1. Ecology

2. Ecology
Relationships of living organisms to their environment

3. Ecological Concepts Environment Habitat Niche
All conditions directly affecting animals existence
Habitat
The physical space inhabited by an animal
Niche
The specific multidimensional sets of conditions that define where an organism can exist

4. Niche

5. Ecological Concepts
Populations
Communities
Ecosystems

6. Ecological Concepts - Populations
Reproductively interacting members of a single species
Deme –
Any particular population separate from other populations of a species
Demographics
Age structure, sex ratio, growth rates, etc…

7. Population Dynamics Population Growth rates Carrying capacity
Birth rate – death rate = intrinsic growth rate
Carrying capacity
Upward limit on size (number) of a population
Intrinsic limits
Space, resources, intra-specific competition
Extrinsic limits
Biotic: Predation, parasitism, interspecific competition
Abiotic: fires, floods, drought, etc…

9. Carrying Capacities
2013

10. Ecological Concepts -Communities
Co-existing populations of multiple species within the same habitat
Species diversity
# of species sharing a habitat and how abundant each species is
Species Richness
How many different species
Species evenness
How many individuals of each species

11. Populations - Interactions
Interspecific interactions
Detrimental (-)
Beneficial (+)
Neutral (0)
Predation
Parasitism
Commensalism
Mutualism
Competition
Keystone species
Any species whose removal from a population will cause extinction of other species

12. Niche Guilds

13. Character Displacement
Competition within a niche forces exclusion and adaptation
competition
no competition

14. Predation

15. Keystone Species

16. Ecosystems
The transfer of energy among populations of organisms with a habitat
Trophic levels
Primary producers
Fix and store energy from outside the ecosystem – plants
Consumers
Primary – herbivores
Secondary – carnivores, insectivores
Decomposers – bacteria, fungi, nematodes, protozoa, annelids

18. Energy Flow in Ecosystems