Kudzu

(Pueraria montana (Lour.) Merr.)

Introduction:

Kudzu first made entrance into the United States in 1876 at the Philadelphia Centennial Exposition, and farmers begin planting it in the south in the period 1935-1950 to combat erosion (Bergmann & Swearingen, 2005). In the period 1900 to 1950 government agencies gave over 85 million seedlings to landowners in the southeastern United States (Forseth, Jr. & Innis, 2004). In 1953, the USDA removed kudzu from a list of acceptable to use ground cover plants (Bergmann & Swearingen, 2005). In 1970, kudzu was officially labeled as a pest weed, and in 1997 the plant was added to the Federal Obnoxious Weed List (Blaustein, 2001, as cited by: Forseth, Jr. & Innis, 2004).


Ecological Significance:

Kudzu vines grow rapidly and are commonly found throughout the Southeastern United States (Bergman & Swearingen, 2005; see also Figure 1 from Forseth, Jr. & Innis, 2004). Perhaps you have seen their green, strangling grip climbing up trees, mountains, and even vacant houses. Kudzu is able to spread quickly and overpower natural communities partially because most of its resources go into growth and leaves instead of supports, it has a high leaf level photosynthetic rate, it can move its leaves rapidly to orient them to the sun to increase the efficiency of light use, it can move a lot of water up through its roots, and it has the ability to fix atmospheric nitrogen (Forseth, Jr. & Innis, 2004). As a result of these unique abilities, kudzu is a strong competitor for native species and hard to get rid of once it has been introduced (Forseth, Jr. & Innis, 2004). Additionally, because a lot of the carbon that kudzu takes up goes to roots, it has the ability to take root wherever it can find soil (Forseth, Jr. & Innis, 2004). As a result of the vine’s immense root structure, it can take large amounts of water from the soil, which could leave other native species without water during drought periods (Forseth, Jr. & Innis, 2004).

Kudzu is typically classified as a Rank 1: Severe Threat Species (Forseth, Jr. & Innis, 2004). The vine damages native plants by covering them and preventing them from obtaining sunlight and carbon dioxide, and it can even uproot trees and shrubs by its massive weight (Bergman & Swearingen, 2005).

Policy Implications and Control:

The most effective way to curb the growth of kudzu is to get rid of the roots, although other methods of control include physical cutting or mowing, feeding to cows and other livestock, burning, or removing to a landfill, as well (Bergman & Swearingen, 2005). Herbicides can also be effective agents for controlling kudzu, and the United States Forest Service is searching for biological controls (Bergman & Swearingen, 2005).

Kudzu can have multiple negative economic effects, and many organizations spend a lot of money controlling kudzu, including National and State Parks, and Railroad companies that must prevent the vine from growing over rails which could result in slipping of trains (Forseth, Jr. & Innis, 2004). However, because private properties do not keep the vine in check, oftentimes control efforts on public lands are ineffectual (Forseth, Jr. & Innis, 2004).

Other Native Trees and Shrubs:

Kudzu is known to uproot native trees and shrubs, and also essentially smother them by covering them up and preventing access to resources such as sunlight and carbon dioxide (Bergman & Swearingen, 2005). Some native trees and shrubs in this area that could potentially be effected by kudzu vine might include oaks, maples, and pines.

 

Pictures taken in Georgia by Jack Anthony: http://www.jjanthony.com/kudzu/sculptures.html

 

Photo: Jim Heget, 2002: http://www.morgan.k12.il.us/jvsd117/herget/tree_id.html

Photo: Jim Heget, 2002: http://www.morgan.k12.il.us/jvsd117/herget/tree_id.html

 

Native plants that share similar distribution to kudzu are likely to be impacted by this invading vine, and efforts to protect these native species should include the removal or control of kudzu.

 

 

 

 

 

 

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