1. Ecology

2. Study of relationships between organisms and their environments.
WHAT IS ECOLOGY?
Study of relationships between organisms and their environments.
Biotic factors: all living parts of the environm.
Abiotic factors: nonliving parts of the environm.
(i.e. temperature, soil, light, moisture)
What do you think about when I say ecology? Recycling? Acid rain?

3. Biosphere Biome Ecosystem Community Population Organism
largest
Biome
Ecosystem
Levels of Ecological
Organization
Community
Just like with classification, ecology is hierarchal. Each level builds on itself and they fit together like nesting boxes.
Population
smallest
Organism

4. 1. Biosphere: Earth (all ecosystems)
2. Biome: ecosystems with similar life and climate ex.: tropical rainforests, tundra
3. Ecosystem: Smallest group containing both biotic and abiotic factors
4. Community: Group of different populations in an area (No abiotic factors)
5. Population: a group of organisms of same species
6. Organism: an individual.
Lets review. Organisms make up populations, populations make up communities, communities and abiotic factors make up ecosystems, and all of the ecosystems make up the biosphere. From one to many and each depending on the other.

5. Habitat vs. Niche Niche - the role a species plays in a community
Habitat- the place where an organism lives
Limiting factor- biotic or abiotic factors that limits where an organism can survive
Ex.: amount of water available, food, space, shelter
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

6. Community Relationships
1. Competition for resources: food, shelter, water, etc. 2. Predation predator kill prey for food 3. Symbiosis different species living closely together
How do they trap the sun’s energy? Through what process? What is that process similar to in animal cells?

7. - + Types of Symbiosis: 1. Commensalism 2. Parasitism 3. Mutualism
Type of relationship
Species harmed
Species benefits
Species neutral
Commensalism +
Parasitism -
Mutualism
Cleaning shrimp

8. Commensalism- one species benefits, the other is neither harmed nor helped Ex. orchids on a tree
Epiphytes: A plant, such as a tropical orchid or a bromeliad, that grows on another plant upon which it depends for mechanical support but not for nutrients. Also called xerophyte, air plant.

9. one species benefits (parasite) and the other is harmed (host)
Parasitism-
one species benefits (parasite) and the other is harmed (host)
Ex.: fleas, mosquitos, etc..
Note: parasites want to keep host alive! (why?)

10. Mutualism- both species benefit each other Ex
Mutualism- both species benefit each other Ex. cleaning birds and alligators, lichen
The Egyptian plover takes insects from the backs of buffaloes, giraffes and rhinos. The plover has also been observed taking leeches from the open mouths of crocodiles! In this association the plover receives a supply of food and the other animal rids itself of unwelcome pests

11. The food web: trophic levels
Producer = autotrophs - Make own food -
Consumer = heterotrophs - Consume food
-Can be:
primary -> herbivores (eat plants)
secondary,tertiary -> carnivores (eat meat) or omnivores (eat meat and plants)
Always bottom of food chain
Trophic Level: Each link in a food chain;
A feeding step in transfer of energy in ecosystem.
How do they trap the sun’s energy? Through what process? What is that process similar to in animal cells?

12. Other feeding categories: Scavengers: eat decaying animals
Ex: vultures
Detritivores: eat pieces of organic matter in soil
Ex: worms, crabs
decomposers: absorb (do not “eat”) nutrients from decaying organic matter
Ex: fungi
Scavengers are a type of carnivore that eat dead animals, or carrion. Vultures, hyenas, crabs, deep sea fish-talk about distance from the sun and must eat the dead things that sink to the bottom, bottom feeders

13. Trophic Levels flow of energy
0.1% Tertiary consumers- top carnivores, omnivores
1% Secondary consumers-small carnivores
10% Primary consumers- Herbivores
100% Producers- Autotrophs

14. Only 10% of energy and biomass are transferred from bottom of food pyramid to the top!
*Biomass= amount of organic matter in a group of organisms in a habitat.
As you move up a food chain, both available energy and biomass decrease.
Energy is transferred upwards but is diminished with each transfer.

17. Trophic Levels
Food chain- linear model of energy flow **Arrow points from food to eater!

18. Food web- network of food chains

19. Food chain Food web
Linear group of food chains

22. -Cycles of Matter through biotic and abiotic factors:
Nutrient Cycles
-Cycles of Matter through biotic and abiotic factors:
1. Water cycle
2. Carbon cycle
3. Nitrogen cycle

23. Water cycle- Evaporation,transpiration, condensation,precipitation

24. Carbon cycle- Photosynthesis and respiration, combustion and decomposition cycle carbon and oxygen in environment.

25. Nitrogen cycle-
Atmospheric nitrogen (N2) makes up nearly 78%-80% of air.
Organisms can not use it in that form.
Lightning and bacteria convert nitrogen into usable forms.

26. Nitrogen cycle-
Only in certain bacteria and industrial technologies can fix nitrogen.
Nitrogen fixation-convert atmospheric nitrogen (N2) into ammonium (NH4+) which can be used to make organic compounds like amino acids.
N2 NH4+

27. Nitrogen-fixing bacteria: live in symbiotic relationship with plants of the legume family (e.g., soybeans, clover, peanuts).

28. Nitrogen cycle-
Some nitrogen-fixing bacteria live free in the soil.
Nitrogen-fixing cyanobacteria are essential to maintaining the fertility of semi-aquatic environments like rice paddies.

30. Nitrogen Cycle Atmospheric nitrogen Lightning
Denitrification by bacteria
Animals
Nitrogen fixing bacteria
Plants
Decomposers
Nitrification by bacteria
Nitrites
Nitrates
Ammonium

31. Pollution in food chains-
While energy decreases as it moves up the food chain, toxins increase in potency!!
This is called biological magnification
Ex: DDT & Bald Eagles

32. Bio NOTES: Succession and Population Ecology
Succession - a series of predictable changes that occurs
in a community over time
Two types:
1. primary succession
2. secondary succession
Terms:
pioneer species – the first organisms that live in a previously
uninhabited area
climax community – a stable, mature community that undergoes
little or no change
limiting factors – environmental factors that affect an organism’s
ability to survive (food, predators, space)
Each biome on Earth has a different type of climax community
- grasslands - rainforest

33. Primary Succession Secondary Succession occurs when a disturbance
of some kind changes an
existing community without
removing the soil
occurs on surfaces where
no soil exists
the colonization of new sites
by communities of organisms
called pioneer species
takes less time than primary
succession because soil is
already present
disturbances include wildfires,
storms, deforestation, farming
rocks
 lichens
 mosses 
 grasses, shrubs
 trees
soil
 grasses, shrubs
 trees

34. Population growth = an increase in the size of a population over time
 birthrate greater than death rate  population grows
 birthrate equals death rate  population stays the same
 death rate greater than birthrate  population shrinks
Under ideal conditions with unlimited resources, a
population will grow exponentially
exponential growth = as a population
gets larger, it also grows faster
Factors that change population size:
immigration – movement of individuals into a population from
another population
births – causes an increase in population size
emigration – movement of individuals out of a population and
into another population
deaths – causes a decrease in population size

35. Population Growth Curves
“J” curve
“S” curve
carrying
capacity
population growth when
conditions not favorable
limited resources
population growth under
ideal conditions
unlimited resources
as resources become less
available, the growth of the
population slows or stops
population grows rapidly,
exponentially
individuals in population
reproduce at a constant rate
reaches carrying capacity
- the number of organisms that
an environment can support

36. Limiting factor = the factor that has the greatest effect in
keeping down the population of an organism
Two types:
density-dependent
density-independent
Density-dependent limiting factors
- affected by the number of individuals in a given area
competition and availability of food, water and space
predation
parasitism and disease
Density-independent limiting factors
- limit a population’s growth regardless of the density of the pop.
unusual weather
natural disasters
human activities
The human population is expected to reach carrying capacity between

37. Worldwide, about half of the area covered by forests has been cleared.
Human Impact on the Environment
1. Effects of Human Overpopulation:
loss of land/habitat
water and food shortage
poor sanitation
species extinction
poverty
emerging disease
2. deforestation – loss of forests
- cause soil erosion, loss of habitat, and species extinction
Worldwide, about half of the area covered by forests has been cleared.
3. threaten biodiversity – the variety of organisms in an ecosystem
- an imbalance can cause extinction
4. pesticide use – using chemicals to kill and control pests
- will sometimes kill non-target species
- pollutes water sources
- causes health problems
5. bioaccumulation/biological magnification
– concentrations of a harmful substance increase
in organisms at higher trophic levels in a food web

38. Human Impact on the Environment
Global Warming
Acid Rain
the earth’s atmosphere
keeps some heat from
going out into space
acid rain = rain that has been
made acidic by certain
pollutants in the air
pollution in our atmosphere
causes too much heat to
stay on earth
changes overall temperature/
climate
raises sea level
affects health of ecosystems
pollutants = sulfur dioxide
and nitrogen oxides from
burning fossil fuels
causes health problems
damages forests and lakes
damages buildings