1. ECOLOGY
CH. 1 & 2

2. ECOLOGY
Def: the study of how living things interact with their environment
Habitat – where an organism gets the things it needs to survive
Biotic Factors  Living
Abiotic Factors  Non-living
Levels of Organization
Organism – individual
Population – members of same species
Species – similar organisms that are capable of producing offspring that are similar to parents
Community – all the populations in an area
Ecosystem – the community plus non-living parts of the area
Biome – A large Ecosystem based on precipitation and temperature
Tundra, Taiga, Deciduous Forest, Rain Forest, Desert
Biosphere – all the ecosystems of the world

4. Studying Populations Population – number of individuals Methods
Population Density – individuals/ unit of area
How crowded it is
Methods
Direct Observation – actually seeing
Indirect Observation – seeing evidence without seeing individuals
Ex.
Sampling – average of smaller areas to estimate total population
Mark and Recapture
(# Marked X # captured 2nd time)/ # caught 2nd time with marks

5. Studying Populations Changes to population
Birth rate vs. Death rate
Immigration (in) vs. Emigration (exit)
Limiting Factors – environmental factors that prevent a population from increasing
Ex.
Carrying Capacity – the maximum number of individuals an area can support
Based on limiting factors

7. Interactions Among Populations
Niche – how an organism interacts and uses its habitat
The role or job of an organism
Adaptations – Physical characteristic or behavior that make an organism more likely to survive (better able to use habitat)
Keeps niches different from other species
Natural Selection – survival of the fittest
Forms adaptations
Competition – struggle for limited resources
Hurts both species
Can be members of same species (intraspecific) or members of different species (interspecific)

8. Interactions Among Populations
Predation – A specie hunts, kills, and eats another
Predator Adaptations:
Prey Adaptations:
Mutualism – Both species benefit (+/+)
Commensalism – One species benefit, the other is unaffected (+/0)
Parasitism – one species (parasite) lives off from another (host) causing it harm
Doesn’t usually kill host

9. Energy Flow through an Ecosystem
Food Chain  single path
Food Web  many, interconnected food chains
Trophic Levels
Producer – autotrophs
Photosynthesis
Consumer – heterotrophs
Primary consumer
Herbivores – only eat producers
Secondary Consumer –
Carnivore – only eat other consumers
Omnivore – sometimes primary, sometimes secondary
3rd level, 4th level etc.
Scavengers – carnivore that eats the already dead

10. Energy Flow through an Ecosystem
Decomposers – detritivores
Almost all energy passes here last
Exception: stored energy in fossil fuels
Energy Pyramid – shows total amount of energy in each trophic level for an ecosystem
Most energy in producers
10% is passed onto next trophic level
Each trophic level has less individuals
Not many top carnivores
Limit to number of levels in food chain

11. MATTER CYCLES Hydrologic – Water Cycle
Evaporation – liquid to gas (water vapor)
Purifies; only water goes up
Transpiration –trees/plants evaporating water
Condensation – water vapor to liquid
Clouds & fog
Precipitation
Rain, snow, sleet, hail, ice
What happens next?
Surface Run-off – ditches  streams  lakes, rivers  oceans
Aquifer – ground water
Ends up in living organisms
Evaporation – returns directly to atmosphere

12. MATTER CYCLES Carbon Cycle Found in atmosphere as Carbon Dioxide (CO2)
.03%
Linked to global warming as environmental concern
Needed by organisms to form organic compounds
Converted by plants through the process of photosynthesis
Returned to atmosphere
Respiration – breaking down carbon compounds for energy
Decomposition – dead organisms broken down by fungi/bacteria
Combustion – burning fossil fuels or plant products
Double Whammy! – Deforestation
Can’t take carbon out
Burning puts carbon in
Fossil Fuels – carbon stored deep in Earth
Past organisms
Oil, natural gas, coal

13. MATTER CYCLES Nitrogen Cycle
Found in the air as atmospheric nitrogen (N2)
78% of air; most abundant substance
Can NOT be used directly by most organisms
Nitrogen fixation – changing atmospheric nitrogen into a usable form
Needed by organisms to make proteins
Rhizobium (bacteria) or lightning
Found on root nodules in Legumes (alfalfa, clover, beans)
Atmospheric nitrogen is changed into ammonia (NH3) or nitrates (NO4)
Can be added to soil through fertilizers or decomposition of organisms
Denitrification changes nitrogen compounds back into atmospheric nitrogen by bacteria.

14. WATER CYCLE Hydrologic Cycle– Water Cycle
Evaporation – liquid to gas (water vapor)
Purifies; only water goes up
Transpiration –trees/plants evaporating water
Condensation – water vapor to liquid
Clouds & fog
Precipitation
Rain, snow, sleet, hail, ice
What happens next?
Surface Run-off – ditches  streams  lakes, rivers  oceans
Aquifer – ground water
Ends up in living organisms
Evaporation – returns directly to atmosphere

15. CARBON CYCLE Carbon Cycle Found in atmosphere as Carbon Dioxide (CO2)
.03% of air
Linked to global warming as environmental concern
Needed by organisms to form organic compounds
Converted by plants through the process of photosynthesis
Returned to atmosphere
Respiration – breaking down carbon compounds for energy
Decomposition – dead organisms broken down by fungi/bacteria
Combustion – burning fossil fuels or plant products

16. CARBON CYCLE Double Whammy! – Deforestation Can’t take carbon out
Burning puts carbon in
Fossil Fuels – carbon stored deep in Earth
Past organisms
Oil, natural gas, coal

17. NITROGEN CYCLE Nitrogen Cycle
Found in the air as atmospheric nitrogen (N2)
78% of air; most abundant substance
Can NOT be used directly by most organisms
Nitrogen fixation – changing atmospheric nitrogen into a usable form
Atmospheric Nitrogen is changed into nitrates (NO3) or ammonia (NH4)
Needed by organisms to make proteins

18. NITROGEN CYCLE Legumes or Lightning Cycle within a cycle
Legumes are plants (alfalfa, clover, beans, etc) that have bacteria called Rhizobium on their roots that turn N2 into Nitrates
Crop Rotation
Cycle within a cycle
Nitrates can be returned directly to the soil through decomposition
Can be added to soil through fertilizers or decomposition of organisms
Denitrification changes nitrogen compounds back into atmospheric nitrogen by bacteria.
Must be returned to complete cycle

19. Succession Read Section 2-5 (p. 76-78) Topics (Objectives): Key Terms:
Read Silently
Take a break after each section and ask, “what did I just read?”
Write down Topics or Objectives you should be able to accomplish after reading
Make a list of key terms and key ideas (these are the notes)
Topics (Objectives):
Know the definition of succession
Know the difference between primary and secondary succession
Know the order of change that occurs during succession
Key Terms:
Succession, pioneer species, biome

21. Succession
Def: the change of an ecosystem back to its climax community
Climax community – the natural state of an ecosystem
Based on climate (weather, temp), altitude, soil etc.
Biomes
Pioneer species – first to arrive after disturbance
Lichens, weeds
Animation
Primary – no pre-existing ecosystem
Secondary – return after disturbance
Can be human or natural disturbances.  ex: