Agenda 9/4 Intro to ecology lecture Food webs and interactions activity Homework: ‘Populations’ Video and Notes ‘Exponential Growth’ Video and Notes Chp 53 Notes due tomorrow *Bring green peppers (or other color) for class tomorrow! 

Intro to Ecology

Why is studying ecology important? https://www.youtube.com/watch?v=RLmKfXwWQtE How does this relate to other disciplines? How does this relate to other biology topics?

Ecology Defined Ecology is the study of organisms and their interactions with the environment What do we observe in the video clip?

Types of Ecology Organismal ecology is the study of physiology and behavior interacting with environmental challenges Population ecology studies the factors impacting the number of individuals of a species in an area Community ecology is the study of how organisms interact with each other and the environment Ecosystem ecology studies the energy flow and chemical cycling in a given area

What interactions do you see? (or infer)

Abiotic and Biotic Interactions The purple arrows indicate the heat energy released at each stage. The First Law of Thermodynamics states that energy (or matter) cannot be created or destroyed, but can only change forms. Students know it’s restatement as “The Law of Conservation of Energy” and/or “The Law of Conservation of Matter”. Point out to students that each and every time energy or matter “changes form” energy is invariably conserved but the internal energy of a closed system changes as heat and work are transferred in or out of it. (Closed systems are rare in biology!) http://www.sci.uidaho.edu/scripter/geog100/lect/16-ecosystems-biomes/ecosystems-files/ecosystems.htm

Abiotic and Biotic Interactions Big Idea 2: Biological systems utilize free energy and molecular building blocks to grow, to reproduce & to maintain dynamic homeostasis. The red arrows show the cycling of matter as components are broken down and reassembled into other things. The cycle continues through an ecosystem and throughout the biosphere. The yellow arrows indicate the energy that is not being lost in each transformation, but rather that it is being converted to a lower quality of energy that we refer to as “heat” (which directly contributes to an increase in entropy since warm bits of matter have molecules that are moving faster, thus are more disordered, thus have higher entropy). The second law of thermodynamics.

What abiotic factors affect the biotic factors? -heat -soil -rocks -sun -air -water? -mountain nutrients

Macro vs. Microclimate Macroclimate: patterns of the global, regional, and landscape level Microclimate: consists of very fine patterns on a small scale Ex: the ecosystem underneath a log Ex: A section of skin What organisms would be found there? Ecosystems exists on many different scales!

80 60 40 20 Limpet Sea urchin Both limpets and urchins removed Only urchins removed Only limpets removed August 1982 February 1983 1984 Control (both urchins and limpets present) Seaweed cover (%) Removing both limpets and urchins or removing only urchins increased seaweed cover dramatically. Almost no seaweed grew in areas where both urchins and limpets were present, or where only limpets were removed. 100 Seaweed cover (%) Spend a bit of time on this slide. When faced with experimental data, students regularly confuse the “what happened” (results) with the “why it happened” (conclusion) Results: Fletcher observed a large difference in seaweed growth between areas with and without sea urchins. Conclusion: Removing both limpets and urchins resulted in the greatest increase of seaweed cover, indicating that both species have some influence on seaweed distribution. But since removing only urchins greatly increased seaweed growth while removing only limpets had little effect, Fletcher concluded that sea urchins have a much greater effect than limpets in limiting seaweed distribution. Practice this at every opportunity!

Ecology: The Big Picture Biological systems interact, and these systems and their interactions possess complex properties. Abiotic and biotic factors influence populations, communities, ecosystems, and the biosphere. Over time species have adapted, died, or moved to more suitable environments.

Exit Ticket Sketch a graph (make up the data) that would represent abiotic and biotic factors interacting in an ecosystem