The document discusses key concepts in ecology including ecosystems, community ecology, population ecology, and seed dispersal. It defines ecology as the scientific study of interactions between organisms and their environment. An ecosystem is described as a biological community of interacting organisms and their physical environment. The document outlines different types of seed dispersal vectors including gravity, wind, water, animals, humans, and explosion. It provides examples to illustrate concepts like food chains, food webs, predator-prey relationships, and symbiotic relationships between species.

1. Presenters:
HADIA KHADIJA
ID#04021613013
MARIA RASHEED
ID#04021613040
Department : BS-ZOOLOGY QAU ISLAMABAD

2. ECOSYSTEM
ECOLOGY
COMMUNITY ECOLOGY
POPULATION ECOLOGY
INTRODUCTIONTO SEED DISPERSAL

3. What is ECOLOGY?
The term ecology
 Coined by German zoologist Ernst Haeckel in 1866.
 Comes from the Greek words oikos, meaning “house or environment” and
logy, meaning “the study of”.
 Ecology is the scientific analysis and study of interactions among organisms
and their environment.
3 9/8/2021 Add a footer

4. What is ECOSYSTEM?
The term ecosystem
 Coined byArthur GeorgeTansley in 1935.
 Comes from Greek words oikos meaning, “house or
environment” and systema meaning, “organized body”
or a collection of related parts that function as a unit.
 An ecosystem is a community of living organisms (biotic
components like animals, plants, fungi, micro-organisms)
in conjunction with the non-living components (abiotic
components things like air, water and mineral soil) of
their environment, interacting as a system.
4 9/8/2021 Add a footer

5. ECOSYSTEM ECOLOGY:
 Ecosystem Ecology is the integrated study of living
(biotic) and non-living (abiotic) components of
ecosystems and their interactions within an
ecosystem framework.
 This science examines how ecosystems work and
relates this to their components such as chemicals,
soil, plants and animals.
5 9/8/2021 Add a footer

6. Population Ecology (Autecology):
• Studying a single population’s relationship to its environment it will be called
as population ecology or autecology.
• For example , you are studying 50 to 100 plants of sunflower in order to know
the effect of water pollution on their growth and yield, you are studying the
single or one population of sunflower plant.
6 9/8/2021 Add a footer

7. Community Ecology (Synecology):
• The study of the relationship of different
communities (grouping of populations) to their
environment is called community ecology or
synecology.
• Community ecology seeks to understand how
species interact by studying many different kinds
of relationships between organisms.
7 9/8/2021 Add a footer

8. 8 9/8/2021 Add a footer

9. Biotic and Abiotic Components:
BIOTIC COMPONENTS
• A biotic factor is any living
component that affects the
population of another organism, or
the environment.
• This includes animals that consume
the organism, and the living food
that the organism consumes.
• Biotic factors also include human
influence, pathogens, and disease
outbreaks. Each biotic factor needs
energy to do work and food for
proper growth.
ABIOTIC COMPONENTS
• Abiotic components or Abiotic factors
are non-living chemical and physical
parts of the environment that affect
living organisms and the functioning of
ecosystems.
• Abiotic components include physical
conditions and non-living resources that
affect living organisms in terms of
growth, maintenance, and
reproduction.
• All non-living components of an
ecosystem, such as atmospheric
conditions and water resources, are
called abiotic components.
9 9/8/2021 Add a footer

10. Biotic and Abiotic Components:
BIOTIC COMPONENTS
• The major Biotic components of
ecosystem are:
1. Producers
2. Consumers
3. Decomposers
ABIOTIC COMPONENTS
• Abiotic components are mainly of
two types:
1. Climatic factors : include rain,
temperature, light, wind etc.
2. Edaphic factors : include soil, pH,
Topography, minerals etc.
10 9/8/2021 Add a footer

11. 1.PRODUCERS(Autotrophs or
Self-Feeders):
 Make their own food from compounds that are obtained
from their environment.
 Are the source of all food in an ecosystem.
 On land most producers are green plants.
 In freshwater and marine ecosystems, algae and plants are
the major producers near shore lines.
 In open water, the dominant producers are phytoplankton
(most of them microscopic) that float or drift in the water.
e.g. dinoflagellates and diatoms.
 Most producers capture sunlight to make carbohydrate
(such as glucose) by photosynthesis.
11 9/8/2021 Add a footer

12. 2.CONSUMERS(Heterotrophs):
 Get their energy and nutrients by feeding on other organisms or their
remains.
i. Primary consumers: are those that eat producers (plants) as a source
of food.They are also known as herbivores.
ii. Secondary consumers or carnivores: eat other animals.
iii. Tertiary consumers : large carnivores which feed on secondary
consumers.
iv. Quaternary consumers: largest carnivores that feed on tertiary
consumers.They are not eaten by any animals.
v. Omnivores: have mixed diet that include both plants and animals.
12 9/8/2021 Add a footer

13. 3. DECOMPPOSERS(Saprotrophs):
 Are mainly the fungi and
bacteria, which obtain their
energy from the dead and
decaying plants and animals
and recycle organic matter in
ecosystem.
 They release chemical
elements as ions.
 The main chemical ions are
nitrates, ammonia, phosphates,
potassium and calcium.
13 9/8/2021 Add a footer

14. FOOD CHAIN:
 The transfer of food energy from its basic source in
plants through a series of organisms , each of which
eats the preceding and is eaten by the following is
known as food chain.
 Transfer of food through various trophic levels of an
ecosystem.
14 9/8/2021 Add a footer

15. FOOD WEB:
 Interlocking
pattern of different
food chains.
 The combination of
many food chains.
 The variety of
pathways in a food
web helps to
maintain the
stability of the
ecosystem.
15 9/8/2021 Add a footer

16. The flow of energy in food chain of an ecosystem
• Main source of energy in an ecosystem is sun.
• Most life on earth depends on photosynthetic
organisms which capture sunlight and convert
it into chemical energy in organic molecules.
• Producers use most of the energy they make
for themselves.
• All other organisms in an ecosystem are
consumers.
• Consumers eat plants or other organisms to
obtain their energy.
• Energy move from one trophic level to the
next, from sunlight to- producer – to primary
consumer and so on, down the food chain.
16 9/8/2021 Add a footer

17. 17 9/8/2021 Add a footer

18. RELATIONSHIPS
Predation
Symbiosis

19. PREDATION (predator-prey relationship):
• An animal that preys on other animals is a predator.
• A predator is a consumer.
• The animal that is caught and eaten is the prey.
• The over all process is called predation.
• Examples : cat/mouse , fox/rabbit , seal/fish , frog/mosquito etc.
19 9/8/2021 Add a footer

20. SYMBIOSIS:
• It describes a close relationship between two organisms
from different species.
Kinds of Symbiosis :
• Mutualism
• Commensalism
• Parasitism
20 9/8/2021 Add a footer

21. MUTUALISM:
• It is the relationship between two organisms in which both the
organisms benefit from each other.
• Example
 Dogs and humans have enjoyed a mutualistic symbiosis for
centuries:
The dogs supply protection and companionship and the
humans provide food and shelter.
 Lichen is a relationship between a fungus and an alga:
Fungus provide shelter and mineral ions to alga and alga supply
nutrients and oxygen.
21 9/8/2021 Add a footer

22. Commensalism:
• It is the relationship between two organisms where one gets benefit from the
other.The other is not helped but is not harmed or damaged from the
relationship.
• Example
 Sharks may have small fish called remoras attached to them:
As the shark feeds, the remoras pick up the scraps.The remoras benefit from
this relationship, shark is not affected at all.
 A spider building a web on a tree.
22 9/8/2021 Add a footer

23. PARASITISM:
• In parasitism, one organism benefits from the
relationship but at the expense of the other.
• This is an association between a host and a parasite,
which involves providing the parasite with food,
protection and conditions for survival.
• Examples
 Fleas and mosquitoes feed on blood from other
organisms.
 Tapeworms :Tapeworms do more damage to their
hosts because they eat partially digested food and that
deprives the host of some food and nourishment.
 Barnacles that attach to the bodies of whales :The
whale is not harmed greatly, but may have some pain or
itching.
23 9/8/2021 Add a footer

24. BIOGEOCHEMICAL CYCLES:
24 9/8/2021 Add a footer
• Energy flows through an
ecosystem and is dissipated as
heat, but chemical elements are
recycled.
• The ways in which an element—
or compound such as water—
moves between its various living
and nonliving forms and locations
in the biosphere is called
a biogeochemical cycle.

25. 25 9/8/2021 Add a footer

26. NITROGEN CYCLE:
26 9/8/2021 Add a footer

27. 27 9/8/2021 Add a footer

28. Introduction to
Seed Dispersal
Seed Dispersal by various vectors

29. SEED DISPERSAL:
• Seed dispersal is the movement or transport of seeds away from the parent
plant.
• Plants have very limited mobility and consequently rely upon a variety of
dispersal vector to transport their propagules, including both
abiotic and biotic vectors.
• Major vectors for seed dispersal are:
1. By Gravity
2. ByWind
3. ByWater
4. By Animals
5. By Humans
6. By Explosion
29 9/8/2021 Add a footer

30. Seed Dispersal by Gravity:
• If they have a tough outer shell, they may roll
some distance from the parent plant.The higher
up the tree they are, and the larger they are, the
further they can roll.
• If they have a soft skin, they may break open
when they hit the ground and the individual
seeds may be scattered.
• On lower-growing plants, many fruits and seeds
are also heavy enough to fall to the ground
without any other help.
• When they reach the ground, some seeds are
taken further from the parent plant by animals or
water.
30 9/8/2021 Add a footer

31. Seed Dispersal byWind:
• Some seeds are carried to a new
place by wind.These seeds are very
light.
• The seeds of orchid are as fine as
dust.
• Many have hairy growths which act
like little parachutes and carry the
seed far away from the parent
plant.
• The seeds of dandelion are carried
by the wind.
31 9/8/2021 Add a footer

32. Seed Dispersal byWater:
• Plants which grow beside water often rely on water to transport their seeds
for them.
• They may produce light seeds which float, or there may be fluff that helps
buoyancy.
• Water lily and coconut palm are carried by water.
32 9/8/2021 Add a footer

33. Seed Dispersal by Animals:
• The animals eat the fruit but only the juicy part is digested and seeds are
deposits which are dropped several miles away.
• Blackberry , cherries and apple seeds are dispersed in this way.
• Some fruits like that of burdock plant have seeds with hooks.
• These catch on fur of animals and are carried away.
33 9/8/2021 Add a footer

34. Seed Dispersal by Humans:
• Humans mostly dispersed the seeds in farms
by hands.
• Various seeds stuck with the socks, shoes
and clothes and carried miles away.
34 9/8/2021 Add a footer

35. Seed Dispersal by Explosion:
• Some plants have pods that explode when ripe and shoot out the seeds.
• Lupins, gorse and broom scatter their seeds in this way.
• Pea and bean plants also keep their seeds in a pod.When the seeds are ripe
and pod has dried , the pods bursts and open and the peas and beans are
scattered.
35 9/8/2021 Add a footer

36. 36 9/8/2021 Add a footer