1. Community Ecology
Packet #32
Chapter 14

2. Review & Introduction Community Community Ecology
Assemblage of populations, of different species, that live and interact in the same place at the same time
Community Ecology
Description and analysis of patterns and processes within the community

3. No independent species
Introduction II
Communities
Large numbers
Varying size
No precise boundaries
Rarely isolated
No independent species
Difficult to Study
Communities are difficult to study
Large number of organisms Communities vary in size
Lack precise boundaries
Rarely completely isolated
Within a community, no species exists independently of other species.

4. Community Structure & Functioning
Community Ecology
Community Structure & Functioning

5. Niche [nich]
The function or position of an organism or population within an ecological community.
The particular area within a habitat occupied by an organism. HW
What is a habitat?

6. Niche [nich] II
There are factors that impact/restrict the ecological niche of a species within a habitat.
Limiting resources
Abiotic factors
Soil composition
Climatic extremes
Any environmental resource that is scarce or unfavorable
Biotic factors

7. Competition Intraspecific Interspecific
Competition between members of same species
Interspecific
Competition between members of different species
Competition between two species with overlapping niches may lead to competition exclusion
Results in the exclusion of one species due to interspecific competition.

8. Natural Selection
Natural selection shapes the body forms and behaviors of both predator and prey
Pursuit and ambush
Chemical protection
Plant defense
Varied defense adaptations of animals to avoid predators
Fleeing
Hiding
Warning colors
Batesian mimicry
Resemblance of a harmless organism to a harmful or unpalatable organism
Mullerian mimicry
Similar morphology of a group of harmful or unpalatable organism
Monarch & Viceroy butterflies
Living in large groups

9. Community Ecology
Defense Mechanisms

10. Defense Mechanisms Hiding
Use of warning colors
Aposmatic Colors
A warning coloration such as a 'striking' color pattern designed to attract attention and to warn predators away.
Defense Mechanisms
Use of Warning Colors
Batesian Mimicry
Mullerian Mimicry
Hiding

11. Defense Mechanisms Hiding
Batesian mimicry
Resemblance of a harmless organism to a harmful or unpalatable organism
Defense Mechanisms
Use of Warning Colors
Batesian Mimicry
Mullerian Mimicry
Hiding

12. Defense Mechanisms Hiding
Mullerian mimicry
Similar morphology of a group of harmful or unpalatable organism
Monarch & Viceroy butterflies
Defense Mechanisms
Use of Warning Colors
Batesian Mimicry
Mullerian Mimicry
Hiding

13. Relationships within Communities
Community Ecology
Relationships within Communities

14. Intimate relationship b/t two or more species.
Symbiosis
Symbiosis
Mutalism
Commensalism
Parasitism
Intimate relationship b/t two or more species.
Any intimate relationship or association between members of two or more species
Greek sym = together
Greek bios = life

15. Types of Symbiosis I Mutualism Benefits are shared
Nitrogen fixing bacteria & legumes
Zooxanthellae and reef- building coral
Mycorrhizae facilitate mutalistic relationships between fungi and the roots of a wide variety of plants

16. Types of Symbiosis II Commensalism Taking without harm
Epiphytes living on tropical tress benefit from the habitat of the host, but the host is not harmed or benefited.
Cattle egrets and water buffalo

17. Types of Symbiosis III Parasitism Taking at another’s expense
Parasite benefits while host is harmed
Well adapted parasite does not kill the host
Parasite that causes the death of the host is a pathogen

18. Keystone Species Affect the character of the community
Have a great effect on other species in the community
Commonly are the top predators
Dominant species influence the community as a result of their greater size or abundance
Trees are the dominant species in forests because they change the local environment
Coral, an animal, in coral reefs
Cordgrass in salt marshes
Prairie grasses in prairies
Kelp in kelp beds

19. Community Development
Community Ecology
Community Development

20. Community Development—Succession
Primary Succession
Secondary Succession
One species replaced by another
How do communities develop?
The most studied and natural methods is known as succession.

21. Succession
Process of community development over time, with one species being replaced by another

22. Succession II Primary Succession
Occurs when a community develops in a “lifeless” environment
Occurs on bare rock when rock is eventually transformed into soil
Occurs on newly formed volcanic larva and recently glaciated rock

23. Succession III Secondary Succession
Occurs when a community develops where a previous community existed
Occurs where soil already exists
Areas denuded or modified by fire or agriculture
Abandoned farmland
Keep in mind that disturbances impact succession

24. Review

25. Review
Students are encouraged to place their own questions and charts on the following slides.