community of plants, animals and other organisms that are linked by
energy and nutrient flows and that interact with each other and with
the physical environment.
Introduced species—An organism that has
been brought into an area where it does not normally occur. Most
introductions are caused by human activity. Introduced species often
compete with and cause problems for native species. An introduced
species is not necessarily an invasive species. Also called exotic,
non-native, or alien species.
Invasive species—A species that is non-native
to the ecosystem under consideration and whose introduction causes
or is likely to cause economic harm, environmental harm, or harm
to human health. Invasive species tend to grow rapidly and spread
easily, and frequently out-compete native species for space and
resources. An invasive species may be introduced or may spread outside
its normal range through natural processes.
Native species—A species that occurs naturally
in an area (i.e. is not introduced.)
Northern snakehead (Channa argus) are aggressive predators that
feed opportunistically on amphibians, fish, aquatic birds, and,
on occasion, small mammals. Of greater concern is the snakehead
fish's ability to survive in waters with low dissolved oxygen and
to travel across land
U.S. Geological Survey, Florida Integrated
Non-indigenous species—With respect to a
particular ecosystem, any species that is not naturally found in
that ecosystem. Species introduced or spread from one region of
the U.S. to another outside their normal range are non-indigenous,
as are species introduced from other countries or continents.
Non-native species—See introduced species,
invasive species, and non-indigenous species.
Noxious species—A plant species that is
undesirable because it is troublesome and difficult to control.
Not to be confused with species declared noxious by law (see noxious
Noxious weed—A plant defined by law as being
especially undesirable, troublesome, and difficult to control.
Nuisance species—A species that threatens
the diversity or abundance of native species or the ecological stability
of an infested area, or that threatens commercial, agricultural,
aquacultural or recreational activities dependent on such an area.
Species—A group of organisms that differ
from all other groups of organisms and that are capable of breeding
and producing fertile offspring. This is the smallest unit of classification
for plants and animals.