Population Growth

Exponential growth (r selected)

Logistic growth (k selected)

Fluctuating growth

Zero population growth (ZPG)

no net increase or decrease
Click for Helpful Animation
http://wps.pearsoncustom.com/wps/media
/objects/3014/3087289/Web_Tutorials/23_A
01.swf
Biogeochemical Cycles
Saloni Saxena, Dabin Kim, Jenny Park
Nitrogen Cycle
Limiting Nutrient - Amount of an element
necessary for plant life is in short supply
Nitrogen Fixation - Chemical conversion of N2 to
more reactive forms, e.g.
NH3 (ammonia) or NO3 - (nitrate)
Denitrification - Chemical conversion from
nitrate (NO3 -) back to N2
Carried out by:
- symbiotic bacteria (eg. Rhizobium spp.) living
in association with leguminous ( plants in the
pea family), and root-noduled nonleguminous plants (eg. Alnus spp.).
- free-living anaerobic bacteria
- blue-green algae (cyanobacteria)
Hydrologic cycle
Evaporation: when the sun heats up water in
rivers or lakes or the ocean and turns it into
vapor or steam. The water vapor or steam leaves
the river, lake or ocean and goes into the air
Condensation: Water vapor in the air gets cold
and changes back into liquid, forming clouds. This
is called condensation
Precipitation: occurs when so much water has
condensed that the air cannot hold it
anymore. The clouds get heavy and water falls
back to the earth in the form of rain, hail, sleet
or snow.
Collection: When water falls back to earth as
precipitation, it may fall back in the oceans,
lakes or rivers or it may end up on land. When it
ends up on land, it will either soak into the earth
and become part of the “ground water” that
plants and animals use to drink or it may run over
the soil and collect in the oceans, lakes or rivers
Carbon cycle
Carbon (C) enters the biosphere during photosynthesis:
CO2 + H2O ---> C6H12O6 + O2 + H2O
Carbon is returned to the biosphere in cellular respiration:
O2 +H2O + C6H12O6 ---> CO2 +H2O + energy
Citations

http://www.colorado.edu/GeolSci/courses/GEOL1070/chap04/chapter4.html

https://files.nyu.edu/pet205/public/carbon.html

http://www.kidzone.ws/water/
Symbiotic Relationships
Kristen Vogt, Jen Stern, Joon Seo, Jenna o.
Symbiosis

When individuals of two or more species live in intimate, direct contact with
each other.
Symbiotic Relationships

Mutualism: symbiosis that is beneficial to both organisms involved


Parasitism: a non-mutual symbiotic relationship in which one organism, the
parasite, derives its nourishment form another organism, its host, which is
harmed in the process


Ex: Bees and flowers (take nectar & pollinate the flowers)
Ex: tapeworms
Commensalism: an interaction between species that benefits one of the species
but neither harms nor helps the other

Ex: Burr-bearing seeds that are dispersed by clinging to the fur of certain birds do not
harm or help the birds

Competition: an interaction that occurs when individuals of different species
compete for a resource that limits their growth and survival

Neutralism: the relationship between two species that interact but do not affect
each other
Parasitism

-/+

Relationship where one animal lives off or benefits off
another, while negatively impacting its host

Internal parasite – live within the host


Heartworms, hookworms
External parasite – attaches onto the outside of the host

Leech, tick
Commensalism

Interaction between species that benefits one of the species but neither
harms nor helps the other


0/+
Example:

Burr-bearing seeds that are dispersed by clinging to the feathers of certain birds do
not harm or help the birds

Seeds or pollen on animal fur; does not harm the animal
Mutualism

Mutualism: +/+ symbiosis that is beneficial to both organisms involved

Ex: Bees and flowers (take nectar & pollinate the flowers)

Ex: Oxpecker and zebra

Oxpeckers eat ticks and other parasites that live on their skin and the oxpeckers get food
Competition: Predator- Prey Relationship

Predator- organism that eats other organisms

Prey- organism that is eaten by Predator

Competition occurs due to a limited supply of a
common resource between organisms.

Interference competition- occurs directly between 2
individuals

Exploitation competition- occurs indirectly between
individuals

Apparent competition- occurs indirectly between
individuals
Links

http://www.bbc.co.uk/schools/gcsebitesize/science/add_aqa_pre_2011/food
chains/foodchains1.shtml

Audio Narration on Energy flowhttp://wps.aw.com/bc_goodenough_boh_3/104/26722/6840962.cw/content/
index.html

Food Web information- http://www.bigelow.org/edhab/fitting_algae.html

Build a Food web game- http://www.bigelow.org/edhab/game.html
Ecological Succession
By: Charlie Lee, Jacob Lee, and Edward Yoon
What is “Ecological Succession”

"Ecological succession”: the change in composition of the species within an
ecological community over time.
Primary Succession

Primary Succession: the colonization of new sites by communities of organisms.

Occurs after a devastating event has wiped out the organisms that lived in an area, or
with the creation of a new habitat.

Occurs in newly formed volcanic islands formed or glacier moraine.
Primary Succession (Cont.)

Pioneer species such as lichen, mosses, and fungi settle in the barren lands.

Pioneer species break down resources/minerals and create soil for more
complex species to grow.
Secondary Succession

Secondary succession is more common than primary succession.

It begins in habitats where communities were entirely or partially destroyed
by some kind of damaging event or disturbance.

Such events can be floods, fire, forest clear-cutting, and insect invasions.

The already established community can be reduced or new populations can
develop in the environment.
Secondary Succession (Cont.)
Climax Community

Succession never really ends.

However, an ecosystem can become very stable

The climax community represents this stable state at the “end” of succession.

This climax community will maintain itself for a very long time

Big forces may catalyze change in a climax community

http://www.mrphome.net/mrp/succession.swf

http://www.psu.edu/dept/nkbiology/naturetrail/succession.htm
Human Impact on the
Environment
By: Reed Murphy, Ken Klopf, Matt Guido
Period 1-2 AP Biology
Problems Caused by Humans

Global Warming

Depletion of Ozone Layer

Acid Rain

Deforestation and Desertification

Algal Blooms

Eutrophication

Reduction in Species Diversity
Solutions
Problem
Solution
Global Warming
Limit use of fossil fuels, stop cutting down
forests
Depletion of Ozone Layer
Restrict use of chlorofluorocarbons
Acid Rain
Limit use of fossil fuels (SO2)
Deforestation and Desertification
Stop cutting down forests, prevent overfarming
and removal of livestock/wildlife
Eutrophication
Decrease fertilizer use, rotate crops
Algal Blooms
Decrease fertilizer use, rotate crops
Reduction in Species Diversity
Prevent habitat destruction, poaching,
overhunting, overfishing
Helpful Links

http://coseenow.net/blog/2008/11/eutrophication-animation/

http://environment.nationalgeographic.com/environment/globalwarming/ozone-depletion-overview/

http://www.epa.gov/acidrain/reducing/

http://www.greenpeace.org/usa/en/campaigns/forests/solutions-todeforestation/