2.1 Species and Populations

1. 2.1 Species and Populations

2. IB TESTING TIPS: • IB often asks for named examples, be sure to use specific examples and use specific names (scientific names are not required). • For example if you just say tiger this refers to 1 of 10 species versus Bengal tiger is specific to one region and one species! • For a named example of a habitat or ecosystem • be specific; The Giant Kelp Forest off the coast of Monterrey Bay California is much better than the beach • give as much detail as possible; The Sundarbans is the largest mangrove forest in Southern Bangladesh and South-eastern India.

3. What is an Ecology? • The study of the living and non-living parts that interact within an ecosystem.

4. What is an Ecosystem? • A community of interdependent organisms and the interactions with the physical environment in which they live. • It can also be defined as the abiotic and biotic factors and the interactions between them. • The interaction between organisms and the environment is the key!

5. Ecosystems Have Living and Nonliving Components • Abiotic – Non-living • Water • Air • Nutrients • Rocks • Heat • Solar energy • Biotic- Living • Any living or once living

6. Biotic or Abiotic? • River dolphin • Algae • Daylight hours • Precipitation • Moss • Soil composition • Bacteria • Mushroom • Rocks • Minerals • Mangrove trees • Swamp grass

7. Major Biotic and Abiotic Components of an Ecosystem Fig. 3-6, p. 59

8. Which factors are biotic and which are abiotic? Note: Correlation NOT causation

9. How many of these terms do you know? • Organism • Species • Population • Community • Niche • Habitat In your notebook draw a bunch of little organisms. Some of the same type of some of different types. • Label 1 individual as an organism. • Label a group of the same type of organisms (species) • Circle: individuals of the same species (Population) • Draw interactions between the populations (Community)

10. Naming Species • Species: a group of the same type of organisms that is able to reproduce and produce fertile offspring. • Scientific Names: used by scientists to identify a specific species. • Contains two parts: Genus species • Always underlined or in italics • Genus always capitalized & species all lower case • Examples: • Homo sapiens(humans) • Pantheratigeris (Bengal Tiger) • Sequoiadendrongiganteum(Giant Redwood) • Bombuslucorum(white tailed bumblebee)

11. Species or Not?

12. Species

13. Habitat vs. Niche • Habitat: where an organism lives • The habitat must provide a source of food, water and shelter for the organism. • Niche: the role (“job”) of the organism. • This is largely to do with the trophic level of the organism. (what it eats) • Examples: • Plants make food for the rest of the food chain • Tigers keep the population of herbivores under control

14. Habitat • Can habitat’s change? • Immigration • Migration

15. Fundamental vs Realized Niche • No two species can have the same ecological niche in the same place at the same time! • Fundamental Niche: the entire range of conditions in which a species could live • Realized Niche: the actual conditions under which the species lives (usually due to competition)

17. Limiting Factors • Factors in an ecosystem that limit the population size if there are is too much or too little of it. • Sunlight • Precipitation • Salinity • Nutrients in the soil • Food • Limiting factors cause a reduction in population growth as they become in short supply.

18. Carrying Capacity • The maximum number of organisms of a single species that an ecosystem can support • Population Dynamics: the study of the change in populations over time • We use population graphs to look at the changes in populations over time. • Sketch what a population growth curve would look like if there were no limiting factors.

19. Population Growth Curves • Without limiting factors, there will be exponential growth (there is nothing limiting population size) • Is this realistic for most populations? Justify your answer!

20. S-Curves • Start with exponential growth • Slow as they limiting factors become scarce • When population reaches carrying capacity (K) there is no longer growth • Where exponential growth slows until we reach carrying capacity is called environmental resistance Environmental resistance

21. S-Curves • In reality populations tend to fluctuate around the carrying capacity. • What is this an example of? • Negative Feedback

22. J-Curves • Show a boom and bust pattern • Population grows exponentially • Sudden collapse called a dieback • Often the population exceeds carrying capacity which is called overshoot • Typical of microbes, invertebrates, fish and small mammals • Can you think of any other populations that might show this type of curve?

23. What type of Population Growth?

24. What type of Population Growth?

25. Interactions Between Organisms • Through this activity you should learn about different types of interactions between organisms and how these interactions affect the populations dynamics of the organisms involved. • Relationships between Organisms Class Jigsaw Activity • Check your email for a description of requirements!