AP Bio: Friday, 12/16/11 Intro to ECOLOGY

AP Bio: Friday, 12/16/11Intro to ECOLOGYHomework:PLANTS Test on Tuesday (review Monday after school)Chapter 50 & 54 Notes due Wednesday and BIOME CHOICE for projectDo Now:What is the difference between biotic and abiotic?Define acommunitypopulationecosystemGoals for Today:Identify the realms of population, community, and ecosystems ecologyDescribe the difference between r- and K-selected species and their modes of population growthThemes of EcologyInterdependence Food webs and population interactionsEnergy flows in one direction and is transferred inefficientlyNutrients cycle: your waste = my foodHuman impacts

Population EcologyLife history strategies - based on reproductive strategies

Two extremes:

The Fast and the Furious/The Young and the Restless

Slow and Steady

Survivorship CurvesFraction of Survivors

Max. Life Span

Population GrowthDetermined byBirth rateDeath rateImmigrationEmigration

Factors Influencing Population Growth:Density-dependent Depends on population density (has a greater effect on higher-density populations)Ex:

Density-independent Does not depend on population density (kills same proportion regardless)Ex: weather conditions, toxic pollutants, amount of sunlight

Two Models for Population Growth:(1) Exponential GrowthOccurs whenUnlimited foodLow levels of predationNot a lot of diseaseLack of density-dependentfactorsr-selected populations

dN/dt = rmaxN

N = population sizermax = natural rate of increase

African Elephants in Kruger National Park, South Africa

(2) Logistic GrowthCarrying Capacity (K) the maximum population size that an environment can sustainably support over timeLogistic growth occurs whenDensity-dependent factors (food, habitat, etc.) are in effectK-selectiondN/dt = rmaxN[(K-N)/K]

Make a predictionWhat kind of growth is the human population experiencing?Human Population GrowthWhat is Earths carrying capacity for humans?

AP Bio: Wednesday, 12/21/11Community EcologyHomework:Revisions on Free Response section of plant test required for anyone who has written comments even if you scored a 10!Completed Ecology notes and top 3 Biome choicesDo Now:Get back your test and look it overGoals for Today:Define and explain niche and successionDescribe relationships in community ecologyCommunity InteractionsNiche The particular way that a species uses biotic and abiotic resources in its environmentJob description includes habitat, food & water sources, etc.Species interactions can be positive, negative, or neutralExamplesCompetitionOccurs when two species have overlapping niches!ExamplesNiche partitioning via natural selectionIntroduced/Exotic Invasive SpeciesOften out-compete native speciesWhy?Result?

AP Bio: Thursday, 12/22/11Community EcologyHomework:Work on your Biome Project over break. Nothing due right when we get back so have a well-deserved vacation!Do Now:What are some adaptations of prey?Goals for Today:Explain how natural selection drives adaptations in predators and preyInterpret a food webDefine and explain successionStart your Biome project!

PredationOne organism eats anotherCan drive natural selection in bothpredator and preyPredator adaptationsPrey adaptationsCryptic colorationToxins and warning colorationMimicry

PredationPredator-prey population cycles

Food Webs Arrows follow energy flow!

Keystone Species

Ecological SuccessionThis picture shows a mountainside in NH that was clear-cut (all trees removed).How do you think this area would look in a year? In 5 years? In 50 years?

Ecological SuccessionThe changes in community composition (number and type of species) over time, after an ecological disturbancePrimary Succession when a new community is established in a lifeless area (no soil, etc.)After a glacier, volcanic eruption, new volcanic islandSecondary Succession - when an existing community is wiped out, but soil and some life remainsAfter forest fire, or land cleared for farmlandColonization of the disturbed area often shows a predictable sequence of steps, with predictable speciesPioneer species first ones to colonizeClimax species those that are dominant in the stable, end-stage, fully recovered community

Ecological Succession

AP Bio: Tuesday, 1/3/12 Review of POPULATION & COMMUNITY ECOLOGYHomework:Work on Biome ProjectDo Now: On an index cardWhat is one thing you learned in our ecology unit before break?How is your biome project going? What have you accomplished so far? Where are you getting stuck? What are your next steps? Do you need my help or advice on anything?Goal for Today:Apply knowledge of population and community ecology to AP Biology exam questions.AP Bio: Wednesday, 1/4/12Energy Flow in EcosystemsHomework:Work on Biome ProjectDo Now:Sit with your partner from yesterdayWell correct your practice quizzes togetherGoal for Today:Define and explain trophic levels and primary productivityExplain energy transfer through ecosystems, and relate this to biological magnificationFood Webs (Review) and Trophic LevelsDo Now: Complete the worksheet

AP Bio: Thursday, 1/5/12Energy Flow and Nutrient CyclesHomework:Lab 12 Pre-Lab for Part A (read all background info, answer questions on pages 1-2)Do Now:Take out your notebooksGet ready to answer the question on the next slideGoal for Today:Define and explain trophic levels and primary productivityExplain energy transfer through ecosystems, and relate this to biological magnificationExplain how water, carbon, and nitrogen cycle through ecosystemsExplain the effects of clear-cutting and run-off on forest and aquatic ecosystemsApply all of this to your biome project!

Chemical cycling vs. Energy flow Whats the difference? What do you notice?

ENERGY FLOW

Energy flow: Open system!Input: Solar energyOutput: HeatEnergy flows in one direction (producer consumer )Energy is lost as heat during every energy transfer!

The 10% rule only about 10% of the energy from one level gets transferred to the next trophic level.

The rest is used for cell respiration and/or lost as heat.

If the seawater is contaminated with a chemical toxin, which organism will show the highest levels of the toxin in its tissues?

Biological MagnificationThe increase in the concentration of a toxin within organisms tissues as you move up a food chain

Why does this happen?

What determines how much energy is captured and flows through an ecosystem?Primary ProductivityTotal PP (also known as gross primary productivity) = the total amount of light energy that is converted into chemical energy by photosynthesis in a given amt. of time.

Net PP = Gross PP minus the energy used by producers for cell respirationThis is the amount available to the rest of the food webNPP = GPP RespirationFactors determining primary productivity:Amount of sunlightAmount of waterTemperatureAmount of nutrients

NUTRIENT CYCLING

Closed system no inputs or outputs!Chemical nutrients cycle between abiotic sources (air, water, soil) and biotic sources (producers, consumers, decomposers)

Water Cycle

What powers it?

Carbon Cycle

Water is both a reactant and a product in the carbon cycle. Explain!

In what form is the carbon at this point in the cycle?

Important Macro-Nutrients for Plants:Nitrogen (N)Phosphorus (P)Potassium (K)

NP50

Nitrogen Cycle

Who are the key players in cycling nitrogen?

AP Bio: Friday, 1/6/12Lab 12A: DO and Water TemperaturePlug in the hot plate and start heating some water!!Homework:Biome Project due Tuesday be ready to share it with the classDo Now:Take out your Lab 12 packet to review the pre-labGoals for Today: You will be able toDefine DO and explain the factors that influence itFollow a procedure for measuring DO in water samplesTest a hypothesis about the effects of water temperature on DO concentration