User:Ecologywowza/sandbox

Description
Privet (Ligustrum sinense Lour.) is a perennial shrub or tree that is shade-tolerant, evergreen, and a member of the Olive Family. It can grow up to 9 m tall with grey bark and branching reddish stems. Privet’s leaves are opposite, oblong, leathery, and pointed. Its fruit grows in spiral clusters and range from purple to black in color. Although considered a weed, it is often used as an ornamental plant in gardens due to its flowers. The flowers are small, unpleasantly pungent, and borne in panicles. They have four curled-back petals and two high stamens with yellow or red anthers, between which is the low pistil; the petals and stamens fall off after the flower is fertilized, leaving the pistil in the calyx tube. Flowering starts after 330 growing degree days.

Privet is most commonly found wherever there is disturbed soil, soil that is physically perturbed from its natural state through fire or mechanical machinery, such as along fencerows, old fields, ditches, and forest margins Privet grows particularly well in riparian forests, which are found throughout the southeastern United States. Although tolerant of varying soil and light conditions, including a tolerance for shady, privet survives best in mesic soil with abundant sunlight. Privet is an invasive shrub in the Southeastern United States. It is estimated that Chinese Privet alone currently occupies over one million hectares of land across 12 states

History in the U.S.
All nine species of privet, currently in the southeast U.S., are invasive. The first species of privet was introduced into the United States in the 1700s as an ornamental plant used as a hedge or foliage for gardens. Glossy Privet arrived in the U.S. in 1794, Chinese Privet in 1825, Japanese Privet in 1845, California Privet in 1847, and Amur Privet in 1860. Most privet escaped cultivation in the early 1900s, becoming naturalized during the 1950s-1970s. Currently Privet is a top weed in Alabama and Georgia and considered a sever threat in North Carolina and Florida.

Uses and Cultivation
In addition to being cultivated to create ornamental hedges and foliage, Privet is also widely used in horticulture and flower arrangements. Privet is used to create living screens and privacy barriers, while its flexible twigs are sometimes used as cords for lashing. In the U.S., nurseries continue to sell Chinese Privet, and it remains recommended for in several planting guides.

In addition, Chinese privet has also been used in traditional herbal medicine. The decoction of privet leaves or bark helps treating diarrhea, stomach ulcers, chronic bowel problems, chapped lips, sore mouths and throats, and a wash for skin problems. Privet leaves and bark have bitter properties that make a useful tea for improving appetite and digestion in chemotherapy patients.

Economic and Cultural Impact
Privet produces a fruit, which is toxic to humans. Symptoms from eating privet fruit include nausea, headache, abdominal pain, vomiting, diarrhea, weakness, low blood pressure and low body temperature. . Additionally, in large amounts, the odor produced from privet’s flowers can cause respiratory irritation The pollen produced from these flowers is known to cause an allergic reaction with some people Privet removal and management has proven to be costly for control agencies. For example privet is a large problem in New Zealand and the east coast of Australia (Ligustrum lucidum, Ligustrum sinense and Ligustrum vulgare[7]). It is banned from sale or cultivation in New Zealand because its pollen is known to cause asthma and eczema in sufferers. Additionally, Privet is one of several plants that are poisonous to horses and is poisonous to most pets.

When privet is a nonnative invasive species, the cost of controlling and removing privet creates an economic impact that is problematic for conservation efforts. The annual cost of removing Chinese privet in the United States is estimated to be $737 per acre when a mulching machine and two-person herbicide application crew are employed. The cost of foliar glyphosate applications on privet is also very expensive, and the costs for the treatment ranges from $130 per acre for chemical and surfactant costs.

Ecological Effect
A plant may produce thousands of fruits, most of which are eaten by birds. Privet is used as a food plant by the larvae of some Lepidoptera species including Common Emerald, Common Marbled Carpet, Copper Underling, the Engrailed, Mottled Beauty, Scalloped Hazel, Small Angle Shades, The V-pug and Willow Beauty.

Invasiveness
Privet is a successful invasive species because of its ability to outcompete and therefore displace native vegetation. This competitive superiority to native vegetation have been connected with the plants ability to adapt to different light conditions. For example when in low light environments privet is able to produce fewer and larger ramets than its competitors This lends it more tree like qualities that allow it to more effectively compete for light. It is an ideal invasive species because it reproduces both sexually and asexually. Through sexual reproduction, privet produces seeds that are easily dispersed through wind and animals. These seeds can rapidly colonize disturbed soil such as that disturbed by fires, forest clearings, erosion, or abandoned agricultural land. Additionally, privet matures quickly, which allows for a short generation cycle and even greater dispersal as a species. Finally, the roots of privet can reproduce asexually through root suckers. This vegetative reproduction makes privet difficult and costly to control because root fragments left in the soil can sprout and grow new plants. ) Evidence suggests that climate changes, brought about by due increased CO2 concentrations, can increase the spread and proliferation of privet. This is because climate change is predicted to increase competition between native and nonnative plants and because increased temperatures may expand the range of plants, such as privet, that are typically restricted warmer climates.

Ecological Impact in the U.S.
The full ecological effect of privet is still being studied. However, data suggests that privet tends to decrease native plant and animal growth and diversity. In a study by Greene and Blossey using field observations and a transplant experiment it was found that there was a significant negative correlation between percent Chinese Privet cover and   herbaceous cover, species richness, and plant height in cm. In a comparison of two experimental gardens, each with four native plants, the plot with Chinese Privet contained almost entirely nonnative plants after 64 weeks. Out of approximately twenty plants per species, only a single individual of A. negundo,  C. latifolium, and  C. tribuloides survived the entire study when in the presence of Chinese Privet. Additionally, these lone surviving species had lower leaf-counts and stunted height relative to their counterparts in Privet-absent plots. No individuals of the original fourth B. cyclindrica survived.

When introduced to an ecosystem, privet grows quickly and, if given enough time, will produce a thick layer under the forest canopy that prevents sunlight from reaching the native plants below. In some cases, this can drive native populations to extinction. Forests containing large amounts of privet tend to have fewer trees, less shrub diversity, and decreased density of low herbaceous plants.

Insects are greatly affected by the proliferation of invasive species such as privet. For example, one study has found that the abundance and diversity of butterflies after privet removal increased almost to the level of that in a similar forest community, with no history of Privet invasion. Honeybees are another example of an organism whose numbers rely on the abundance of privet. In one study conducted in Georgia, it was found that privet decreases the diversity of native honeybee colonies. Based on an experiment where the number of honeybees in a controlled environment was compared with the number of honeybees in an environment invaded with privet, it was concluded that the removal of privet provided immediate benefits for the honeybees. Plots that were removed of privet resulted in four times as many bee species as control plots in which privet was not removed. Another example of how privet can have a negative ecological impact on communities can be seen on its ability to threaten two endangered species. (SchweintzOz sunBower and Miccosukee gooseberry) in the U.S.

It is predicted that if left unchecked privet may result in large-scale ecosystem modification and an overall loss of native species diversity and richness. For example, the Sierras Chicas of Cordoba have experienced widespread landscape change since 1970, such as forest fragmentation and urban growth. Furthermore, biological species invasion is considered a main component of global ecosystem change due to changes in biogeochemical cycles and disturbance regimes. Invasive species such as privet are known to alter the dominant vegetation type, soil properties, animal behavior, and the natural cycling of resources. For example, Chinese Privet has been found to increase the decomposition rate of leaf litter by 2.6-fold in riparian forests. However, because the usual method employed to study the impact of privet is to compare infected and uninfected areas, the current available data may be inaccurate. This is because these types of comparison studies have trouble controlling for abiotic and  biotic habitat conditions that could be negatively affecting native plant growth.

Methods of Control
The same qualities that allow Privet to outcompete native species make it extremely difficult to control and eradicate. Privet can be managed by mowing or cutting consistently, as closely to the ground as possible This will prevent the spread of the privet but will not eradicate it. There are no known biological controls of privet. Even methods such as controlled burning have proven ineffective. Indeed such methods actually aid privet growth because privet recovers more effectively than native plants from such controlled burns.

Mechanical removal of privet, especially for younger plants or smaller areas of growth, can prove effective. However, all of the root must be removed in order to prevent root re-sprouting. In addition, mechanical removal can prove difficult for more large-scale invasions. When such large invasions occur in the natural environment, herbicide use is eliminated due to the negative impacts on native plants. The use of many workers or heavy machinery such as bulldozers is the most effective option. The soil disturbance and resulting erosion are important considerations when using such measures.

When herbicide use is warranted several methods have proven effective. In all cases soil disturbance following herbicide treatment is inadvisable. This is due to privets preference for disturbed soils and its increased ability to compete in such an environment. The length these soils must be left undisturbed varies with the treatment. Foliar applications of glyphosate, cut-stump applications of glyphosate or triclopyr, and basal bark treatments for stems less than 0.5 inches have proven effective methods of herbicide application.

The foliar treatments are most effective against dense thickets of privet. The best time for such treatments are in late fall and early spring when many of the native species are dormant. Care must be used with such an application to avoid spraying non-target plants. This treatment is generally considered to be less effective than the cut-stump and basal bark methods.

The cut-stump method is most useful when treating single plants. This is method consists of thoroughly covering the stump of a recently cut plant with herbicides, such as glyphosate and triclopyr. The effectiveness of this treatment is increased by cutting a hole into the surface of the stump. Use of this treatment when the plant breaks the dormant stage as well as when the ground is frozen is advised against as it greatly reduces effectiveness.

The basal bark treatment consists of application of herbicide to all basal parts of the plant below 12-15 inches. The bark must be thoroughly wetted with herbicide for this treatment to be most effective. The USDA suggests that 25% triclopyr and 75% horticultural oil is the most effective herbicide composition for basal bark treatments.

Agencies Working to Control Privet
The Federal Interagency Committee for the Management of Noxious and Exotic Weeds (FICMNEW) engages with public and private organizations in the effort to combat noxious and exotic weeds, among which are Chinese and European Privet The Privet is more actively on the agenda of the US Forest Service via their Invasive Species Program US Forest Service and the National Park Service via deployment of their Exotic Plant Management Teams, each team with jurisdiction over ten or so national parks, and working with local volunteers, contractors and service organizations.