What Is The Extent and Consequences of Ligustrum sinense Invasion By Alex Neville
Origins • Ligustrum sinense is commonly known as Chinese Privet. • Introduced to the US in 1850
Uses • Ornamental • Hedge, Mass Plantings, Single for floral displays
Plant Characteristics • Member of the Olive Family (Oleacea) • Flowers in May • Fruit is toxic to humans • Cause symptoms such as nausea, headache, abdominal pain, vomiting, diarrhea, weakness, and low blood pressure and body temperature • Floral odors cause respiratory irritation
The Threat • Rapid maturation • Prolific seed production • Reproduce vegetatively using suckers • Can tolerate wide range of light and soil conditions • Quickly invades disturbed habitats
Newly Colonized Areas • The rapid and recent spread in Oklahoma
Expansion • Chinese Privet is thought to have escaped cultivation by the 1930’s Current Distribution
Effects • Has the ability to out-compete and eventually displace other plant species • Can reduce plant diversity • Can therefore reduce the diversity of plant-dependent species
Specific Cases • According to the U.S. Fish and Wild Life Service Chinese Privet is one of the major factors pushing Schweintz’s Sunflower towards extinction.
Specific Cases • A study done in the UCA Nature Preserve found 19 out of 20 randomly selected 3 m by 3 m plots in the riparian zone contained privet
Specific Cases • Effects of Ligustrum sinense Lour. (Chinese Privet) on Abundance and Diversity of Songbirds and Native Plants in a Southeastern Nature Preserve by Joshua Wilcox and Christopher Beck • “In contrast, abundance and richness of native plants were reduced in high privet-density plots. Our results suggest that removal of privet would improve native plant communities.”
Control • Extremely difficult once privet is established • Due to: • Large seedbank • Seeds are spread by birds • Need to remove underground parts as well
Control • When in small numbers, removal by hand • Direct herbicide treatments • Basal-bark or cut-surface treatments • Must avoid disturbance for a year afterwards, to allows the herbicide to take out the whole plant • Most effective treatment is cutting, then application of herbicide to the stump • Fire is not feasible, since the disturbance it provides allow for increased invasion by privet. • Do UCA prairie burns aid in expanding privet populations?
Controls • Biological controls • Macrophya punctumalbum is a known pest in Europe • Privet is susceptible to Pseudocercospora ligustri, which causes fungal leaf spot • Also vulnerable to common root crown bacteria, Agrobacterium tume-faciens
Summary • Chinese Privet is a highly invasive exotic species • The plant has spread through most of the southeast • Consequences of invasion are reduced plant diversity • Reduction of privet numbers is essential to maintain diversity • Control of privet populations is very difficult and labor intensive • Best control is cutting the plant, and then applying herbicide to the stump
Sources • http://www.bioone.org/perlserv/?request=get-document&doi=10.1656%2F1528-7092(2007)6%5B535%3AEOLSLC%5D2.0.CO%3B2&ct=1 • http://plants.usda.gov/plantguide/doc/pg_lisi.doc • http://www.invasive.org/eastern/species/3035.html • http://www.thewildclassroom.com/biodiversity/problemplants/species/Chinese%20Privet.htm