Ecology Cram Session
Ch 42-46
Ecology
Study of the interactions of organisms within their
environment
Introductory Vocabulary
Hopefully you know these already…
Is this a population, a community or an ecosystem?
What are some biotic factors? What are some abiotic factors?
Properties of Populations
1. Size – the total number of individuals in a population
2. Density – number of individuals per unit area/volume; sampling techniques like mark and recapture
3. Dispersion – pattern of spacing of individuals within the area the population inhabits; 3 kinds
What are examples of these?
Schools of fish, trees, humans
Nesting birds, territorial animals
Trees in a tropical rain forest
Which one is most common and which one is the most least common?
** Most common
** Least common
Properties of Populations Cont.4. Survivorship – shows size and
composition of a population; 3 types
1. Shows organisms with low death rates in young and middle, and high death rates in old age (humans)2. Death rate is constant over life span (hydra, reptiles, rodents)3. Very high death rate among young and declining after surviving to a certain age (fish, invertebrates with 1000’s of eggs)
Properties of Populations Cont.
5. Age Structure – diagrams show the relative numbers of individuals at each age
Exponential Growth• Humans have had
this for over 300 years
• No predation, parasitism or competition
• Has an environment with unlimited resources
Eventually…
• There is a limit to the number of individuals that can occupy one area at a particular time – this is called carrying capacity
• This capacity can change as the environment conditions change
What kind of growth is this?
LOGISTIC GROWTH
Limiting Factors• Those factors that limit population growth
• 2 categories
1. Density Dependent – increase directly as pop. Density increases; include competition for food, buildup of wastes, predation, and disease
2. Density Independent – unrelated to pop. Density; include earthquakes, storms, fires and floods
Chapter 45
• Population Interactions
Competition
• Competition (intraspecific vs. interspecific)
• Predation
• Mutualism
• Commensalism
• Parasitism
• Producers vs. consumers vs. decomposers
• Herbivores vs. carnivores vs. omnivores vs. detritivore
Types of mimicry/coloration
• Aposematic coloration – very bright coloration used as warnings
• Batesian mimicry – one harmless animal mimics the coloration of one that is poisonous
• Mullerian mimicry – two or more poisonous species resemble each other & gain an advantage in their combined numbers
What is this called?
Chapter 53
9 Biomes1. Marine
2. Tropical Rain Forest
3. Desert
4. Temperate Grassland
5. Temperate Rain Forest
6. Temperate Deciduous Forest
7. Conifer Forest – Taiga
8. Tundra
9. Chaparral
Chapter 46
Understand Global Warming & Greenhouse Effect