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Unit 3 Ecology

Unit 3 Ecology. SB4. Students will assess the dependence of all organisms on one another and the flow of energy and matter within their ecosystem. a. Investigate relationships among organisms, populations, communities, ecosystems, and biomes.

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Unit 3 Ecology

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  1. Unit 3 Ecology SB4. Students will assess the dependence of all organisms on one another and the flow of energy and matter within their ecosystem. a. Investigate relationships among organisms, populations, communities, ecosystems, and biomes.

  2. LEQ1: What relationships exist among organisms, populations, communities, ecosystems, and biomes?

  3. Relationships • Ecology is the study of relationships among organisms and their environment. • Interactions between living things and their environment • Interactions among living things

  4. Relationships • Ecologists study the environments different levels of organization. • Organism • Population • Community • Ecosystem • Biome • Biosphere

  5. Relationships • An organism is an individual living thing, such as an alligator. • Species: group of similar organisms that can breed and produce fertile offspring. Organism Organism

  6. Relationships • A population is a group of the same species that lives in one area. Population Population Organism Organism

  7. Relationships • A community is a group of different species that live together in one area Community Community Population Population Organism Organism

  8. Relationships • An ecosystem includes all of the organisms as well as the climate, soil, rocks, water, and other nonliving things in a given area. Ecosystem Ecosystem Community Community Population Population Organism Organism

  9. Relationships • A biome is a major regional or global community if organisms characterized by the climate conditions and plant communities that thrive there. Biome Ecosystem Ecosystem Community Community Population Population Organism Organism

  10. Relationships Biosphere • The biosphere contains the combined portions of the planet in which all of life exists. • All biomes (land, water, air) • The entire planet Biome Ecosystem Ecosystem Community Community Population Population Organism Organism

  11. Observation Direct Survey Used for easy to spot species Indirect Survey Used for species that are difficult to spot or track Look for signs of their presence. Ecologist Study Relationships

  12. Experimentation Conducted in lab which gives researchers more control Conducted in the field which is a more accurate account of natural interactions Relationships

  13. Ecologists use data transmitted by GPS receivers worn by elephants to develop computer models of the animal’s movements. Relationships • Modeling • Allows scientists to learn about organisms or ecosystems in ways that would not be possible in a lab or natural setting • Use computer and mathematical models

  14. Biotic and Abiotic Factors • Every ecosystem includes both living and nonliving factors

  15. Biotic and Abiotic Factors • Biotic factors are living things. • Plants • Animals • Fungi • Bacteria Plants

  16. Biotic and Abiotic Factors • Abiotic factors are nonliving things • Moisture • Temperature • Wind • Sunlight • soil Sunlight Moisture

  17. Biotic and Abiotic Factors • Changing one factor is an ecosystem can affect many other factors • Biodiversity is the assortment, or variety, of living things in an ecosystem. • Rain forests have more biodiversity than other locations in the world, but are threatened by human activities

  18. keystone Biotic and Abiotic Factors • A keystone species is a species that has an unusually large effect on its ecosystem. • They form and maintain a complex web of life

  19. creation of wetland ecosystem increased waterfowl Population keystone species increased fish population nesting sites for birds Biotic and Abiotic Factors

  20. Habitat and Niche • Every organism has a habitat and a niche.

  21. Habitat and Niche • A habitat differs from a niche. • A habitat is all aspects of the area in which an organism lives • Biotic factors • Abiotic factors • Your address

  22. Habitat and Niche • An ecological niche includes all of the factors that a species needs to survive, stay healthy, and reproduce • Food • Abiotic conditions • Behavior • Your occupation

  23. Habitat and Niche • Species can share habitats but cannot occupy the same niche in the same ecosystem. • Competition occurs when two species use resources in the same way (occupy same niche) • Competitive exclusion keeps two species from occupying the same niche.

  24. Competitive exclusion has three different outcomes: One species is better suited to the niche and the other will either be pushed out or become extinct. The niche will be divided. The two species will further diverge. Habitat and Niche

  25. Madagascar South America Habitat and Niche • Ecological equivalents are species that occupy similar niches but live in different geographical regions.

  26. Community Interactions • Organisms interact as individuals and as populations

  27. Community Interactions • There are three main ways in which organisms interact: • Competition • Predation • Symbiosis • Mutualism • Commensalism • Parasitism

  28. Resource availability gives structure to a community. Competition occurs when two organisms fight for the same limited resource. Types of competition: Intraspecific Interspecific Community Interactions

  29. Community Interactions • Predation occurs when one organism captures and eats another organism. Predator Prey

  30. Community Interactions • Symbiosis is a relationship in which two species live closely. • Three types: • Mutualism • Commensalism • Parasitism

  31. Community Interactions • Mutualism: both organisms benefit

  32. Community Interactions • Commensalism: one organisms benefits, the other is unharmed. Demodicids Eyelash mites find all they need to survive in the tiny follicles of eyelashes. Magnified here 225 times, these creatures measure 0.4 mm in length and can be seen only with a microscope. Human: Our eyelashes are home to tiny mites that feast on oil secretions and dead skin. Without harming us, up to 20 mites may be living in one eyelash follicle.

  33. Community Interactions • Parasitism: one organism benefits, the other is harmed. Hornworm caterpillar The host hornworm will eventually die as its organs are consumed by wasp larvae. Braconid wasp Braconid larvae feed on their host and release themselves shortly before reaching the pupae stage of development.

  34. Endoparasites Hookworms Extoparasites Leeches Community Interactions Endoparasites • Live in tissue and organs of organism • Feed on nutrients ingested by host • Examples: tapeworms, protozoan, hookworms Extoparasites • Exterior of organism • Feed on host fluids • Example: leeches, fleas, ticks

  35. Population Density And Distribution • Each population has a density, a dispersion, and a reproductive strategy.

  36. Population Density And Distribution • Population density is the number of individuals that live in a defined area. • a measurement of the number of individuals living in a defined space. • Scientists can calculate population density.

  37. Clumped dispersion Uniform dispersion Random dispersion Population Density And Distribution • Geographic dispersion of a population shows how individuals in a population are spaced. • Population dispersion refers to how a population is spread in an area. • There are three types of dispersion: • Clumped • Uniform • Random

  38. Population Density And Distribution Clumped

  39. Population Density And Distribution Uniform

  40. Population Density And Distribution Random

  41. Population Density And Distribution • Survivorship curves help to describe the reproductive strategy of a species. • Diagram showing the number of surviving members over time from a measured set of births.

  42. Population Density And Distribution • Survivorship curves can be type I, II or III • Type I -low level of infant mortality and an older population • Common to large mammals and humans • Type II -survivorship rate is equal at all stages of life • Common to birds and reptiles • Type III -very high birth rate, very high infant mortality. • Common to invertebrates and plants

  43. Population Density And Distribution

  44. Population and Growth Patterns • Populations grow in predictable patterns

  45. Population and Growth Patterns • The size of a population is always changing. • Four factors affect the size of a population: • Immigration: • organisms coming into a ecosystem • Births • Emigration • Organisms leaving an ecosystem • Deaths

  46. Population and Growth Patterns • Population growth is based on available resources. • There are two types of growth: • Exponential • Logistic

  47. Population and Growth Patterns • Exponential growth is a rapid population increase due to an abundance of resources.

  48. Population and Growth Patterns • Logistic growth is due to a population facing limited resources. • Population will level out around carrying capacity.

  49. Population and Growth Patterns • Carrying capacity is the maximum number of individuals in a population that the environment can support. • A population crash is a dramatic decline in the size of a population over a short period of time.

  50. Population and Growth Patterns • Ecological factors limit population growth. • A limiting factor is something that keeps the size of a population down. • There are two types of limiting factors: • Density dependent • Density Independent

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