Populations of different species = COMMUNITY

1. INTERACTIONS WITHIN A COMMUNITY Populations of different species = COMMUNITY This illustration presents a community of interacting living and non-living organisms. Producers, consumers, decomposers, and abiotic matter form an integrated, functioning whole driven by the sun’s energy.

2. Community (DONT WRITE) consists of populations of different species (plants and animals) living and interacting in the same place at the same time. • This populations/organisms depend on one another. • The composition of community is called community structure (animals and plants) • The relative abundance of any other species can affect the abundance/number of other species, • And thus alter community structure in an ecosystem

3. Flow of Energy in an Ecosystem Grade 10 revision The sun is the original source of energy in an ecosystem.. Since energy is lost in each step, populations are necessarily smaller at each higher level of the pyramid.

5. Five Main Types of Interactions in a Community • Populations of a community interact and affect one another in a variety of ways. • The interaction can either be harmful or beneficial to organisms involved. • The interactions are:- • Predation • Mutualism • Competition • Parasitism • Commensalism

6. KNOW FOR THIS SECTION!!! • Name of interaction • Definition • South African e.g.

7. PREDATION Species that captures, kill and eat other species – predation Lionesses hunt in teams to bring down large animals such as the buffalo in this picture An African fish eagle flies off from the surface of the Okavango River, Botswana, clutching a tiger fish

8. PREDATION • Predation is the feeding interaction between the predator and prey. • The predator is an animal that hunt, capture and kill other animals (prey) for • food. • The prey is the animal being hunted and killed. • In this way the number of prey might fluctuate(because of availability of • food, shelter, etc). • This in turn causes a corresponding fluctuation in predators. Predation is a density-dependent factor

9. Predator-prey relationshipspg 296-297

10. ACT 3.2.2 pg 298 no 1 only

11. Competition • Competition • Occurs when a large number of organisms depend on a common source that • is in short supply. • Competition (plants) • can be for :- light • :- water minerals • :- space • :- food (animals) • :- nesting/shelter/space • :- mating partners Species may compete for various resource

12. 1. Intraspecific competition: the competition between organisms of the same species depending on the same resources like food, space, shelter, water and access to mates.2. Interspecific competition: the competition between organisms of different species depending on the same resources e.g. light, space, water, shelter, food Within Species Species Between

13. Competition: Intraspecific competition

14. Intraspecific competition: males compete for territory.

15. Gemsbuck fighting for mating partners

16. Interspecific competition:In the African savanna, hyenas and vultures compete with one another for the flesh of dead animals such as the dead elephant pictured here.

17. Interspecific competitionLion and hyenas fighting for the same food resources

18. Jackal and a hyena fighting for the same food source

19. In plants competition for light in tropical forests, • Tall trees extend above canopy forming umbrella-shape. • Coniferous trees (lacking broad leaves absorb pale light. • Vines (which have their roots in soil), epiphytes (climbers), climb on tall trees to reach light

20. Competitive exclusion 1. Competitive exclusion: the competition in which one of the two competing species is much more successful that the other such that the successful species survives and the other species disappears.

21. Competitive exclusion

22. Paramecium aurelia and P. caudatum: In a classic study in the 1930’s, Gauss cultured P. aurelia and P. caudatum both alone and together in culture tubes.  When grown separately, the populations grew to a fairly predictable density.  However, when grown together, P. caudatumalways lost and eventually went extinct.

23. Resource partitioning 2. Resource partitioning: The kind of competition situation in which competing species coexist in the same habitat since they use the resources slightly differently

24. Resource partitioning amongst plants Different species of plants in the same habitat will compete for the same resources like light, water, mineral salts, etc. Different species of plants grow to different heights or have roots that are different lengths so they divide the resources, accessing them in slightly different ways

25. Resource partitioning: co-existing shore birds

26. Specialisation of the Galapagos finches

27. Resource partitioning amongst animals Resource partitioning is a kind of competition situation in which competing species coexist in the same habitat since they use the resources slightly differently

28. Symbiosis Together living • A close interaction between two organisms such that at least one benefits.

29. Symbiosis Individuals of two or more species live in direct and intimate relationships. Required for survival by one or both species Mutualism Obligatory. Both species benefit. Examples: *Animals:Birds and grazing animals *Plants: Bees and flowers Commensalism One species benefits; the other species is not harmed. Examples: *Animals: Barnacles on whales *Plants: Epiphytes growing on trees Parasitism Parasite is dependent and benefits; Host is harmed Examples: *Animals:Ticks on grazers *Plants:Dodder on angiosperms

30. Parasitism: a relationship in which one of the species (parasite) benefits and the other (host) is harmed by the relationship Parasitism: malaria mosquito sucking human blood

31. Life cycle of the malaria mosquito

32. Parasitism: Ticks feeding on animals or humans

33. A tick bite can cause tick bite fever in humans

34. Parasitism: swimming habits may influence parasitic infections

35. World distribution of bilharzia

36. Sanitation may influence parasitic infections

37. Platyhelminthes: taenia solium/tapeworm

38. Tapeworm with hooks with which it attach to the wall of the small intestine

39. Life cycle of a tapeworm

40. . Fish Louse The fish louse, Anilocra capensis, is parasitic on fish. Fish lice chew on the surface flesh and inflict wounds that can become infected, eventually resulting in the death of the host

41. Mutualism The symbiotic relationship in which both of the species benefit from the association.

42. Mutualism: oxpeckers on a giraffe. The oxpecker gets food from the giraffe and the giraffe benefits by getting rid of its parasites Mutualism:

43. Mutualism: Lichens is an organism made up of fungi and algae. The fungus provides the external structure of the lichen and provides the algae with a protected place to live. Algae photosynthesise and provide the fungus with food. Mutualism:

44. Bacteria and roots of leguminous plants (e.g. soybeans, beans) • Bacteria convert nitrogen to nitrate and ammonium. • Plants use nitrate and ammonium for acid and protein productions. • Bacteria get carbohydrates (food) from plants. • In this way both organisms (bacteria and plants) benefit from the relationship.

45. Bees collect pollen and nectar from flowers, flowers are pollinated in the process Mutualism

46. Ants get nectar from the Acacia tree as well as shelter in specialised swollen thorns. Ants defend the tree against herbivorous and wood boring insects. Mutualism Mutualism:

47. Commensalism Two species living together where one species benefits and the other neither benefits nor suffers any disadvantage

48. Commensalism: The egret catch insects which are disturbed by the activity of a large animal. The herbivore are neither helped nor harmed by the egret

49. Whale and barnacles • Barnacles are attached to skin of whales. • In this way are moved around to get fresh foods. • Without spending more energy. • The whale is not harmed nor benefit from the association

50. Remora fish swim next to sharks or attach to them. It gets protection and scraps of leftover food from the shark. The shark is neither helped nor harmed by the remora fish Commensalism: