1. Semester 1: Unit 3
ECOLOGY

2. Ecology- scientific study of interactions among & between organisms & their physical environment.

3. 3.1- What is Ecology?
Ecology studies levels of organization:
*Specie- Individual organism
*Population- group of the same type of individuals that live in the same area
*Community- groups of different populations living together in a defined area
*Ecosystem- all the organisms that live together in a place with their physical environment
*Biome- a group of ecosystems that share similar climates & typical organisms
*Biosphere- entire planet

4. biotic factors- biological influences on organisms (living factors)
3.1- What is Ecology?
biotic factors- biological influences on organisms (living factors)
Examples of biological influences on a bullfrog- algae it eats as a tadpole, herons that eat bullfrogs, & other species competing for food or space.

5. 3.1- What is Ecology?
Abiotic factors- physical components of an ecosystem (nonliving factors)
a bullfrog could be affected by abiotic factors such as water availability, temperature, & humidity.

6. 3.1- What is Ecology? abiotic & biotic factors- not always clear
Ex: pond muck contains nonliving particles, mold, & decomposing plant material that is food for bacteria & fungi

8. 4.1- Climate main force in climate= solar energy from sun
Weather - day-to-day conditions of Earth’s atmosphere
Climate- year-after-year patterns of temperature & precipitation.
main force in climate= solar energy from sun
Some energy absorbed & converted into heat
Some heat is trapped in the biosphere & determines average temperature

9. 4.1- Climate

10. 4.1- Climate
Earth’s temp controlled by 3 atmospheric gases- CO2, methane, & water vapor
“greenhouse gases”- allow light to enter but trap heat- the greenhouse effect
Greenhouse gas concentrations rise, more heat trapped= Earth warms.
Without greenhouse effect, Earth would be 30°C cooler than it is today.

11. 4.1- Climate

12. 4.2- Niches & Community Interactions
Each species has its own tolerance- ability to survive & reproduce under a range of environmental circumstances.
Cannot survive past upper & lower limits

13. 4.2- Niches & Community Interactions
Habitat- place an organism lives. (address)
Niche- conditions in which a species lives & how it obtains what it needs to survive & reproduce. (job)
resource - necessity of life- water, nutrients, light, food, mates, space
Competition- organisms try to use the same limited resource in same place at same time
competitive exclusion principle- no 2 species can occupy exactly the same niche in the same habitat at the same time

14. 4.2- Niches & Community Interactions
Showing different species in different niches in same habitat Competition: winner? Loser?

15. 4.2- Niches & Community Interactions
Predation- one animal (predator) captures & feeds on another (prey)
symbiosis- relationship in which 2 species live closely together
3 types of symbiotic relationships:
mutualism- both species benefit
parasitism- 1 organism lives in/on another & harms it
commensalism- 1 organism benefits & other is not helped or harmed

16. 4.3- Succession
Ecological succession- series of predictable changes that occurs in a community over time
1-primary succession- begins in areas with no soil or life (ex- volcanic explosion)
pioneer species- 1st to colonize barren areas

17. 4.3- Succession rebuilds faster than primary
2-secondary succession- begins where soil remains
rebuilds faster than primary
ex-wildfire, hurricane, natural disturbance, or human activities- logging & farming.

18. 4.4- Biomes Biomes- consist of abiotic & biotic factors
seasonal patterns
of temp & precipitation
in a- climate diagram
Temp- line graph
Precipitation- bar graph

19. 5.1- How Populations Grow Exponential Growth:
Ideal conditions & unlimited resources, population grows exponentially
the larger a population, faster it grows
on a graph over time, a J-shaped curve

20. 5.1- How Populations Grow
Logistic Growth:
a population’s growth slows & then stops, following exponential growth.
Natural populations do not grow long exponentially; something stops growth
On a graph, curve has an S-shape

21. 5.1- How Populations Grow
Carrying capacity- maximum # of individuals that a particular environment can support.
Where dotted line intersects the y-axis = carrying capacity.

22. 5.2- Limits to Growth
limiting factor- factor that controls the growth of a population
Density-dependent limiting factors -operate strongly when population density is large.
D-D L F: competition, predation, herbivory, parasitism, disease, stress from overcrowding
Competition:
populations become crowded, individuals compete- food, water, space, sunlight, etc.
lower birthrates, increased death rates

23. 5.2- Limits to Growth Predation:
predator population affects prey population & vice- versa
Herbivore Effects:
To plants, herbivores are predators

24. 5.2- Limits to Growth Parasitism and Disease:
Parasites & disease-causing organisms feed & harm hosts- weaken, cause disease, or death
more dense host population, easier to spread
Stress From Overcrowding:
species fight if overcrowded; increase stress & weaken body’s ability to resist disease
Females neglect, kill, or eat own offspring
decrease births, increase deaths, & increase emigration

25. 5.2- Limits to Growth
2- Density-Independent limiting factors- affect all populations regardless of size & density
Density-Independent limiting factors include: Unusual weather- hurricanes, droughts, floods, & natural disasters- wildfires

26. 6.1- A Changing Landscape
Sustainable development- provides for human needs & preserves ecosystems that produce natural resources.
Goods- items that can be bought & sold
Services- processes or actions that produce goods.
ecosystem goods & services- produced by ecosystems that benefit human economy.
Healthy ecosystems provide goods & services naturally & free of charge: air, water

27. 6.2 Using Resources Wisely
Biological magnification- a
pollutant is picked up by
an organism & is not broken
down or eliminated from
its body.
pollutant collects in body tissues &
build as it moves up
trophic levels

28. 6.3 Biodiversity
Biodiversity- total of all the genetically based variation in all organisms in biosphere.
Ecosystem diversity- variety of habitats, communities, & ecological processes in the biosphere
species diversity- number of different species in the biosphere or particular area
Genetic diversity- sum total of all different forms of genetic information carried by a particular species, or all organisms on Earth.

29. 6.3 Biodiversity Humans reduce biodiversity by:
*altering natural habitats
*hunting
*introducing invasive/exotic species
*releasing pollution into food webs
*contributing to climate change
To conserve biodiversity, we must protect species, preserve habitats & ecosystems
ecological hot spot- place where large numbers of species & habitats are in immediate danger of extinction.

30. 6.3 Biodiversity
Development splits ecosystems into pieces- habitat fragmentation- leaving habitat “islands” - patch of habitat surrounded by a different habitat.
6.4 Meeting Ecological Challenges
ecological footprint- total area of functioning land & water ecosystems needed to provide the resources an individual or population uses & to absorb the wastes that it generates.

31. 6.4 Meeting Ecological Challenges
Ecology can guide humans toward a sustainable future & have a positive impact on the global environment by:
recognizing a problem in the environment
researching the problem to determine its cause
using scientific understanding to change our behavior