Juniperus virginiana


Juniperus virginiana, known as red cedar, eastern redcedar, Virginian juniper, eastern juniper, red juniper, pencil cedar, and aromatic cedar, is a species of juniper native to eastern North America from southeastern Canada to the Gulf of Mexico and east of the Great Plains. Further west it is replaced by the related Juniperus scopulorum and to the southwest by Juniperus ashei.

Description

Juniperus virginiana is a dense slow-growing coniferous evergreen tree that may never become more than a bush on poor soil, but is ordinarily from tall, with a short trunk in diameter. The oldest tree reported, from West Virginia, was 940 years old. The bark is reddish-brown, fibrous, and peels off in narrow strips. The leaves are of two types; sharp, spreading needle-like juvenile leaves long, and tightly adpressed scale-like adult leaves long; they are arranged in opposite decussate pairs or occasionally whorls of three. The juvenile leaves are found on young plants up to 3 years old, and as scattered shoots on adult trees, usually in shade. The seed cones are long, berry-like, dark purple-blue with a white wax cover giving an overall sky-blue color ; they contain one to three seeds, and are mature in 6–8 months from pollination. The juniper berry is an important winter food for many birds, which disperse the wingless seeds. The pollen cones are long and broad, shedding pollen in late winter or early spring. The trees are usually dioecious, with pollen and seed cones on separate trees.
There are two varieties, which intergrade where they meet:
Eastern juniper is a pioneer species, which means that it is one of the first trees to repopulate cleared, eroded, or otherwise damaged land. It is unusually long lived among pioneer species, with the potential to live over 900 years. It is commonly found in prairies or oak barrens, old pastures, or limestone hills, often along highways and near recent construction sites. It is an alternate host for cedar–apple rust, an economically significant fungal disease of apples, and some management strategies recommend the removal of J. virginiana near apple orchards
In many areas it is considered an invasive species, even if native. It is fire-intolerant, and was previously controlled by periodic wildfires. Low branches near the ground burn and provide a ladder that allows fire to engulf the whole tree. Grasses recover quickly from low severity fires that are characteristic of prairies that kept the trees at bay. With the urbanization of prairies, the fires have been stopped with roads, plowed fields, and other fire breaks, allowing J. virginiana and other trees to invade. Trees are destructive to grasslands if left unchecked, and are actively being eliminated by cutting and prescribed burning. The trees also burn very readily, and dense populations were blamed for the rapid spread of wildfires in drought stricken Oklahoma and Texas in 2005 and 2006.
Eastern juniper benefits from increased CO2 levels, unlike the grasses with which it competes. Many grasses are C4 plants that concentrate CO2 levels in their bundle sheaths to increase the efficiency of RuBisCO, the enzyme responsible for photosynthesis, while junipers are C3 plants that rely on the natural CO2 concentrations of the environment, although they are less efficient at fixing CO2 in general.
Damage done by J. virginiana includes outcompeting forage species in pastureland. The low branches and wide base occupy a significant portion of land area. The thick foliage blocks out most light, so few plants can live under the canopy. The needles that fall raise the pH of the soil, making it alkaline, which holds nutrients such as phosphorus, making it harder for plants to absorb them. However, studies have found that Juniperus virginiana forests that replace grasslands have a statistically insignificant decrease to a significant increase in levels of soil nitrogen. J. virginiana forests have higher overall nitrogen use efficiency, despite the common grassland species Andropogon gerardi having a far higher NUE during photosynthesis. The forests store much greater amounts of carbon in both biomass and soil, with most of the additional carbon stored aboveground. There is no significant difference in soil microbial activity.
Cedar waxwings are fond of the "berries" of these junipers. It takes about 12 minutes for their seeds to pass through the birds' guts, and seeds that have been consumed by this bird have levels of germination roughly three times higher than those of seeds the birds did not eat. Many other birds and many mammals also consume them.

Uses

The fine-grained, soft brittle pinkish- to brownish-red heartwood is fragrant, very light and very durable, even in contact with soil. Because of its rot resistance, the wood is used for fence posts. The aromatic wood is avoided by moths, so it is in demand as lining for clothes chests and closets, often referred to as cedar closets and cedar chests. If correctly prepared, it makes excellent English longbows, flatbows, and Native American sinew-backed bows. The wood is marketed as "eastern redcedar" or "aromatic cedar". The best portions of the heartwood are one of the few woods good for making pencils, but the supply had diminished sufficiently by the 1940s that it was largely replaced by incense-cedar.
Juniper oil is distilled from the wood, twigs and leaves. The essential oil contains cedrol which has toxic and possibly carcinogenic properties. The cones are used to flavor gin.
Native American tribes have historically used juniper wood poles to mark out agreed tribal hunting territories. French traders named Baton Rouge, Louisiana, from the reddish color of these poles. It is still used in ceremony by some Nations.
The Cahokia Woodhenge series of timber circles built by the precolumbian Mississippian culture in western Illinois was constructed using massive red cedar logs. One version of the circle, Woodhenge III, had 48 posts in the diameter circle and a 49th pole in the center.
Among many Native American cultures, the smoke of the burning cedar is used to drive away evil spirits prior to conducting a ceremony, such as a healing ceremony.
During the Dust Bowl drought of the 1930s, the Prairie States Forest Project encouraged farmers to plant shelterbelts made of Juniperus virginiana throughout the Great Plains. They thrive under adverse conditions – both drought tolerant and cold tolerant, they grow well in rocky, sandy, and clay substrates. Competition between trees is minimal, so they can be planted in tightly spaced rows, and the trees still grow to full height, creating a solid windbreak in a short time.
A number of cultivars have been selected for garden planting, including 'Canaertii' 'Corcorcor', 'Goldspire', and 'Kobold'. Some cultivars previously listed under this species, notably 'Skyrocket', are actually cultivars of J. scopulorum.
In the Missouri, Oklahoma and Arkansas Ozarks, eastern juniper is commonly used as a Christmas tree.

Allergen

The pollen is a known allergen, although not as potent as that of the related Juniperus ashei, which sheds pollen a month earlier. People allergic to one are usually allergic to both. J. virginiana sheds pollen as early as late winter and through early spring. Consequently, what begins as an allergy to Ashe juniper in the winter may extend into spring, since the pollination of the eastern juniper follows that of the Ashe juniper.
Contact with the leaves or wood can produce a mild skin rash in some individuals.