Biodiversity and population

You can check out the video on YouTube.

Why is biodversity important? -Kim Preshoff

1. Biodiversity, Species Interactions, and Population Dynamics Prepared by: Cyrus Vincent Eludo MASEd – Physics Integrated Science IV

2. Objectives At the end of this module you are expected to: Explain how species diversity increases the probability of adaptation and survival of organisms in changing environments Identify the five types of species interactions Explain the relationship between population growth and carrying capacity Discuss population dynamics Suggest ways to minimize human impact on the environment

3. Pre-test Assessment

4. Pre-test Assessment What do you call the variety of species in a population or an ecological community? Bioaccumulation Bioalteration Biodiversity Biomagnification

5. Pre-test Assessment Which of these kinds of biodiversity refers to the variety of kinds of species living in an ecological community? Ecosystem diversity Functional diversity Genetic diversity Species diversity

6. Pre-test Assessment What term refers to the relationship between members of two or more species interacting to use the same limited resources such as food, water, light, and space? Commensalism Interspecific Competition Mutualism Parasitism

7. Pre-test Assessment What kind of relationship pertains to one species feeds on another organism, usually by living on or inside the host? Commensalism Interspecific Competition Mutualism Parasitism

8. Pre-test Assessment What do you call the interaction between species when both species involved gain nothing but benefits? Commensalism Mutualism Parasitism Predation

9. Pre-test Assessment What is the term used when one species feeds directly on all or part of a living organism? Interspecific Competition Mutualism Parasitism Predation

10. Pre-test Assessment Which of these statements does NOT contribute to the a population’s environmental resistance? High reproductive rate Inability to adapt to environmental change Specialized niche Too many competitors

11. Pre-test Assessment Which of the following refers to a group of individuals of a single species that lives in a specific area? Community Ecosystem Population None of the above

12. Pre-test Assessment What is the maximum population of a given species that a particular habitat can sustain indefinitely? Carrying Capacity Ecological Succession Environmental Resistance Population Crash

13. Pre-test Assessment What model represents a slow growth in population as it approaches the habitat’s carrying capacity? Exponential Growth Linear Growth Logistic Growth Population Growth

14. Biodiversity Click on the picture!

15. What is biodiversity? Video feedback

16. Why is biodiversity important? Video feedback

17. Will an ecosystem collapse if one species was removed from it? Video feedback

18. Topic in Focus

19. What is biodiversity? Biodiversity can be described as the quantity of species (flora and fauna) present in an ecosystem It can be further classified into four types namely: Species diversity Genetic diversity Ecosystem diversity Functional diversity (nutrient cycling)

20. Species Diversity

21. Species Diversity One of the components of biodiversity which pertains to the number and variety of the species present in any biological community. The earth’s variety of species contains even greater variety of genes, which enable life on earth to survive and adapt to dramatic environmental changes.

22. Species Diversity A species’ ecological niche is the role that it plays in an ecosystem or the total set of biotic and abiotic resources it uses. This include the food it eats, the water it drinks, the space it occupies and any other resource the species uses.

23. How do species interact?

24. Kinds of Interaction of Species Interspecific Competition Predation Symbiosis Parasitism Mutualism Commensalism

25. Can two species have the exact same niche in a habitat? Why or Why not? Something to Ponder

26. Interspecific Competition Intraspecific Competition

27. Interspecific Competition Competition between organisms of different species which, in some cases, are easy to identify—such as when animals battle over food. Some (organisms) don’t necessarily fight each other directly as they compete any time they use the same resource. Example: Plants growing near each other compete for limited sources such as sunlight, water, and soil nutrients.

28. Interspecific Competition Since NO two species can share vital limited resources for long Interspecific competition can be resolved by: Migration Shift in feeding habits or behavior Population drop Extinction

29. Interspecific Competition (Some) intense competition lead to resource partitioning This partitioning occurs when species competing for similar scarce resources evolve specialized traits that allow them to share resources by using parts of them, using them at different times, or using them in different ways.

30. Sharing the wealth Resource partitioning among five species of insect-eating warblers in the spruce forests in Maine, US. Fig. 5-2, p. 81

31. Sharing the wealth Each species spends at least half of its feeding time in its associated yellow-highlighted areas of these spruce trees. Cape May Warbler Blakburnian Warbler Black-throated Green Warbler Yellow-rumped Warbler Bay-breasted Warbler

32. Why do you think the warblers have come to such similar yet non-identical niches? Something to Ponder

33. Scientists believe that the niche differences were produced by evolution through natural selection. Individual of each warbler species were more successful at surviving and reproducing if they competed less with individuals of other species Something to Ponder

34. Predation

35. Predation A relationship that is evident in the food chain (and food web) which shows one organisms feeding off on another organism The predator feeds directly on all or part of the prey Predators are usually carnivores and found on higher trophic levels.

36. A Species in Recovery Southern sea otters live in giant kelp forests in shallow waters along part of the Pacific coast of North America . Studies indicate that they act as a keystone species—species that play role affecting many other organisms in an ecosystem .

37. A Species in Recovery Otters use stones to pry shellfish off rocks under water then resurfaces to the water and as they swim on their backs, they break open the shells by cracking them against a stone. Each day, an otter consumes ¼ of its weight in clams, mussels, crabs, abalones, sea urchins, and other bottom-dwelling organisms. An adult southern sea otter can eat up to 50 sea urchins a day—equivalent to a 68-kilogram person or 160 quarter pounders!

38. A Species in Recovery Without these sea otters, scientists hypothesize that sea urchins and other kelp-eating species would probably destroy the kelp forests and much of the rich biodiversity of species they support.

39. Threat to Kelp Forests Sea urchins and pollution are major threats to kelp forests. Acting as predators, a large populations of sea urchins can rapidly devastate a kelp forest because they eat the bases of young kelp plants.

40. Threat to Kelp Forests Kelp forests are one of the most biologically diverse ecosystems found in marine waters, supporting large numbers of marine plants and animals. They* help reduce shore erosion by blunting the force of incoming waves . People harvest kelp as a renewable source, extracting a substance called algin from its blades. This substance is used as a thickening agent in toothpaste, cosmetics, ice cream and hundreds of other products.

41. What simple ways can you do protect giant kelp forests and southern sea otters? Name at least three. Something to Ponder

42. Individuals of two species live in close association with one another. Symbiosis

43. Parasitism

44. Parasitism Occurs when the parasite feeds on another organism, usually by living on or inside the host . The parasite benefits and the host is often harmed but not immediately killed. A parasite is also usually is much smaller than its host and rarely kills it. However most parasites continue to draw nourishment from then and may gradually weaken them over time

45. Parasitism Some parasites such as sea lampreys (picture on the right) attach themselves to their host, in this case, an adult lake trout. From the hosts’ point of view, parasites are harmful.

46. Parasitism But from the population perspective, parasites can promote biodiversity by contributing to species richness or sometimes help keep the populations of their hosts in check.

47. What are some examples of parasites that harm human beings? Check Yourself

48. Mutualism

49. Mutualism Occurs when two species behave in ways that benefit both by providing each with food, shelter, or some other resource. Examples include pollination of flowering plants by species such as honeybees and butterflies that feed on the nectar of flowers.

50. Mutualism Birds that ride on the backs of large animals like rhinoceros. The birds remove and eat parasites and pests from the animals’ bodies (also send out warning from incoming predators by making noises)

51. Is mutualism an example of cooperation between the two species involved? Justify your answer. Something to Ponder

52. Commensalism

53. Commensalism An interaction that benefits one species but has little, if any, beneficial or harmful effect on the other. Example includes epiphytes (air plants) such as certain types of orchids that attach themselves to the trunks or branches of large trees commonly found in tropical forests (see photo from previous slide)

54. What other examples of commensalism can you think of? Give at least two. Check Yourself

55. Population Dynamics

56. Population Dynamics A population is a group of individuals of the same species living in particular place. The size of a population is governed by four variables namely: births, deaths, immigration, and immigration. Immigration – arrival of individuals from outside the population Emigration – departure of individuals from the population

57. Population Dynamics The equation widely used to determine the size of a population is presented below: Population change = (Births + Immigration) – (Deaths + Emigration) The presence or absence of certain physical and chemical factors—limiting factors—can also help to determine the number of organisms in a population

58. Population Dynamics Populations vary in their capacity for growth, also known as biotic potential . Intrinsic rate of growth (r) is the rate at which a population will grow if it had unlimited resources. Carrying capacity (K) : The number of individuals in a population that can be supported in a given area.

59. Population size ( N ) Time ( t ) Carrying capacity ( K ) Environmental resistance Biotic potential Exponential growth

60. Population Dynamics Factors that tend to increase or decrease population size: Biotic potential and environmental resistance determines the carrying capacity (see the next image)

61. Population Density affects Population Growth Density-dependent population controls are reliant on a dense population for effect: Pests Infectious diseases Competition for resources Predation Density-independent population controls affect population size regardless of density: Weather Fire Habitat destruction Pesticides Pollution

62. Carrying Capacity There are always limits to population growth in nature . Carrying capacity (K) is the number of individuals that can be sustained in a given space If the carrying capacity for an organism is exceeded, resources are depleted, environmental degradation results, and the population declines .

63. Carrying capacity is determined by climatic changes, predation, resource availability and interspecific competition.

64. Exponential vs Logistic Growth Exponential growth occurs when resources are not limiting. Logistic growth occurs when resources become more and more limiting as population size increases. © Brooks/Cole Publishing Company / ITP

65. Exponential Population Growth During exponential growth population size increases faster and faster with time Currently, the human population is undergoing exponential growth Exponential growth can not occur forever because eventually some factor limits population growth.

66. Logistic Population Growth Logistic population growth occurs when the population growth rate decreases as the population size increases. Note that when the population is small the logistic population growth curve looks like exponential growth Over time, the population size approaches a carrying capacity (K).

67. Exceeding the Carrying Capacity During the mid–1800s sheep populations exceeded the carrying capacity of the island of Tasmania. This "overshoot" was followed by a "population crash". Numbers then stabilized, with oscillation about the carrying capacity . © Brooks/Cole Publishing Company / ITP

68. Exceeding the Carrying Capacity Reindeer introduced to a small island off of Alaska in the early 1900s exceeded the carrying capacity, with an "overshoot" followed by a "population crash" in which the population was totally decimated by the mid–1900s. © Brooks/Cole Publishing Company / ITP

69. Do humans contribute in lowering the carrying capacity of certain animals? Explain your answer. Something to Ponder

70. Case Study

71. The Philippine Eagle

72. Getting to know the Philippine Eagle The Philippine monkey-eating eagle is well named for its preference for eating monkeys, particularly macaques. They inhabit tropical rain forests and are well-adapted to life in dense foliage. They are adept at snatching monkeys or other mammals or birds from trees.

73. Like most big predators, they require a large territory for hunting.

74. Philippine eagles also require the tallest trees, those which emerge above the rain forest canopy, for nesting. Where they reproduce at a slow rate, laying just one or two eggs each year.

75. What are the causes of its endangerment? Habitat Loss Hunting Pollution Collectors A Philippine eagle ( Pithecophaga jefferyi ) on its nest. 

76. Which of the factors mentioned greatly affects the species’ endangerment? Explain your answer. Check Yourself

77. How can we help protect the Philippine eagle? Something to Ponder

78. Recapitulation Biodiversity is the variety of life in the world or in a particular habitat or ecosystem One of the examples of biodiversity is species diversity where the presence of many kinds of organisms make way to species interactions Interaction of species ensures survival of many organisms even in changing environments Population growth can be determined by the number of births and deaths

79. Recapitulation Exponential growth occurs when there is unlimited resources so its size increases at a greater and greater rate. Logistic population growth occurs when the growth rate decreases as the population reaches carrying capacity. Carrying capacity is determined by climatic changes, predation, resource availability and interspecific competition.

80. Recapitulation Logistic population growth occurs when the growth rate decreases as the population reaches carrying capacity . Humans activities such as deforestation pose great risks to wildlife such as the Philippine eagle Understanding biodiversity and population, you may be able to help take care of it

81. How can we help protect these animals? This lesson will help you understand biodiversity and its importance to the ecosystem By knowing how these two components work together, you may be able to help take care of it

82. Charles Darwin “In looking at nature, never forget that every single organic being around us may be said to be striving to increase its numbers.”