This document discusses exotic species, also known as non-native or introduced species. It defines exotic species as living outside their native range and describes various ways species can be transported, such as through stowaways, subsistence and commerce, recreation, science, and habitat changes. It then discusses some impacts of exotic species, including them acting as predators, grazers, parasites, pathogens, competitors, and hybridizing with native species. Finally, it notes exotic species can significantly alter ecosystem properties and functions.

1. Presented To : Dr. Khalid Nawaz
presented By: Maryam Ijaz
Bs Botany 4th Semester

2. Exotic species

3. Exotic species
• Exotic species are those species
living outside of its native home
range.
• Many botanist refer to alien or
adentive species where as biological
invaders introduced species non
native species and non indigenous
species.
•.

4. So biologist use this term if a species is
present outside of its natural geographic
range where as non biologist called the
exotic species.

5. How species move ?
There are different ways for transfer of
exotic species .
Stowaways
 Subsistence and Commerce
Recreation
Science
Biological control
Habitat /climate change

6. Stowaways
Large portions of the species that have
transferred around the world were
stowaways.
Species that have greatly left behind.
Stowaways often go unnoticed because
they are in very small and inconspicuous.
Travelling as eggs, pupa spores on food
or on roots of plants .

7. Earthworms

8. Subsistence and Commerce
Most deliberate attempts to combine worlds
biota have been motivated by our needs for
food.
Colonist every where have brought their
own domestic plants and animals with them
and often sent back new plants and animals
to their home range .

9. Conti……..
 In Europe colonization results in
transportation of potatoes, corn went back to old
world on the same ship that were introducing
horses, wheat and many other species.
Species for food dominate the list of planned
introducing but other needs also have
introduction.
So wild species are important for commercial
purposes.

10. potatoes

11. Recreation
Support hunters and anglers have been
primary catalyst for planned introduction of
exotic wild species.
In California 50 species out of 133 fresh
water fishes are not native to state. people
dumped new species of fishes into almost
every water body that they visit regularly
including both game fishes and smaller
fishes for food and gaming

12. Science
To study closely scientists often
establish breeding colonies in their
laboratories sometime these species are
outside of their native range and
sometime they escape.
Example : Gypsy moth

13. Gypsy moth

14. Habitat loss/ climate
change
• When we think of exotic we usually
think of species actually transported
by people deliberately or accidently
but we could include species that are
able to expand their home range
themselves because of human
changes to environment.

15. Impacts of exotic species
• Most exotic species are leaving environment
so completely manipulated by people that
their direct impacts on native biota are not
very severe. Unfortunately there are
thousands of exceptions to this organization
some of which are following:

16. Predators and grazers
• It is easy to understand the impact of
exotic species when an introduces
species kills and eats native
species.From economic perspective
introduced insects that can consume
crop plants are among most
destructive exotic pests.

17. Parasites and pathogens
• Exotic parasites and pathogens have
a tremendous potential to effect
native predators and parasites feed
on the protoplasm of other species.
• European colonist killed far more
natives of Australia and Americans
with their diseases than their guns.

18. Competitors
• The effects of exotics as Competitors
are most prominent with plants and
other sessile species.
• Some exotic species can become so
extremely abundant that
competition for space is closely tied
to basic resources such as;
• water, nutrients,and light.

19. Hybridization
• Some introduced species are so closely related
to the native species that they may interbreed
and produce hybrids.
• The genes of one species come to dominent in
a common gene pool largely excluding the
genes of second species.This process is called
gene swamping.

20. Impacts on ecosystem
Impacts of exotic ecosytem can reach far
beyond the individual species that must
cope with a predator,competitor,pathogens
or parasite.
Exotic species can alter a variety of
ecosystem properties such as productivity
,nutrient cycling,soil and vegitation
structure.

21. • Exotic plants can also exchange the
entire ecosystem in many ways for
example nitrogen fixing plants can
significantly change the soil chemistry
of the environment.
• They invade fire prone exotic plants.
Exotic plants can allow fire to burn
more exteremly and entirely change
ecosystem.