1. Ecosystems and Communities
Chapter 4
Ecosystems and Communities

2. Ch 4.1 Objectives Differentiate between weather and climate
Identify the factors that influence climate

3. Weather vs. Climate
Weather is the day to day conditions of Earth’s atmosphere
Climate refers to average conditions over long periods
Defined by year after year patterns of temperature and precipitation

4. Microclimates Areas within a region can vary in their climate
Ex: southern exposure, changes in elevation, land bordering large bodies of water

5. Factors that Affect Climate
Solar energy trapped in the biosphere
Latitude
Transport of heat by winds and ocean currents

6. Temperature
Earth’s average temperature is determined by the balance of heat that stays in the biosphere and that which is reflected back to space
Greenhouse gases, like CO2, cause more heat to be trapped near Earth’s surface

7. The Greenhouse Effect

8. Latitude and Solar Energy
The angle at which the sun’s rays reach the Earth creates 3 distinct regions of climate: tropical, temperate and polar
Seasons are created by the tilt of the Earth

9. Effect of Climate on Biomes

10. Ch 4.2 Niches and Community Interactions
Define niche
Describe the role competition plays in shaping communities
Describe the role predation and herbivory play in shaping communities
Identify the three types of symbiotic relationships in nature

11. Niche
Organisms occupy different environments because each has a range of conditions under which it can grow and reproduce
Every organism has a unique range of tolerance

12. stress
stress
Tolerance for environmental conditions helps determine an organism’s habitat- general place where an organism lives

13. Niche
An organism’s niche describes not only what it does, but how it interacts with the biotic and abiotic parts of its environment
This includes:
Place in food web
Environmental conditions it needs to survive
Type of food it eats
How it obtains food
Other species that use it as food
When and how it reproduces
What is the niche of a bullfrog?

14. Niche
Competitive Exclusion Principle - no two species can occupy the same niche in the same habitat at the same time
Sharing a niche results in competition in nature often results in winner and loser – losing organism fails to survive
Different species can occupy similar niches.
Resource partitioning helps organisms with similar niches avoid competition

15. Warbler Niches Cape May Warbler Feeds at the tips of branches
Bay-Breasted Warbler
Feeds in the middle
part of the tree
Cape May Warbler
Feeds at the tips of branches
near the top of the tree
Spruce tree
Yellow-Rumped Warbler
Feeds at the lower parts of the tree and bases of middle branches

16. Community Interactions
Competition- same or different species attempt to use an ecological resource in the same place at the same time

17. Community Interactions
Predation - one organism captures and feeds on another organism
Predator – the one killing and eating
Prey – the food

18. Community Interactions-Symbiosis
Symbiosis- an interaction between two species living close together
Three types:
Parasitism – one is harmed (host), one benefits (parasite)
Mutualism – both benefit
Commensalism – one is neutral, one benefits

19. Mutualism
Parasitism
Commensalism