Population Growth

1. 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_A01.swf

2. Biogeochemical Cycles SaloniSaxena, Dabin Kim, Jenny Park

3. 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 non- leguminous plants (eg. Alnus spp.).  • - free-living anaerobic bacteria - blue-green algae (cyanobacteria)

4. 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 where the cycle starts.

5. 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

6. Citations • http://www.colorado.edu/GeolSci/courses/GEOL1070/chap04/chapter4.html • https://files.nyu.edu/pet205/public/carbon.html • http://www.kidzone.ws/water/

7. Symbiotic Relationships Kristen Vogt, Jen Stern, Joon Seo, Jenna o.

8. Symbiosis • When individuals of two or more species live in intimate, direct contact with each other.

9. Symbiotic Relationships • Mutualism: symbiosis that is beneficial to both organisms involved • Ex: Bees and flowers (take nectar & pollinate the flowers) • 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: 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

10. 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

11. 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

12. Mutualism • Mutualism: +/+ symbiosis that is beneficial to both organisms involved • Ex: Bees and flowers (take nectar & pollinate the flowers) • Ex: Oxpecker and zebra • Oxpeckerseat ticks and other parasites that live on their skin and the oxpeckers get food

13. 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

14. Links • http://www.bbc.co.uk/schools/gcsebitesize/science/add_aqa_pre_2011/foodchains/foodchains1.shtml • Audio Narration on Energy flow-http://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​

15. Ecological Succession By: Charlie Lee, Jacob Lee, and Edward Yoon

16. What is “Ecological Succession” • "Ecological succession”: the change in composition of the species within an ecological community over time.

17. 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.

18. 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.

19. 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.

20. Secondary Succession (Cont.)

21. 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 ​

22. Human Impact on the Environment By: Reed Murphy, Ken Klopf, Matt Guido Period 1-2 AP Biology

23. Problems Caused by Humans • Global Warming • Depletion of Ozone Layer • Acid Rain • Deforestation and Desertification • Algal Blooms • Eutrophication • Reduction in Species Diversity

24. Solutions

25. Helpful Links • http://coseenow.net/blog/2008/11/eutrophication-animation/ • http://environment.nationalgeographic.com/environment/global-warming/ozone-depletion-overview/ • http://www.epa.gov/acidrain/reducing/ • http://www.greenpeace.org/usa/en/campaigns/forests/solutions-to-deforestation/​