[5] 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.
[5] These seeds can rapidly colonize disturbed soil such as that perturbed by fires, forest clearings, erosion, or abandoned agricultural land.
[5] This vegetative reproduction makes privet difficult and costly to control because root fragments left in the soil can sprout and grow new plants.
[5] Currently privet is designated as a foreign invasive plant in Alabama and Georgia and considered a severe threat in North Carolina and Florida.
[3] It is estimated that Chinese privet alone occupies over one million hectares of land across 12 states ranging from Virginia to Florida and west to Texas.
However, data suggest that forests containing large amounts of privet tend to have fewer trees, less shrub diversity, and decreased density of herbaceous plants.
[12] When introduced to an ecosystem, privet grows quickly and, given time, will produce a thick layer under the forest canopy preventing sunlight from reaching the native plants below.
[5] If left unchecked, privet may result in large-scale ecosystem modification and an overall loss of native species diversity and richness.
[11] Out of approximately twenty plants per species, only single individuals of Acer negundo, Chamaenerion latifolium and C. tribuloides survived the entire study when in the presence of Chinese privet.
[11] Surviving plants had lower leaf counts and stunted height relative to their counterparts in privet-absent plots.
[16] Invasive species such as privet are known to alter the dominant vegetation type, soil properties, animal behavior, and the natural cycling of resources.
[17] However, because the usual method employed to study the impact of privet is to compare invaded and non-invaded areas, available data may be inaccurate.
[4] 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.
Additionally, the increased temperatures that result from climate change are predicted to expand the range of plants typically restricted to the deep south where it is warm and moist.
[18] Thus, states that are currently free from privet invasion (Michigan, Ohio, Indiana, Illinois, Kentucky, Virginia, Pennsylvania, etc.)
[5] When such large invasions occur in the natural environment, herbicide use is usually avoided due to the negative impacts on native plants.
[19] 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.
[19] The USDA suggests that 25% triclopyr and 75% horticultural oil is the most effective herbicide composition for basal bark treatments.
[22] Each team has jurisdiction over ten national parks and works with local volunteers, contractors, and service organizations.