Juniperus virginiana

Juniperus virginiana, also known as red cedar, eastern red cedar, Virginian juniper, eastern juniper, red juniper, and other, local names, 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 (Rocky Mountain juniper) and to the southwest by Juniperus ashei (Ashe juniper).

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 5-20 m or 16-66 ft tall, with a short trunk 30-100 cm or 12-39 inches in diameter (rarely to 27 m or 89 ft in height, and 170 cm or 67 inches in diameter). 940 years was the oldest tree ever recorded, and it came from West Virginia. The bark is thick and fibrous and has a reddish brown color. The leaves are of two types; sharp, spreading needle-like juvenile leaves

5-10 mm (3/16–3/8 in) long, and tightly adpressed scale-like adult leaves 2-4 mm (1/16–3/16 in) 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 3-7 mm (1/8–1/4 in) long, berry-like, dark purple-blue with a white wax cover giving an overall sky-blue color (though the wax often rubs off); they contain one to three (rarely up to four) seeds, and are mature in 6-8 months from pollination. Many birds use the juniper berry as a winter food, and they disperse the wingless seed. The pollen cones are 2-3 mm (1/16–1/8 in) long and 1.5 mm (1/16 in) broad, shedding pollen in late winter or early spring. The trees are usually dioecious, with pollen and seed cones on separate trees, yet some are monoecious.

There are two varieties, which intergrade where they meet:

Ecology

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 has the potential to live for over 900 years, which is an unusually long life span among pioneer species. 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

It is considered an invasive species in many places, even though it may be native. It is fire-intolerant, and was previously controlled by periodic wildfires. The tree’s lower branches provide a ladder for fire to reach the entire tree from the ground. Low-severity fires are a common feature of prairies that kept trees away. Grasses recover quickly. 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.

The Eastern juniper enjoys higher CO ₂ levels than the grasses it faces. While many grasses are C4 plants, which concentrate CO ₂ in their bundle sheaths in order to increase RuBisCO’s efficiency, photosynthesis enzyme, RuBisCO, junipers, are C3 plants, which rely on (and could benefit from) the natural CO ₂ levels of the environment. However, they are less efficient at fixing CO ₂.

J. Virginiana can cause damage to pastureland forage species. A significant amount of land is occupied by the low branches and large base. 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 (NUE), despite the common grassland species Andropogon gerardi having a far higher NUE during photosynthesis (PNUE). 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 12 minutes for the seeds to reach the birds’ stomachs. The seeds of birds that have eaten these junipers have a germination rate three times greater than seeds they did not consume. They are also eaten by many other birds, including bluebirds and turkeys as well as mammals.