Presentation on theme: "Pretest Unit 3: Population Ecology"— Presentation transcript:
1 Pretest Unit 3: Population Ecology What is a population and how do ecologists study itExplain the difference between a niche and habitatExplain the predator/prey relationship and carrying capacity on the graph.Explain why animals fightExplain how certain factors limit a populationExplain animal extinction and how it affects an areaWhat is succession and how does it occur?
3 Species, Populations, Community, and sampling LT: Organisms occupy a specific area
4 Species and CommunityFact 18 A species is a group of organisms that are physically similar and can mate with each other and produce offspring that can also mate and reproduce.Fact 15 A community is all the different populations that live together in an area.
5 populationsFact 16 A population is all the members of one species in a particular area.the entire group of items or individuals being studiedPopulations change over timeThere are many factors that influence a populationNaturalUnnaturalFact 38 Population density (number in an area) has a great impact on ecosystemsPopulation dynamics is the study of how the characteristics of the population change in response to changes in the environmental conditions
6 Bellwork` 10/30 What are three things we learned about yesterday? You must have a sentence about each one
7 Sampling Sample: a part of the population being studied Sampling populations gives an idea ofSize- how manyDensity- how many in a specific areaDispersion- how close or far away from each otherLocation- where species are locatedA representative sample of the population is needed in order to make a valid inference, or an accurate prediction based on dataSurvey: a method of gathering information about a specific group of items or individuals
8 Example 1: A 7th grade homeroom was surveyed to determine how many texts students at Olean Intermediate Middle School send each day.What is the population?All students in the schoolWhat is the sample?Students in the seventh grade homeroom that was surveyedBiased or unbiased?Biased. One class of 7th graders does not accurately represent all students in the school.
9 Example 2: To track migration patterns of a particular species of bird, scientists randomly tag, release, and track 50 birds of that species.What is the population?The species of bird being studiedWhat is the sample?The 50 birds that the scientists taggedTagged birds are specially marked birds that are tracked. Scientists use the data on these birds to make generalizations about an entire bird species.Biased or unbiased?Unbiased. The birds tagged were randomly selected.
10 Four factors of population change Natality - births within the populationMortality - deaths within the populationImmigration =-arrival of individuals from outside the populationEmigration =-departure of individuals from the populationGrowth rate formula -(Crude birth rate + immigration rate) - (Crude death rate + emigration rate) - Growth rate
11 Population changes affect communities As population in one species declines, other species may appearHuman development now displaces other species and threatens biodiversity
12 Species, Population, Community, Sampling. Picture MappingToday you will create a visual representation about the topics we discussedOnly picturesNo wordsDetailed enough for a random person to understand the topicsSpecies, Population, Community, Sampling.
13 Habitat and Niche Notes LT: Organisms occupy a specific area
14 Habitat - A habitat is the specific environment that provides the things an organism needs to live, grow and reproduce.Includes living and nonliving elementsScale-dependent: from square meters to mileseach organism thrives in certain habitats, but not in others (habitat use)Habitat selection - the process by which organisms actively select habitats in which to liveAvailability and quality of habitat are crucial to an organism’s well- being
15 Niche A niche is the role an organism plays in its habitat, or how it makes a living. total way of life or role of a species in an ecosystemHabitat use, food selection, role in energy and nutrient flowInteractions with other individualsSpecialists - species with narrow niches and very specific requirementsExtremely good at what they do, but vulnerable to changeGeneralists = species with broad niches that can use a wide array of habitats and resourcesAble to live in many different places
18 Organisms interact in different ways Predator prey interactionsA predator is the organism that does the killing in a predation interaction.Prey is an organism that is killed and eaten by another organism.CompetitionCompetition is the struggle between organisms to survive as they attempt to use the same limited resource.CooperationCooperation is the process of groups of organisms working or acting together for their common/mutual benefit
19 A concept map of what effects the size of a population. Population SizeA concept map of what effects the size of a population.population growsDecrease in predatorsplenty of foodfood shortagePredatorsFoodincrease in predatorsPOPULATION SIZEpopulation fallsovercrowdingDiseaseincreased aggression / competition for resources
20 Animals that eat other animals Populations of animals are often limited by the amount of food.animals that eat other animals are calledpredatorsanimals that predators eat are calledprey
21 Predator and prey aadaptations Predators are adapted to catching and consuming their prey.Prey have adaptations to detect and prevent being eaten by predators.
22 Prey Adaptations – General Prey have adaptations to detect and prevent being eaten by predators.mimicryvenomous coral snakescarlet kingsnakespeed & keen sensescamouflagewarning colors & patterns
23 Predator Adaptations – General Predators have adaptations to catch and consume their prey.birds of prey have keen eyesight and sharp beaks and talonscamouflage allows predators to blend in with their surroundingsvenomous snakes have poisonous venom to subdue their preykingsnakes are immune to the venom of venomous snakestreefrogs have special pads on their feet so they can cling to vertical surfaces
24 Predator–prey graph There are always more prey than predators. The prey always increases before the predators do.To do: Write down how you could tell which line is the predator and which is the prey on a graph. Explain why the predator increases after the prey.
25 Predator–prey graphThis population data comes from fur trapping records.How are the populations linked?
26 estimated population size (thousands) Predator–prey graphHow does the lynx population depend on the number of snowshoe hares?Take a closerlook at this partof the graph.150snowshoeharelynx100estimated population size (thousands)50180018201840186018801900time (year)
27 Predator–prey graph section Why does the peak for the lynx population always come after the peak for the number of snowshoe hares?150snowshoeharelynxFor the populationsto survive, there will always be more hares than lynxes.100estimated population size (thousands)501850185518601865time (year)
28 predator population decreases predator population increases Predator–prey cyclePredator and prey population sizes follow a cycle.What happens if the prey population increases?normal prey populationprey populationincreasesprey populationincreasespredator population decreasesas less foodpredator population increasesas more foodprey population decreasesbecause of more predators
29 predator population decreases predator population increases Predator–prey cyclePredator and prey population sizes follow a cycle.What happens if the prey population decreases?normal prey populationprey populationdecreasesprey populationdecreasespredator population decreasesas less foodpredator population increasesas more foodprey population increasesbecause of less predators
30 PREDATIONis when an individual of one species (predator) eats all or most of an individual of another species (prey).An everyday occurrence in nature.
31 Bellwork 11/10 Explain what a population is Explain predator prey relationships (be sure to talk about the graph)
32 Populations change over time: Limiting Factors in an Ecosystem Define Limiting factors. Discuss scientific nomenclature. The GTF is native to Florida and the Southeastern U.S.
33 Limiting Factors Environmental factors (either biotic or abiotic) that prevent a population from increasingReview biotic and abiotic if necessary.
34 basic need of all organisms to obtain energy from the environment Availability of Foodbasic need of all organisms to obtain energy from the environmentIf food is not available, organisms may not reproduce and/or may starveWaterThe right quantity and quality of water is a basic need of all organismsShelterA basic need of all organisms to find a suitable place to take refuge from the weather, to hide from predators, to sleep, to raise young, etc.Shelter may be biotic (like trees), abiotic (like rocks), and/or man-made (like houses)To return to title page click on the word return.
35 SpaceA basic need of all organisms to have a certain amount of spaceMust be large enough to meet organism’s basic requirements such as finding food, water, shelter, mates, etc.PredationAn organism preys on and consumes animalsDiseaseViral, bacterial, and fungal infections and infected wound sites may negatively impact organismsHabitat DestructionLoss of habitat through climate change, urbanization, and other factors
36 Populations change over time: Carrying Capacity
37 Bellwork 11/12/14 Explain what a limiting factor is Give 4 examples of limiting factorsExplain how limiting factors effect animal populations.
38 Carrying CapacityCarrying capacity is the largest population that an area can supportMaintaining a balancehttps://www.youtube.com/watch?v=QI2ixJeIxEU
39 Carrying CapacityCarrying capacity is determined by limiting factors (both abiotic and biotic)Limiting factors can include: number of predators, amount of rain, temperature, amount of food, and disease.These factors are based onLocationTimeShort term ~ seasonal changesLong-term ~global changes in factors such as climateTechnology
40 Bellwork 11/13/14 What is carrying capacity? How does carrying capacity effect a population?
41 Populations change over time: Ecologic Succession Learning Target: I will be able to explain how populations in an area take over an environmentSuccession is the gradual process by which ecosystems change and develop over timeThe change in an ecosystem that happens when one community replaces another as a result of changing biotic and abiotic factors
42 Ecological Succession: Primary The establishment of a community in an area of exposed rock that does not have topsoil is called Primary Succession.It occurs very slowly at first
43 Ecological Succession: Primary The first organisms to arrive are usually lichens or mosses, which are called pioneer species.They secrete acids that can break down rockTheir dead, decaying organic materials, along with bits of sediment from the rock make up soil.
44 Ecological Succession: Primary Small weedy plants and other organisms become established.As these organisms die, additional soil is created
45 Ecological Succession: Primary Seeds brought in by animals, water and wind begin to grow in the soil.Eventually enough soil is present for shrubs and trees to grow.
46 Ecological Succession: Primary The stable, mature community that eventually develops from bare rock is called a climax community.
47 Ecological Succession: Secondary Disturbances (fire, flood, windstorms) can disrupt a community.After a disturbance, new species of plants and animals might occupy the habitat.
48 Ecological Succession: Secondary Pioneer species in secondary succession are usually plants that begin to grow in the disturbed area.This is much faster than primary succession
49 Ecological Succession: End point? Cannot be predictedDifferent rates of growth & human involvement make it impossible to know if a true climax community has been reached.
51 Conservation BiologyConservation biology is the study of how to protect biodiversity.
52 Endangered, Threatened, and Extinct Species A threatened species is a species that could become endangered in the near future. An endangered species are species that are in danger of becoming extinct in the near future Extinction is the disappearance of all members of a species from Earth
54 If a habitat is destroyed or disrupted, the native species might have to relocate or they will die. Destruction of habitat - such as the clearing of tropical rainforests, has a direct impact on global biodiversity.Disruption of habitat - the declining population of one species can affect an entire ecosystem.