An ecosystem consists of all the living organisms (biocoenosis) and non-living components (biotope) that interact in a particular area. Organisms within an ecosystem are organized into populations of the same species and communities of different species, and they engage in trophic relationships where some organisms act as producers, primary consumers, secondary consumers, tertiary consumers, or decomposers. Ecosystems can be classified as terrestrial or aquatic and are sometimes grouped into larger biomes, while the biosphere encompasses all ecosystems globally. Ecosystems experience natural changes over time but are also impacted by human activities like pollution, overfishing, and deforestation.

1. UNIT 3.
ECOSYSTEMS

2. 1. What is an ecosystem?
A place and the organisms that live in this
place form an ecosystem.
BIOTOPE
Includes all the non-
living things in an
ecosystem (soil, water,
stones…)
BIOCOENOSIS
Includes all the living
things in an ecosystem
(plants, animals…)
The living things that live in an ecosystem form
GROUPS
POPULATION
It`s a group of
animals of the same
species that live
together
COMMUNITY
It`s a group of
different species
that live in the same
place

3. 2. What are trophic
relationships?
It is the relationship between the organisms
that eat and the organisms that are eaten.
PRODUCERS:
They produce
their own food.
Ex. Plants.
PRIMARY
CONSUMERS:
They eat plants
(herbivores)
Ex. caterpillar
DECOMPOSERS:
They break down
dead organisms.
Ex. Fungi and
bacteria
SECONDARY
CONSUMERS:
They eat herbivores
(carnivores)
Ex. Praying mantis
TERTIARY
CONSUMERS:
They eat carnivores
(carnivores)
Ex. owl

4. Food chain

5. 3.How do we classify
ecosystems?
TYPES OF
ECOSYSTEMS
TERRESTRIAL AQUATIC
Oceans, lakes,
rivers, ponds…
Rainforests, forest,
dessert,
grassland…

6. 4. What`s the biosphere?
The place where a population lives is
called HABITAT.
Some ecosystems have several types
of habitats. They are called BIOME.
The biosphere is all the ecosystems
and habitats on the Earth.

7. Individual
Individual

8. 5. Why do ecosystem
change?
Ecosystems change. Sometimes the
changes are natural, but sometimes
they are caused by human activity.
NATURAL CHANGES CHANGES CAUSED BY
HUMANS
-Seasonal changes
- Fires because of
hot summers
-Pollution
-Overfishing
-Forest fires
-Deforestation