Non-Native Invasive Plants
Transcript of Non-Native Invasive Plants
Non-Native Invasive Plants
Invasive Species Primer
A non-native plant occurs outside its
normal range
Not all non-native plants have negative
effect, some are harmless or even beneficial
Definition
Criteria of invasive plants
◦ Habitat: Colonize natural and semi-natural
habitat
◦ Effect: Negative impacts on the ecosystem,
biodiversity, human health and economy
◦ Population: Expanding in distribution and
abundance
Occurrence of Clidemia hirta, a shrub originated from Tropical America
Intentional
◦ Brought to a new region for ornamental,
medicine, dye, food and erosion control amongst
others
Dispersion
Accidental
◦ Plant propagules adhere to human, transport or
animals, transported in ship ballast, dispersed via
livestock, mixed with crop seeds and spread from
gardens
Negative effects on biodiversity
◦ Compete with native plants for resources
◦ Alter habitat structure and local species richness
◦ Resulting in reduction in biodiversity and increase
in dominance
Impacts
Consume limited resources otherwise
available for native species
◦ Take up ground water and nutrient
◦ Cover large amount of space resulting in
exclusion of local species
Disrupt ecosystem process encompassing
biological interaction and abiotic characters
◦ Pollination
◦ Frugivory
◦ Succession
◦ Fire regimes
Clidemia hirta
◦ Originated from
Tropical America
◦ Threatens endemic
island species e.g.
Hawaii and Fiji
◦ Potentially alter forest
regeneration
Examples
Piper aduncum
◦ Originated from South
and Central America
◦ Dense colony
excludes native flora
◦ Habitat for agricultural
crops pathogens
Mimosa pigra
◦ Originated from
Central America
◦ Block irrigation and
reduce grazing land
◦ Disable accessibility
to wetland
Physical
◦ Adapted the method in agriculture such as
mowing, pulling, cutting and tilling
Chemical
◦ Use herbicide to kill invasive plant by decreasing
the plant ability to grow and survive
Control