AP Bio: Monday, 12.20.10 Unit 7: Ecology. Homework: Decide which biome you will do for your project Finish reading and taking notes on Chapter 54 Do Now: How do you define ecology ? Goals for Today: Describe the differences between the way that energy and nutrients move through ecosystems - PowerPoint PPT Presentation
Root nodules on legumes: formed by Rhizobium bacteria
AP Bio: Monday, 12.20.10Unit 7: EcologyHomework:Decide which biome you will do for your projectFinish reading and taking notes on Chapter 54Do Now:How do you define ecology?Goals for Today:Describe the differences between the way that energy and nutrients move through ecosystemsDefine and explain primary productivity and explain what factors influence itAgenda:Introduce Biome ProjectLecture: Intro to EcologyEcology - The study of interactions between organisms and their environmentother organisms abiotic factors
Big Themes of this Unit:Energy flow in one direction, and inefficient transferNutrient cycling (my waste = your food)Interdependence (within populations, and between species [food webs])Human impacts on ecosystems
Ecosystems EcologyEcosystem all the organisms and abiotic factors in a given areaEx:a hardwood forest ecosystem in central MAa freshwater pondEcosystem components interact through transfers of energy and nutrients.What do the following images show concerningenergy flow vs. nutrient cycles?
Energy Flow:One-way series of energy transfers:Solar energy
Chemical energy stored in organisms
Heat energyInefficient transfer at each step (1% - 20% transferred; the rest is used for metabolism & ultimately lost as heat)Energy cant be recaptured or used again once its lost as heatNutrient Cycling:Cyclic transfer of nutrients between biotic and abiotic componentsSoil/waterProducers
DecomposersConsumersAll atoms are continually recycled no net inputs or outputs in the biosphere
Energy Transfer is Inefficient
1% of solar energy captured by primary producers~ 10% of energy transfer between each trophic levelFoundation of the Food Web: Primary ProductivityPP = the amount of light energy converted to chemical energy (organic compounds i.e. sugars) by producers (autotrophs) in a given time periodCan be thought of asThe amount of photosynthesis doneThe amount of carbon fixedGross PP = total amountNet PP = total amount minus the energy used for cell respiration by the producers themselvesNPP = GPP Resp.Global NPP: What influences it?
Primary Productivity inAquatic EcosystemsLimited by availability ofLightNutrientsHow do we measure aquatic PP? (this weeks lab)6C02 + 6H20 C6H12O6 + 602Oxygen produced during photosynthesis dissolves in water DO2Measuring DO gives a measure of PPAP Bio: Tuesday, 12.21.10Nutrient CyclesHomework:Work on your biome projectDo Now:What powers the water cycle?Goals for Today:Explain how water, carbon, and nitrogen cycle through ecosystemsAgenda:Hand back testsLecture/Discussion of Notes: Nutrient CyclesPractice MCQsNutrient CyclesWater Cycle:Carbon Cycle:
Nutrient CyclesNitrogen Cycle:
How Does Nutrient Availability Affect Aquatic Ecosystems?
How Does Nutrient Availability Affect Aquatic Ecosystems?Eutrophication process in which aquatic ecosystems become (overly) full of nutrients like N, K, and PAllows algae to grow (too) prolifically algae bloomAlgae blocks sunlight for other plantsAlgae die and decomposer bacteria eat them and flourishBacteria use up all the DO2None left for fish and other organisms they die ocean dead zones
Interactions between Organisms and Nutrients: The Hubbard Brook ExperimentCut down all trees, measure nutrients in run-off water
Conclusions?Trees help hold nutrients in the ecosystem!
Interactions between Organisms and Nutrients: The Hubbard Brook ExperimentAP Bio: Wednesday, 12.22.10Population & Community EcologyHomework:Work on your biome projectDo Now:Get a laptopGoals for Today:Identify the key characteristics and major species of your biome or ecosystemApply ecological concepts to a particular biome or ecosystemDescribe the factors that influence population growth in a speciesIdentify types of interactions between species in a communityAgenda:Period 1: Work on Biome ProjectPeriod 2: Lecture Population & Community EcologyPopulation EcologyLife history strategies - based on reproductive strategies
The Fast and the Furious/Slow and SteadyThe Young and the Restless
Survivorship CurvesFraction of Survivors
Max. Life Span
Population Growth:Determined by birth rate and death rateDensity-dependent factors limit population growthResources (food, nutrients, light, habitat/territory)DiseaseAggressive behavior
Density-independent populations birth and death rates dont change with increasing population size
Two Models for Population GrowthExponentialGrowth
dN/dt = rN
r-selected populations (r = growth rate; this determines pop. growth)
(2) Logistic Growth
dN/dt = rN([K-N]/K
K = Carrying Capacity - The maximum population size that an ecosystem can sustainably support over time
K-selected populations carrying capacity determines population size
Human Population GrowthExponential or logistic?What is Earths carrying capacity for humans?
Community Ecology(interactions between species)Niche The particular role that a species plays in its communityFood, predators, micro-habitat, active time of day
Interactions between species can be positive, neutral, or negative+/++/n+/--/-
Competition - Species compete for food, water, light, habitatOccurs when niches overlapIntroduced / Exotic Invasive Species often outcompete native species
AP Bio: Thursday, 12.23.10Ecological SuccessionHomework:Work on your biome projectHave a great vacation!
Do Now:If the clear-cut area shown above were left alone (no more trees cut) for 20 years, how do you think the community of species would change over time?Why?What do you think the phrase ecological succession means?
AP Bio: Thursday, 12.23.10Ecological SuccessionGoal for Today:Predict how and why ecological communities change after a disturbance
Agenda:Partner Practice-Quiz: Free Response QuestionGrade question and discuss successionFinish up lecture from yesterday
(Sorry, we couldnt get computers for today )
AP Bio: Monday, 1.3.11Welcome Back & Happy New Year!Homework: Lab 12 Pre-Lab (#1-5)Do Now: (please write this in your notebook)Describe one cool thing you did or learned over the break.Do you want to present your biome project to the whole class?What is primary productivity? (check your notes for a reminder)Goals for Today:Define and explain primary productivityIdentify key characteristics of major biomesFoundation of the Food Web: Primary ProductivityPP = the amount of light energy converted to chemical energy (organic compounds i.e. sugars) by producers (autotrophs) in a given time periodCan be thought of asThe amount of photosynthesis doneThe amount of carbon fixedGross PP = total amountNet PP = total amount minus the energy used for cell respiration by the producers themselvesNPP = GPP Resp.Global NPP: What influences it?
Primary Productivity inAquatic EcosystemsLimited by availability ofLightNutrientsHow do we measure aquatic PP? (this weeks lab)6C02 + 6H20 C6H12O6 + 602Oxygen produced during photosynthesis dissolves in water DO2Measuring DO gives a measure of PPAP Bio: Monday, 1.3.11Biome ProjectsHomework: Lab 12 Pre-Lab (#1-5)
Goals for Today:Define and explain primary productivityIdentify key characteristics of major biomes
AP Bio: Tuesday, 1.4.11Dissolved Oxygen LabHomework: Lab 12 Part A Graph and analysis
Do Now:Take out Lab 12
Goals for Today:Experimentally determine how temperature affects the dissolved oxygen content of water
Agenda: Lab!AP Bio: Tuesday, 1.4.11Lab 12 Part B: Primary ProductivityHomework: NoneDo Now:Take out Lab 12 and turn to page 8Goals for Today:Set up an experiment to determine how water depth (aka % light) affects primary productivity of aquatic algaeAgenda:Review Lab 12 Part ABiome PresentationPre-Lab for Part BSet up Part BBiome browsing
PredationOne species eats anotherPredator adaptationsPrey adaptationsCryptic colorationToxins and warning colorationMimicry
Predator-prey population cycles