Biology Unit 4 notes

1. Chapter 4
Ecosystems & Communities

2. •What is the difference between weather
and climate?
4.1Climate

3. The three main zones are the polar, tropical, and
temperate climates.
polar climate: the far northern and southern
regions of Earth
tropical zone: surrounds the equator
temperate zone: the wide area in between
the polar and tropical zones

4. The Greenhouse Effect
•Greenhouse gasses such
as carbon dioxide trap
heat in the Earth’s
atmosphere.

5. Every Organism has a habitat and
Niche
A habitat is the general place in
which an organism lives.
A niche describes not only the
place an organisms lives, but the
range of physical and biological
conditions in which it lives and
interacts.
4.2 Niches and Community
Interactions

6. The Competitive Exclusion
Principal
•If two species attempt to
occupy the same niche, one
species will be better suited
to obtain limited resources
and will eventually exclude
the other.
What would happen if two of these warbler species tried to occupy the same niche
at the same time?

7. Community Interactions
Predator-Prey
Herbivore-Plant

8. Symbiotic Species
Two or more species living together
in a close, long-term association.
Parasitism – the host is harmed
and the parasite benefits
Ex: lice, hookworm,
roundworms
Organism benefits
0
_
Organism is harmed
Hornworm
caterpillar
The host
hornworm will
eventually die as
its organs are
consumed
by wasp larvae.
Braconid wasp
Braconid
larvae feed on
their host and
release
themselves
shortly before
reaching
the pupae
stage of
development.
_
Parasitism
+
0

9. Mutualism – benefits both
participating species
Ex: Clownfish and sea anemone
Commensalism – one species
benefits, and the other is neither
harmed nor helped
Ex: Barnacles on a blue whale

10. 4.3 Succession
When new land is created, or a habitat is
destroyed by disaster a new habitat will be
created.
Succession is a regular progression of species
replacement.

11. Primary succession occurs where life has not
existed before.
Ex: A new volcanic island
Secondary succession occurs where there has been
previous growth.
Ex: A forest that has been burned
Untamed science
video

12. 4.4 Biomes
Biomes are described in terms of abiotic and biotic
factors.

13. Tropical rain forest
biomes produce lush
forests.
warm temperature
abundant precipitation all year
Source: World Meteorological Organization

14. Grassland biomes are where the primary
plant life is grass.
Temperate grasslands are dry and warm
during the summer; most precipitation
falls as snow.

15. Tropical grasslands (savanna) are warm through the
year, with definite dry and rainy seasons.

16. Desert biomes are characterized by a very
arid climate.
very low amount of precipitation
four types: hot, semi-arid, coastal, and cold

17. Temperate forest biomes include
deciduous forests and rain forests.
Temperate deciduous forests have hot summers and cold winters.
Deciduous trees are the dominant plant species.

18. The taiga biome is located in cooler
northern climates.
boreal forest
long winters and short summers
small amount of precipitation

19. The tundra biome is found in the far
northern latitudes with long winters.
winter lasts 10 months
limited precipitation
permafrost

20. 4.5 Aquatic Ecosystems
•Nearly ¾ of Earth’s surface is covered
with water.
•Aquatic organisms are affected
primarily by water depth, temperature,
flow, and amount of dissolved
nutrients.

21. •Freshwater ecosystems include moving
and standing water (wetlands, lakes and
ponds, and rivers and streams).

22. Estuaries are dynamic environments
where rivers flow into the ocean.
Mixture of fresh water with salt water
Serve as spawning and nursery grounds
for many fish and shellfish
Chesapeake Bay
Louisiana bayous
Florida Everglades

23. Estuaries are highly productive ecosystems.
Estuaries provide a protected refuge for many
species.
Estuaries are primarily threatened by land
development.

24. Marine Ecosystem
Intertidal Zone
Affected by tides
Costal Ocean
Coral reefs and kelp forests
Open Ocean
90% of ocean
Photic and Aphotic zones