Chapter 5

1. Chapter 5 Biodiversity, Species Interactions, and Population Control

2. 5-1 How do species interact?

3. Vocab Interspecific competition- Occurs when members of two or more species interact to gain access to the same limited resources (food, water, light, and space) Predation- Occurs when a member of one species feeds directly on all or part of a member of another species Parasitism -Occurs when one organism feeds on another organism usually by living on or in the host

4. Vocab Mutualism- Is an interaction that benefits both species by providing each with food shelter or some other resource Commensalism-Is an interaction that benefits one species but has little or no affect on the other Resource partitioning- species competing for similar scarce resources evolve specialized traits that allow them to share resources Coevolution- when populations of two different species interact with each other for a long period of time that changes in the gene pool in one population can affect the gene pool of the other

5. Science focus Threats to kelp forests Composed of large concentrations of giant kelp One of the most biologically diverse ecosystems Help reduce shore erosion Sea urchins and pollution are major threats Sea otters help control sea urchins

6. Science focus Runoff containing pesticides and herbicides can kill kelp plants and kelp forest species Fertilizer runoff causes excessive growth of algae and other plants that block sunlight to the giant kelp Warming water will cause kelp forests to disappear

7. General information Each species plays a role in its ecosystem called its ecological niche Camouflage and chemical warfare is used by both predator and prey Warning coloration and behavioral strategies are used by the prey to confuse the predator

8. 5-1 Key concept: Five types of species interactions- competition, predation, parasitism, mutualism, and commensalism- affect the resource use and population sizes of the species in the ecosystem

9. 5-2 What limits growth of population?

10. Vocab Age structure- percentage of population at various ages Range of tolerance- rage of chemical and physical conditions that must be maintained for survival of life Limiting factors- factors that limit the growth abundance or distribution of a species in an ecosystem Limiting factor principle- “too much or too little of any abiotic factor can limit or prevent growth of a population of a species in an ecosystem, even if all other factors are at or near the optimal range of tolerance for the species”

11. Vocab Carrying capacity- maximum population of a particular species that a given habitat can support over a given period Population crash- die back of population that has used up its supply of resources exceeding the carrying capacity of its environment Population density- number of organisms found in a particular population found in a specified area

12. Science focus Why do California sea otters face an uncertain future? Females are sexually mature at 2-5 years Can produce pups until 15 years old Only has 1 pup a year Orcas prey on otters when their natural prey populations started declining Parasites from flushed cat litter Run off fertilizer and other chemicals

13. General information Changes in the population size of keystone species can alter the species composition and biodiversity in ecosystems Humans are not exempt: potato crisis, bubonic plague, AIDS

14. 5-2 Key concept: no population can continue to grow indefinitely because of limitations on resources and because of competition among species for those resources

15. 5-3 How do communities and ecosystems responding to changing environmental conditions?

16. Vocab • Ecological succession- process in which communities of plant and animal species in a particular ecosystem are replaced over time by a series of different and more complex communities • Primary- involves the gradual establishment of biotic communities in lifeless areas • Secondary- a series of communities or ecosystems with different species develop

17. Vocab Persistence- the ability of a living system to survive moderate disturbances Resilience- the ability of a system to be restored through secondary succession after a more sever disturbance

18. Science focus How do species replace one another in ecological succession? • Three ways- • Facilitation: one set of species makes an area suitable for species wit different niche requirements but less suitable for itself • Inhibition: some early species hinder the establishment of growth of other species • Tolerance: plants in late stages of succession are largely unaffected by plants that came in during earlier stages because the later plants are not in direct competition with the earlier ones for key resources

19. General information Primary and secondary ecological succession are important natural services that tend to increase biodiversity by increasing species richness and interaction among species Ecological succession proceeds in an orderly fashion until a stable climax community is reached and starts over when that community is destroyed

20. 5-3 Key concept: the structure and species composition of communities and ecosystems change in response to changing environmental conditions through a process called ecological succession