Bio171-F08-lec%207 - Biology 171 Wednesday Lecture 7:Global...

Info icon This preview shows pages 1–13. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 7: Global Warming Biology 171 Wednesday September 17, 2008 Today’s Topics: Announcements This Week in Discussion: Global Warming Text Reading: Lecture 7: 2 nd ed: Chapter 54 (1259-1261) 3 rd ed: Chapter 54 (1238-1241) Lecture 8: 2 nd ed: Chapter 53 (1214-1220) 3 rd ed: Chapter 53 (1196-1202) Bioamplification Carbon Cycle Fossil Fuels & Industrialization Greenhouse Gases Our Present Day Situation Possible Future Scenarios Difficult Choices
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
A local example of a food web: Avian botulism in Michigan Since the late 1990’s, hundreds of thousands of birds have died along the Great Lakes shorelines due to botulism poisoning.
Image of page 2
The Players: Clostridium botulinum – anaerobic, gram-negative bacterium Role in ecosystem: decomposer. Also produces the most toxic natural substance known to humans – botulinum toxin (aka Botox).
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
The Players: Anabaena spp. – photosynthetic cyanobacterium (and other Cyanobacteria and eukaryotic algae. Role in ecosystem: producer. Dense populations form large floating mats or scums.
Image of page 4
The Players: Dreissena spp. – Zebra and quagga mussels. Introduced from Europe/W. Asia in ship ballast water. First seen in Great Lakes in 1988 & 1990 respectively. Role in ecosystem: primary consumer. Filter phytoplakton and bacteria from water.
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
The Players: Neogobius melanostomus – Round goby. Introduced from Europe/W. Asia in ship ballast water. First seen in Great Lakes in 1995. Now endangered in native range. Role in ecosystem: secondary consumer. Feeds largely on zebra and quagga mussels.
Image of page 6
The Players: Gavia immer, Larus ridibundus, Mergus merganser – Common loon, ring-billed gull, common merganser – native birds. Role in ecosystem: secondary/tertiary consumer. Feed on fish.
Image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
The food web: The botulinum toxin moves up the food chain, poisoning fish and then birds. This is similar to the Bioamplification of certain toxic chemicals, such as pesticides, that concentrate at higher trophic levels. Chemicals such as DDT were ultimately banned because of the damage they did to apex predators such as falcons and eagles.
Image of page 8
Global Biogeochemical Cycles When nutrients leave one ecosystem, they enter another. The movement of ions and molecules among ecosystems links local biogeochemical cycles into one massive global system.
Image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Broader Implications of Ecosystem Nutrient & Energy Dynamics The atoms (chemical nutrients) that constitute our bodies at any one point in time were previously part of other organisms/inanimate objects and, as we respire and eventually die, they will continue to be recycled indefinitely. The metabolic energy we are presently using left the sun a few weeks-years ago in the form of photons and will shortly radiate back to space as heat. Given that our material composition and our energy are both transient, what do we, or any other living organisms, actually represent in a scientific sense?
Image of page 10
The Carbon Cycle (2 of 4 Reservoirs) Elemental Composition Of Life Forms (by mass)
Image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
A general model of Carbon Cycling. Arrows indicate the processes that move carbon between 4 primary reservoirs.
Image of page 12
Image of page 13
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern