since then, production has increased (see Figure 4.1), resulting in historic levels of harvesting, but annual growth of hardwoods in the East still exceeds timber removals (e.g., by 80% in 1991). In the eastern United States, most (94%) of the 380 million acres of forest land is timberland; this proportion has been relatively constant since the early 1950s (Powell et al. 1993). About half of the eastern forest land is classified as oak-pine (32.2 mill. a.), oak-hickory (129.7 mill. a.), or oak-gum-cypress (29.2 mill. a.) forest type, and the largest areas of highly productive (> 120 cu. ft. per acre per year) forest lands occur in the oak-hickory and loblolly-shortleaf pine types. Most of the timberlands in the East are owned by private

0 -(---1---■---1->——r—-t 1 ' " ——

Î8G0 Î820 1840 ISË» 1880 1900 1920 1940 J9MS 1980

Figure 4.1. Domestic production of forest products from 1800 to 1985 in the United States. (Adapted from Powell et al. 1993.)

0 -(---1---■---1->——r—-t 1 ' " ——

Î8G0 Î820 1840 ISË» 1880 1900 1920 1940 J9MS 1980


Figure 4.1. Domestic production of forest products from 1800 to 1985 in the United States. (Adapted from Powell et al. 1993.)

industry (16%) and nonindustrial private individuals (70%), and they are primarily responsible for the hardwood harvest (e.g., 90% of the hardwood production in 1991).

Unfortunately, written management plans have been used by only an estimated 5% of private forest land owners, who control 39% of the private forest lands (Birch 1996). More than half of all private forest lands have no management plans. Although it is difficult to quantify the amount of timber harvested by regeneration method, common harvesting techniques on unmanaged private land include selective cutting or high grading and diameter limit cutting. These rogue harvesting practices create small gaps in the overstory canopy, which usually do not favor oak development, especially on the more productive sites. Harvesting by these methods often results in understocked stands of reduced quality and value.

Was this article helpful?

0 0

Post a comment