Virginia Pine

People in the Appalachian Mountains and Piedmont provinces are likely to know Virginia pine as scrub pine. As an initial tree species following fire and in old-field ecological succession, the seemingly ubiquitous dead twigs find use as kindling for a Boy Scout's "two-match" fire. The species, however, is not limited to the mountains and their foothills. It occurs throughout most of the Atlantic Coastal Plain, from New Jersey to Georgia, and in vast pure stands in the Cumberland Plateau of Tennessee. While the species is generally succeeded by shortleaf and loblolly pines following its pioneer appearance on deforested sites, in the 1950s a remnant virgin forest in northern Alabama included Virginia pines in mixture with shortleaf pines.27 Indicator plants delineate site potential for this species. In the northern part of Virginia, two such vegetative covers occur. Better sites—Site Index (SI) 50 to 70—are characterized by flowering dogwood and clubmoss, while bear oak (one of the scrub oaks) and reindeer moss (less demanding of the nutrients of a site than the true mosses) indicate average and poorer land productivity—SI 30 to 50.28

Mycorrhizae fungi, the microscopic growths on pine tree roots, especially affect the vigor of Virginia pine. How favorable or detrimental the effect is depends on soil moisture. As root systems are small when moisture is low, the proportion of rootlets infected with the favorable fungi Cenococcum granifome and Thelephora terrestris increases. Their abundance also is greatest in dry summers, increasing as much as 10-fold with decreasing available moisture. Apparently the mycorrhizae lack competitive ability in moist soils.

Photoperiod and the kind of light available also affect the growth rate of Virginia pine. In greenhouse trials, stem elongation and the number of leaves on seedlings increased by extending day length from 8 to 16 hours. Hence, longitudinal range restriction may be related to day length.

As for all southern yellow pines, seed development for Virginia pine requires almost two years from the time of flower formation. The time varies slightly, depending on longitudinal position. In Mississippi, pollen is disseminated in mid-March; in the colder clime of North Carolina, ripening of the flower-like strobili occurs in late April.

Flowers develop almost every year, enabling frequent seed production so that hardly a season passes in which an abandoned field or burned-over forest may not be naturally regenerated. Seedfall begins in late October and continues until the following spring, though the number of seeds released from the cones drops off appreciably by late December. The trees in open stands are most prolific. Although seeds are disseminated each autumn, heavy seed crops occur with regularity every three years. Natural regeneration also comes from sprouts arising from dormant buds near the bases of charred trees.

Meadow mice nibble at Virginia pine seedlings and saplings in dense stands. This is especially so adjacent to cutover lands where grasses and forbs provide a habitat that encourages the increase of rodent populations. Small beads of resin form on the exposed wood where the mice gnaw on the bark, seldom more than 8 inches from the ground. Later, a white resinous coating appears and, still later, a black resinous rim forms around the injured area. The mice feed on trees in winter when sap is the most readily available moist substitute for creek water, which is frozen and unavailable at that time.

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