According to Daniel Simberloff
“An invasive species is
one that arrives (often
with human assistance) in
a habitat it had not
previously occupied, then
establishes a population
and spreads
autonomously.”
• Disruption of Local Ecosystems
• Alteration of Ecosystem Dynamic
• Spread of Diseases
•Alien species often
compete with native
plants for resources
such as light, water,
and nutrients.
Alien species can
disrupt existing
ecological
relationships.
•Alien species can
introduce new pests
or diseases to which
native plants have
little resistance.
COMMON WATER HYACINTH
Water hyacinth prevented
sunlight from reaching
underwater. Plants and algae
could not grow, preventing
fish from feeding and
reproducing.
COGON GRASS
Can survive a wide range of
environmental conditions, and its
allelopathic effects and
pyrogenic nature, allow it to
exclude native plant species and
other desirable plants and
dominate large areas of land.
MAHOGANY TREE
Has an allelopathic effect; it
produces chemicals that inhibit
the growth of surrounding
vegetation. When used in
reforestation, it will colonize the
area for it grows so fast that it
will dominate the local species.