_2.1_individuals_populations_communities_and_ecosystems.pptx

Topic 1

1. 2.1 Individuals, Populations, Communities, and Ecosystems

2. Guiding Questions How can natural systems be modelled, and can these models be used to predict the effects of human disturbance?​ How do population dynamics such as birth rates and death rates influence the stability of an ecosystem?

3. 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.

4. ECOSYSTEMS FOUNDATION

5. 2.1.1 Earth’s Systems There are various systems of the Earth: biosphere atmosphere geosphere hydrosphere cryosphere. Watch the video and answer Q1

6. 2.1.1 The Biosphere A biosphere represents the parts of the Earth where life exists, from the upper parts of the atmosphere to deep within the Earth’s crust.

7. 2.1.1 The Biosphere Watch the video and answer Q2

8. 2.1.1 Key Elements of the Biosphere Ecosystems Communities Populations Individuals

9. 2.1.1 Key Elements Ecosystems: comprise communities and their non-living environments functioning as a single unit. The health of ecosystems is often gauged by their biodiversity, productivity, and the cyclic movements of energy and nutrients. https://www.cfwt.sua.ac.tz/ecosystems/ecosystems-and-conservation

10. 2.1.1 Key Elements Communities: a group of populations of different species that live in the same area and interact with each other. These interactions can include various forms of symbiosis, competition, and predation. https://www.noble.org/regenerative-agriculture/how-to-keep-community-dynamics-healthy-on-the-ranch/

11. 2.1.1 Key Elements Populations: a group of individuals of the same species living in a specific area, capable of interbreeding. Population dynamics, such as growth rates and migration, play a crucial role in the health and evolution of ecosystems https://www.expii.com/t/population-ecology-definition-examples-10287

12. Individuals: The smallest unit in the ecological hierarchy, an individual is a single organism capable of independent survival. https://naturemuseum.org/chicago-academy-of-sciences/blog/national-bison-day 2.1.1 Key Elements of the Biosphere

13. 2.1.2 Species Species - a group of organisms that can interbreed and produce fertile offspring. A species is often defined as a group of individuals that actually or potentially interbreed in nature. In this sense, a species is the biggest gene pool possible under natural conditions .

14. 2.1.2 Species

15. 2.1.2 Species Bengal Tiger Individual Organism: Name: Raja Species: Bengal Tiger ( Panthera tigris tigris ) ​Raja is an individual Bengal Tiger living in the Sundarbans mangrove forest in India. As a member of the species Panthera tigris tigris, Raja shares several characteristics with other Bengal Tigers, including physical traits, behaviors, and genetic makeup https://www.nationalgeographic.com/animals/mammals/facts/bengal-tiger

16. 2.1.2 Species

17. Species or Not? https://www.quora.com/How-do-donkeys-look-like-the-mule 2.1.2 Species

18. 2.1.2 Species Model The species model, often used in environmental studies and conservation, involves focusing on individual species for protection and management. While this approach has its merits, it also has several problems and limitations: Narrow Focus: biodiversity is overlooked, ecosystem Interactions are ignored: Resource Allocation: funding and effort imbalanced, inefficiency in funds Ecological Complexity : species may not exist or keystone species misidentification: Climate Change Adaptation: does not account for the dynamic nature of ecosystems, adaptation needs are not met E thical Considerations: The model can reinforce an anthropocentric views prioritizing certain species can lead to conflicts with local communities,

19. 2.1.2 Species Model The species model, often used in environmental studies and conservation, involves focusing on individual species for protection and management. While this approach has its merits, it also has several problems and limitations: Policy and Legislation : Conservation laws and policies often target specific species and create fragmented approaches: Short-term Focus: prioritize immediate conservation actions over long-term ecological health, potentially ignoring factors like genetic diversity and ecosystem resilience. Sustainability : ensuring the sustainability of species populations often requires addressing broader environmental issues such as habitat destruction, pollution, and climate change, which the species model may not fully encompass

20. 2.1.3 Why Do We Classify What am I? Firefly Lightning bug Glow Fly Blinkie Golden Sparkler Moon bug Glühwürmchen Luciérnaga Luciole We all have different names for the same organism…this is a problem for communication.

21. 2.1.3 Why Do We Classify

22. 2.1.3 Why Do We Classify The classification of organisms, also known as taxonomy, is a critical scientific system used to organize and categorize the vast diversity of life forms on Earth. The system of biological nomenclature (naming) developed by Charles Linnaeus

23. Either written in italics or underlined Genus is always capitalized and species is always lowercase Based on Latin Examples: Cat: Felix domesticus Mosquito: Colex pipens Human: Homo sapien 2.1.3 Classification

24. Agra vation (a beetle) Colon rectum (another beetle) Ba humbugi (a snail) Aha ha ( a wasp) Lalapa lusa (a wasp) Leonardo davinci (a moth) Abra cadabra (a clam) Gelae baen, Gelae belae, Gelae donut, Gelae fish, and Gelae rol (all types of fungus beetles) Villa manillae, Pieza kake and Reissa roni   (bee flies) 2.1.3 Funny Names

25. Allows for efficient identification and prediction of characteristics. dichotomous keys comparison with specimens in reference to collections by expert taxonomists, deoxyribonucleic acid (DNA) surveys. 2.1.4 Classification of Organisms https://www.mdpi.com/2410-3888/9/4/147

26. A dichotomous key is composed of a series of questions or statements based on the physical characteristics of the organisms concerned and operates as a kind of flow chart 2.1.4 Dichotomous Keys

27. 2.1.4 Dichotomous Keys

28. 1a. Hair Present…………..Class Mammalia 1b. Hair Absent……………Go to statement 2 2.1.4 Dichotomous Keys

29. Advantages Disadvantages Easy to use May require some prior knowledge of terminology such as antenna, dorsoventral etc. Easy to construct Some organisms look very different at different stages in their life cycle Parts of the organism may be damaged –lost a tail, leg, etc. 2.1.4 Evaluation of Dichotomous Keys

30. Complete the dichotomous key from salamander species Remember Each decision point – only TWO options Yes or no descriptions are best 2.1.4 Dichotomous Keys - Activity - Q10

31. Watch the video. Identify the biotic and abiotic components of a ecosystem Q 11 2.1.6 Biotic and Abiotic Components - Q11

32. River dolphin Algae Daylight hours Precipitation Moss Soil composition 2.1.6 Biotic and Abiotic Components - Q12 Bacteria Mushroom Rocks Minerals Mangrove trees Swamp grass Identify the following as biotic or abiotic

33. Research how the following abiotic factors measure aquatic and terrestrial ecosystems; Temperature, Sunlight, pH, Salinity, Dissolved Oxygen, and Soil Texture. How it is measured? What tools are used? What role does it play in the ecosystem? 2.1.6 Activity - Measuring Abiotic Factors - Q13

34. POPULATION AND COMMUNITY DYNAMICS

35. 2.1.5 Populations Populations: a group of individuals of the same species living in a specific area, capable of interbreeding. Population dynamics, such as growth rates and migration, play a crucial role in the health and evolution of ecosystems https://www.expii.com/t/population-ecology-definition-examples-10287

36. 2.1.5 Key Characteristics Interbreeding Capability: Populations are defined by the potential for members to reproduce and exchange genes, which is essential for adaptation and survival. Spatial and Temporal Boundaries: Populations are confined to specific areas, but these boundaries can change due to various factors. Populations are also dynamic, changing over time. Multiple Populations for One Species: A single species can have multiple populations separated by geography, environment, or behavior, leading to different evolutionary paths.

37. The shaded patches in this map of the United States shows different wolf populations. Because the patches are separated by barriers-mostly areas with large human presence and minimal wolf habitat-the wolves do interact with each other. All the wolves in the US are the same species, but they split into different populations 2.1.5 Population Change

38. These amphibians all share a common ancestor Populations of the ancestral amphibian were isolated by geographic factors Different environmental factors in each part of the ecosystem selected different characteristics favoring survival in that habitat Overtime they have become different species 2.1.5 Population Change

39. 2.1.5 Activity Examine a population of a specific tree species within a local forest or woodland area.

40. 2.1.8 Ecological Niche A niche describes the particular set of abiotic and biotic conditions and resources upon which an organism or a population depends. Encompasses the range of biotic and abiotic conditions that a species needs to survive, grow, and reproduce. https://education.nationalgeographic.org/resource/niche/

41. 2.1.8 Ecological Niche

42. 2.1.8 Key Aspects of a Niche Resource Use: The specific resources a species needs (food, water, shelter) determine its niche. For instance, different plant species in a rainforest need varying amounts of light, nutrients, and water, which affect their growth and reproduction . Functional Role: A species' role in its ecosystem (e.g., predator, decomposer, pollinator) is a key part of its niche. This role influences its interactions with other species and its contribution to energy flow and nutrient cycling. E nvironmental Tolerances: A species' tolerance to environmental factors (e.g., temperature, humidity, pH, salinity) defines its niche. These tolerances determine where a species can live and thrive .

43. A niche may range from a unidimensional space to a multidimensional space Includes: Space utilisation Food consumption Temperature range Moisture requirements 2.1.8 Ecological Niche

44. It looks like these warblers all occupy the same niche, but that is not true Each warbler species prefers to feed at different height and portion of the tree, thus reducing competition 2.1.8 Ecological Niche

45. If two species have an identical or very similar niches they cannot live in the same habitat. The Eurasian red squirrel and Eastern grey squirrel both eat very similar foods. The grey squirrel outcompetes the red squirrel 2.1.8 Ecological Niche

46. A summary of niche complementarity and overlap in functional groups of pollinators, showing effects of plant species richness, time of day, and flowering height on flower visitation rate of each group. 2.1.8 Ecological Niche Reference the graph and complete Q19

47. 2.1.8 Niche - Activity -Q20 Gather information on a species of your choice: Habitat Requirements: Where does the species live? Diet : What does the species eat, and what role does it play in the food chain? Behavioral Traits: How does the species behave in different seasons or stages of life? Environmental Tolerance: What range of temperatures, altitudes, or moisture conditions can the species tolerate? Interactions with Other Species: Does it compete with other species? Does it have any predators or mutualistic relationships?

48. A species interaction is the effect that a pair of organisms living together in a community have on each other herbivory predation parasitism mutualism disease competition https://www.ck12.org/book/human-biology-ecology/section/9.1/ 2.1.9 Population Interactions

49. https://www.ck12.org/book/human-biology-ecology/section/9.1/ 2.1.9 Population Interactions

50. 2.1.9 Population Interactions - Activity - Q21 Identify two named examples in an ecosystem for each specific type of interaction between organisms: Competition (inter- and intra-species) – include competitive exclusion Disease Mutualism Parasitism – include important vocab. Predation – include at least 1 graph that shows how negative feedback is involved Herbivory – at least 1 must include a plant with a defense mechanism

51. 2.1.9 Population Interactions - Activity 2 - Q23 The predator-prey relationship is a fundamental concept that illustrates the dynamic interactions between two species: one as the predator and the other as prey. This relationship is often modeled through causal loop diagrams that help in understanding how various factors affect the populations of these two interdependent species.

52. https://www.ck12.org/book/human-biology-ecology/section/9.1/ 2.1.9 Population Interactions - Activity 2 In this simulation lab you will use the predator-prey model to demonstrate feeding relationships over time. The simulation will allow you to manipulate variables such as reproduction rates, initial population sizes, and resource availability to see how these factors influence the stability and oscillations of predator and prey populations.

53. 2.1.10 Carrying Capacity Carrying capacity - the average population size of a species or “load” that can be sustainably supported by a given environment.

54. 2.1.10 Carrying Capacity Watch the video and complete Q24

55. 2.1.10 Resources Affecting Carrying Capacity Food Availability: Water Resources:. Habitat Space: Predation and Disease: Climate Human Impact:

56. 2.1.10 Exceeding Carrying Capacity Resource Depletion Reduced Reproduction and Growth Rates Increased Disease and Parasite Spread Habitat Degradation and Loss Ecological Imbalance Decline in Biodiversity Human-Induced Conflicts Unstable Social and Economic Environmental Collapse https://socratic.org/biology/change-in-communities/carrying-capacity

57. 2.1.10 Activity - Q28 In your groups identify a specific ecosystem to study (e.g., tropical rainforest, desert, coral reef, temperate forest). research the key biotic and abiotic factors that affect the carrying capacity of your ecosystem describe the characteristics of your ecosystem. detailed explanations of how each identified biotic and abiotic factor influences the carrying capacity. Real-world examples that illustrate these impacts (e.g., how overfishing has affected the carrying capacity for certain fish species in marine ecosystems) ..

58. Population size is regulated by density-dependent factors and negative feedback mechanisms 2.1.11 Population Size

59. Density-Dependent Factors: Limiting factors that contribute to determining carrying capacity while depending on the density of the population. Density-Independent Factors: Unlike density-dependent factors, these limiting factors affect the population regardless of its size .. 2.1.11 Population Size

60. Competition for Resources Predation and Herbivory Disease and Parasites Intraspecific Interactions Territoriality 2.1.11 Density-dependent Factors

61. Climate and Weather Natural Disasters Habitat Destruction Availability of Abiotic Factors Human Activities 2.1.11 Density-independent Factors

62. The interplay between density-dependent and independent factors provides a complex framework through which ecosystems regulate population sizes. These mechanisms operate to return a population to its equilibrium state when it deviates from the carrying capacity 2.1.11 Feedback Mechanisms

63. 2.1.13 Feedback Mechanisms Watch the video and answer Q30

64. ​Population growth patterns are fundamental concepts in ecology, reflecting how populations expand under various environmental conditions and constraints. Two main types of population growth curves: S-curve (logistic growth) and J-curve (exponential growth). 2.1.13 Population Growth

65. Without limiting factors, there will be exponential growth (there is nothing limiting population size) Is this realistic for most populations? Justify your answer! 2.1.12 J Curves Certain species of algae and insects like locusts show exponential growth during specific seasons, followed by a sudden decrease in population at the end of the season

66. Key Points: This type of growth assumes unlimited resources, no competition, and no other environmental constraints. Under these ideal conditions, every individual has the same chance of surviving and reproducing, leading to rapid population increases 2.1.12 J Curves

67. S-Curves When resources are limited - they are limiting factors. Exponential growth is only possible for a short period of time because as the population grows resources are depleted and the growth rate slows and will eventually plateau off. This type of curve is typical of k-strategists. Environmental resistance 2.1.12 S Curves Many wildlife populations, such as deer in a regulated forest environment, follow logistic growth

68. S-Curves Key Points: As the population approaches its carrying capacity, density-dependent factors such as competition for food, predation pressure, and disease prevalence increase, slowing down the growth rate and stabilizing the population size. Environmental resistance 2.1.12 S Curves

69. S-Curves 2.1.12 S Curves

70. Some populations exhibit "boom and bust" patterns, characterized by rapid increases in population size followed by sudden declines, often well below the initial starting point. 2.1.12 Boom and Bust Cycles The reindeer population on St. Matthew Island is a classic example of a boom and bust cycle.

71. Investigate the reindeer population on St. Matthew Island case study 2.1.12 Activity - Q35

72. 2.1.13 Human Population Watch the video and complete Q36

73. 2.1.13 Human Population Human population growth has accelerated dramatically due to the reduction or elimination of many natural limiting factors, technology - protective shelters medicine - vaccines, antibiotics, and enhanced sanitation practices agricultural advancements - Green Revolution natural predators - mitigated through the development of weapons and changes to human settlements This growth has profound implications for the sustainability of ecosystems worldwide.

74. 2.1.13 Human Population Human population growth has resulted in Resource Depletion: increased demand for natural resources. Overexploitation of these resources is stripping the Earth of its natural assets faster than they can be replenished. Habitat Destruction: Expansion of urban areas, industrialization, and the conversion of land for agriculture have led to widespread habitat destruction. Reduces biodiversity, altering ecosystems irreversibly. Pollution: Industrial and agricultural activities have introduced pollutants into the air, water, and soil at rates that overwhelm the natural regenerative capacities of these ecosystems. This pollution poses severe risks to wildlife and human health alike.

75. 2.1.14 Determining Human Carrying Capacity Determining the carrying capacity for human populations presents unique challenges, The complex and dynamic nature of human ecological interactions and the unprecedented expansion of human activities create these challenges

76. 2.1.14 Dynamics of Human Ecological Niche Expansive and Evolving Niche: Human ecological niches are wide-ranging and continually evolving due to technological progress in areas from agriculture to digital technology, altering our environmental interactions. Resource Mobility: Humans uniquely transport resources globally, overcoming local shortages through trade and technology, which complicates carrying capacity calculations.

77. 2.1.14 Technological Impact on Carrying Capacity Technological Expansion: Has historically expanded the human niche by improving the efficiency of resource use and by accessing new resources. For example, advancements in desalination technology have made previously unusable ocean water a vital resource in arid regions. Consumption Patterns: Affecting the demand for various resources. Increased consumption rates, especially in developed countries, strain global resources and significantly impact ecological systems.

78. 2.1.14 Fluctuating Human Habitats Changing Environments: Rapidly changing habitats due to urbanization, deforestation, and climate change, among other factors. These changes continuously alter the environmental conditions that could be used to estimate carrying capacities. Contested Estimates: Highly disputed due to the variability in resource distribution, consumption patterns, and the impacts of technological interventions. These estimates are often only valid for the present moment, as the parameters used in their calculation can quickly become outdated.

79. 2.1.14 Equilibrium within Ecosystems Ecosystem Equilibrium: In natural settings, populations typically achieve an equilibrium with their environment, where the population size stabilizes at or near the carrying capacity. For non-human species, this equilibrium is maintained by natural checks such as predation, disease, and competition. Human Exceptionalism: Humans frequently bypass these natural checks through medical advancements, agricultural productivity, and ecological modifications, which prevent human populations from achieving a similar equilibrium. This ability to alter carrying capacities and avoid population decline from resource depletion or environmental constraints is unique to humans.

80. 2.1.14 Ecological Footprint Calculating the carrying capacity for human populations continues to be a topic of debate. One method employed to address this issue is through the use of the ecological footprint concept: Ecological Footprint: Quantifies the amount of biologically productive land and water area an individual, population, or activity requires to produce all the resources it consumes and to absorb the waste it generates. EF considers factors such as plant-based food and fiber products, livestock and fish products, timber and other forest products, space for urban infrastructure, and the absorption of carbon dioxide emissions. Carrying Capacity: The reciprocal of the ecological footprint (1 / ecological footprint) offers a theoretical estimate of carrying capacity. It suggests how many people a particular biologically productive area can sustain based on current consumption and waste production rates. This reciprocal approach provides a tangible measure to gauge the sustainability of human consumption patterns and the sufficiency of natural resource availability.

81. Measuring Populations

82. Natural environments do not generally appear as neatly organized arrangements of biotic and abiotic components Therefore, in order to study them we must impose quantifiable boundaries on them We accomplish that through various sampling strategies 2.1.15 Population Sampling

83. Estimating the abundance of a population within an ecosystem is essential for ecological research, conservation efforts, and resource management. Various sampling methods are employed to estimate population size and density, each with its own advantages and specific applications.. 2.1.15 Population Sampling

84. The number of samples to be taken depends on what you are sampling Avoid bias – this is done through  sampling strategies The sample is representative of the whole system It is necessary to take enough samples so that an accurate representation is obtained 2.1.15 Sampling Strategies

85. 2.1.15 Measurement Intervals Depend on habitat, time and effort allocated to the survey Too large means some species missed, and zonation patterns missed due to lack of observations Too small means time consuming and more data than needed

86. Samples may be arranged randomly or systematically across the landscape Stratified-samples are placed where there are obvious differences in one of the factors being investigated 2.1.15 Sampling Types

87. Least biased method. Every item has the same chance of being selected Need a map with a numbered grid Random points   Random areas   Random lines http://www.countrysideinfo.co.uk/howto.htm Advantages Disadvantages Unbiased You may not have access to some of the sample points Suitable for large populations In large study areas the sample points may miss some places 2.1.15 Random Sampling

88. This technique is often referred to at the n th  method, using this method you may select: Every 5 th  person that passes you Every meter along a transect line.. Samples every 30 minutes through the day. http://www.countrysideinfo.co.uk/howto.htm Advantages Disadvantages Easier to apply than random sampling as there is no need for a grid May be biased because places have a different chance of selection Coverage of the whole study area can be achieved Patterns may be missed or areas exaggerated 2.1.15 Systematic Sampling

89. Used when a population is known to contain subsets Usually questionnaire Need to know the size of the subset Need to have the same proportions 30% under 21 20% above 70 Combined with random and systematic Advantages Disadvantages Representative of the population so long as the proportions of the whole population are known You must know the size of the subsets to get an accurate picture Flexible – can be used in many situations as it combines the random and systematic Good for comparing sub-sets 2.1.15 Stratified Sampling

90. A measured line is randomly placed across the area in the direction of an environmental gradient Systematic sampling method A straight line that cuts through a natural landscape so that standardized observations and measurements can be made 2.1.15 Transects

91. All species touching the line are recorded along the whole length of the line or at specific points along the line Measures presence or absence of species Usually every 1 meter. 2.1.15 Line Transects

92. Belt transect is a systematic sampling method. It is a rectangular area centred on a line that is set across an area having a clear environmental gradient Slow moving animals (limpets, barnacles, snails) are collected, identified then released For plants an percent coverage is estimated Data collection should be completed by one individual as estimates can vary person to person 2.1.15 Belt Transects

93. 2.1.15 Transects

94. A quadrat is an appropriately shaped plot used to identify the area you wish to study. They are usually square or rectangular Used to study plants and non-motile animals or ones that do not move very much such as limpets on the seashore Particularly useful in homogeneous environments 2.1.16 Random Quadrat Sampling

95. Size of quadrat determined by size of organism being sampled (10 x 10 cm = 0.01 m 2 ; 0.5 x 0.5m = 0.25 m 2 , 1.0 x1.0 m = 1 m 2 or 5.0 x5.0 m = 25 m 2 ) The larger the size and larger the sample the more accurate the results 2.1.16 Quadrat Size

96. Number of species - The number of plants within the given area of the quadrat (m 2 ) Frequency- How often does a plant occur in each quadrat? Population Density- The average number of individual organisms within the quadrat area 2.1.16 Types of Quadrat Sampling

97. 2.1.16 Actual Counts The number of individuals of a particular species that are seen in the quadrat Count all individuals within a randomly placed quadrat Population density is expressed as number of individuals per square meter

98. The number of times a given event occurs How often a particular species appears in an area. Best done with a gridded quadrat This is best done with a gridded quadrat, as it is easy to count how many squares the species appears in. This technique has the same problems as counting individuals. 2.1.16 Percent Frequency

99. The number of individuals per unit area Once you know the number of individuals it is a simple calculation to establish the population density D=ni/A (D = density; n = number of individuals in species, A = sampling area) If you are using a quadrat that is 1 × 1 meter and there are 30 daisies in the quadrat then the population density is 30 daisies m-2 2.1.16 Population Density

100. Advantages Disadvantages Quick easy method to apply Very difficult with small species Accurate with large species Inaccurate with species like grass, which propagate under-ground Good for comparison over time May miss some species in layered vegetation Must be able to identify species accurately Species may look different in different life stages 2.1.16 Evaluating Actual Counts, Density and Percent Frequency

101. 1 m 1 m 1 2 3 4 5 6 7 8 9 10 11 12 12 12 13 13 16 15 14 15 14 16 17 17 18 18 19 19 20 20 21 21 22 22 23 24 23 24 2.1.16 Percent Cover The proportion of ground that is occupied or area covered by the plant/species Easily assessed if the quadrat is subdivided into 100 smaller squares Ci=ai/A​

102. 1 m 1 m 1 2 3 4 5 6 7 8 9 10 11 12 12 12 13 13 16 15 14 15 14 16 17 17 18 18 19 19 20 20 21 21 22 22 23 24 23 24   2.1.16 Percent Cover Find the percent coverage Count full squares Now combine pieces to make full squares Calculate percentage coverage

103. Advantages Disadvantages Avoids some of the problems of counting individuals Coverage can exceed 100% if the vegetation is layered Good for comparisons over time or space Difficult to assess accurately in layered vegetation May be able to identify species accurately 2.1.16 Evaluation of Percent Cover

104. The ACFOR scales were ultimately used as the basis for the SACFOR (Superabundant, Abundant, Common, Frequent, Occasional and Rare) abundance scales Percentage cover (%) ACFOR scale Score 50 Abundant 5 25-50 Common 4 12-25 Frequent 3 6-12 Occasional 2 <6 or individual Rare 1 not present 2.1.16 ACROR Scale

105. 2.1.16 Quadrat Sampling Technique

106. 2.1.16 Activity - Q 50 Use quadrat sampling estimates for abundance, population density, percentage cover and percentage frequency for non-mobile organisms and measures change along a transect. Urban Tree Canopy Assessment: Invasive Plant Species Monitoring in Piedmont Park Pollinator Habitat Evaluation in Community Gardens Surface Water Quality Assessment Along Chattahoochee River: Green Roof Biodiversity Study in Downtown Atlanta:

107. REMEMBER: IB Animal Experimentation Policy Pitfall Traps Small Mammal Traps Tullgren Funnels (invertebrates) Kick Net Pooter Aerial photography 2.1.16 Methods of Capture Motile Organisms

108. 2.1.16 Lincoln Index The Lincoln Index is an indirect method by which the size of an animal population can be estimated. It is also called the capture/mark/release/recapture method

109. If the organism is mobile we use a method called the capture-mark-recapture method We then use this data to calculate the Lincoln Index N = Total number of population n1 = Number of animals first (mark all of them) n2= Number of animals captured in second sample m= Number of marked animals in second sample 2.1.16 Lincoln Index

110. Marked animals not affected (neither in behavior nor life expectancy). Marked animals completely mixed in the population. Probability of capturing a marked animal is the same as that of capturing any member of the population. Sampling time intervals small in relation to the total time of experiment of organisms life span. Population is closed (no immigration and emigration) No births or deaths in the period between sampling. 2.1.16 Lincoln Index Assumptions

111. Emigration & Immigration Natural disaster or disturbance between captures Trap happy or trap shy individuals Organisms did not have enough time to disperse back into ecosystem Animals lost marks between recapture 2.1.16 Possible Sources of Error

112. You will use the Lincoln index to estimate population size. Make sure that you understand the assumptions made when using this method. Estimating Fish Populations in a Local Pond Urban Wildlife Monitoring Virtual Insect Population Study Classroom Small Mammal Population Study School Campus Bird Population Marking Bean Simulation 2.1.16 Activity - Q52

113. Communities and Ecosystems

114. 2.1.18 Community A community is a collection of interacting populations within the ecosystem. The interactions within these communities can range from competition for resources to predator-prey dynamics and mutualistic relationships that facilitate nutrient cycling and population control. The structure and stability of these communities are profoundly influenced by their biodiversity.

115. 2.1.18 Community Stability and Diversity High Diversity Communities: Wide variety of species, leading to complex and highly interconnected food webs. Interconnectivity provides resilience against environmental disturbances. For example, if one species is removed, others that fulfill similar ecological roles can potentially replace it, minimizing disruption to the community. Low Diversity Communities: Communities with fewer species tend to have simpler food webs. Generally less resilient because the removal of a single species can have more pronounced effects. With fewer alternative food sources or species to fulfill essential ecological roles, such ecosystems are more vulnerable to changes.

116. 2.1.18 Activity - Q54 Consider the concept of community in a local ecosystem. Use the Okefenokee Swamp as your example. Identify the following Community Interactions: Ecological Roles and Interactions: Resilience to Disturbance: Resilience to Disturbance:

117. 2.1.19 Habitat Habitat is the location in which a community, species, population or organism lives. Habitat incompasses both the geographical area and the ecological conditions that provide the necessities for survival and reproduction, including food, water, shelter, and mate availability. Each species has particular habitat requirements that reflect its ecological niche

118. 2.1.19 Components of Habitat Geographical Location: This defines the broader physical area where the species is found, such as a specific forest, river, mountain range, or coastal area. Physical Conditions : These include the climatic and environmental conditions such as temperature, humidity, soil type, water depth, and light availability, which are critical for the survival of different organisms. Ecosystem Type: The specific type of ecosystem—whether it be a desert, wetland, forest, grassland, or coral reef—provides the structural framework of the habitat. Each ecosystem type supports a unique set of species adapted to its particular conditions.

119. 2.1.19 Activity - Q56 Research a local ecosystem. Consider the concept of habitat in a local ecosystem. Identify the following Geographical Location Physical Characteristics: Biotic and Abiotic Factors Climate Conditions Vegetation Species Animal Species

120. 2.1.20 Ecosystems Ecosystems function as open systems where both energy and matter continuously flow in and out, sustaining life and enabling ecological processes Inputs: These include solar radiation (energy source), organic matter (from dead organisms), and inorganic nutrients (minerals) taken up from the environment. Processes: These represent the transformations within the ecosystem, like photosynthesis, energy transfer through food chains, and nutrient cycling. Outputs: These include heat (dissipated energy), dead organic matter (detritus), and gases released back into the atmosphere.

121. 2.1.20 Activity - Q57 Research a local ecosystem Consider the concept of ecosystem in a local ecosystem. Identify the following: Geographical Location Physical Characteristics Inputs Outputs Flows within the ecosystem Processes influencing the ecosystem Interactions and Feedback Mechanisms

122. 2.1.21 Sustainability Sustainability i s an inherent attribute of ecosystems, characterized by a delicate balance between the inputs and outputs that maintain their steady states. Inputs are balanced by outputs in a steady-state ecosystem. This equilibrium allows ecosystems to endure over extensive periods, with some, like tropical rainforests, existing for millions of years. These systems exemplify sustainability through their ability to maintain stability despite external disturbances.

123. 2.1.21 Sustainability Watch the video and complete Q58

124. 2.1.21 Tropical Rainforests Tropical rainforests are among the oldest and most stable ecosystems on Earth. They are incredibly resilient due to their high biodiversity and complex trophic interactions. https://www.bbc.co.uk/bitesize/guides/zwy7sg8/revision/5

125. 2.1.21 Tropical Rainforests Processes: Intense photosynthetic activity, rapid nutrient cycling due to warm temperatures and moist conditions, and diverse food web interactions. Outputs: High levels of oxygen production, heat energy from dense vegetation, and continuous leaf litter contributing to soil nutrient content.. https://www.bbc.co.uk/bitesize/guides/zwy7sg8/revision/5 Inputs: High levels of rainfall, abundant sunlight, and a rich supply of decomposed organic material.

126. 2.1.21 Resilience and Disturbances: Factors such as deforestation, climate change, and pollution can disrupt the balance of these systems. https://www.bbc.co.uk/bitesize/guides/zwy7sg8/revision/5 While ecosystems like tropical rainforests have shown great longevity, they are not immune to disturbances.

127. The r esilience of a system, ecological or social, refers to its tendency to avoid such tipping points and maintain stability Resilience refers to the ability of a system to return to its initial state after a disturbance. . 2.1.21 Resilience and Disturbances:

128. 2.1.22 Tipping Points Human activities significantly influence ecosystems, often pushing them towards critical thresholds or tipping points that lead to irreversible changes and the establishment of new ecological equilibriums.

129. 2.1.21 Tipping Point Identifying and understanding tipping points is crucial for ecosystem management and conservation Draw and label this graph on Q61 A tipping point is a threshold at which a system undergoes a rapid and irreversible change

130. 2.1.22 Direct Human Impacts on Biodiversity Overharvesting: T his refers to the unsustainable extraction of resources, leading to significant biodiversity loss. For instance, overfishing specific fish species can disrupt aquatic food chains and decrease marine biodiversity, undermining the health of marine ecosystems . Poaching and Illegal Wildlife Trade: These illegal activities pose severe threats to wildlife. Examples include the poaching of elephants for ivory and tigers for their body parts, as well as the capture of wild animals for the exotic pet trade. These actions can drastically reduce wildlife populations and disrupt ecological balances.

131. 2.1.22 Indirect Human Impacts on Biodiversity Habitat Loss Due to Land Use Changes: Converting natural landscapes into agricultural, urban, or industrial areas results in significant habitat loss. This reduces living space for native species, often leading to decreased biodiversity and disrupted ecological functions. Climate Change: Rising global CO2 emissions warm the planet and alter abiotic environmental conditions, threatening habitats and shifting geographic ranges of species, sometimes causing local extinctions. Pollution: Industrial and agricultural activities release pollutants into the air, water, and soil, degrading ecosystems. Contaminants like pesticides, plastics, and heavy metals harm wildlife and can reduce species populations. Invasive Species: Introducing non-native species to new environments can result in invasive outbreaks. These species often lack natural predators, allowing them to thrive unchecked, outcompete native species, and destabilize ecosystems.

132. 2.1.22 Deforestation of Amazon Rainforest

133. 2.1.22 Deforestation of Amazon Rainforest Process of Change: Plays a crucial role in regulating the global climate. It produces significant amounts of water vapor through transpiration, which contributes to regional and global precipitation patterns. Impact of Human Activity: Large-scale deforestation disrupts this cycle by reducing the forest's capacity for transpiration. This not only diminishes local rainfall but also affects atmospheric conditions and climate patterns far beyond the Amazon. Reduced rainfall can lead to further forest loss, creating a feedback loop that threatens the survival of the forest and its myriad ecological functions. New Equilibrium: The reduction in forest cover can lead to a tipping point where the rainforest may irreversibly transform into a savannah-like ecosystem, drastically different in biodiversity, structure, and function.

134. 2.1.22 Activity Q 67 Visit the Resilience Alliance database (http://www.resalliance.org/tdb-database) Browse the list of examples. Pay attention to the "Alternate Regimes" Design a diagram that includes arrows showing a positive feedback loop.

135. https://ib.bioninja.com.au/options/option-c-ecology-and-conser/c1-species-and-communities/keystone-species.html Keystone species: species that are crucial to the maintenance of their ecosystem Vital in determining the nature and structure of the entire ecosystem 2.1.23 Keystone species

136. Define keystone species. List two examples of a keystone species. Describe why they are classified as a keystone species Q 71 2.1.23 Keystone species

137. 2.1.23 Consequences of Losing Keystone species Trophic Cascades: The removal of a keystone predator can lead to an increase in prey populations, which may cause overgrazing and subsequent ecological degradation. For example, the absence of wolves can lead to an overabundance of deer, which may severely impact forest undergrowth and biodiversity. Habitat Changes: The disappearance of key herbivores like elephants might allow dense thickets to develop, which can alter fire regimes and reduce grassland areas, thereby affecting the entire savannah ecosystem. Biodiversity Loss: The extinction or reduction of a keystone species often leads to decreased ecosystem diversity. Their pivotal roles in the food web, habitat formation, and population control are vital for supporting a range of other species

138. 2.1.23 Consequences of Losing Keystone species

139. 2.1.23 Activity - Q 72 Research a keystone species that interests you identify its role in the ecosystem describe the specific interactions it has with other species explain the consequences of its removal or decline

140. Human Interactions

141. 2.1.24 Planetary Boundaries Model The Planetary Boundaries model provides a framework to understand and quantify the limits within which humanity can safely operate without causing irreversible environmental damage. ttps://www.stockholmresilience.org/research/planetary-boundaries.htm One of the critical components of this model is biosphere integrity, which has been significantly compromised by human activities.

142. 2.1.24 Planetary Boundaries Model Watch the video and answer Q76

143. 2.1.24 Overview of Biosphere Integrity Biosphere integrity encompasses the health and stability of species populations, the genetic diversity they contain, and the ecosystems' ability to function effectively. It is vital for sustaining life-supporting systems on Earth. Recent studies and environmental assessments indicate that the planetary boundary for biosphere integrity has been crossed. This breach is primarily due to human-induced pressures such as habitat destruction, pollution, overexploitation, and the introduction of invasive species.

144. 2.1.24 Impact on Ecosystems and Species Diversity Species Extinction: Extinction rates far exceed natural levels, leading to a drastic reduction in biodiversity. For example, it's estimated that about 70% of vertebrate populations have disappeared since 1973. Insect Population Decline: Insects are declining at a rate of approximately 2% per year, which is concerning due to their essential roles in pollination, nutrient cycling, and forming the base of many food webs. Impact on Ecosystems: The ongoing loss of biodiversity diminishes ecosystem resilience, increasing their susceptibility to additional stressors such as climate change. This threatens the stability and functionality of ecosystems worldwide.

145. 2.1.24 Conservation and Restoration Efforts Monitoring and Mitigation: Continual monitoring of human impacts on ecosystems is essential. Implementing conservation strategies that include protecting habitats, enforcing wildlife laws, and promoting sustainable resource use is critical for reversing detrimental trends. Restoration Efforts: Projects aimed at ecosystem restoration, such as reforestation, wetlands restoration, and reintroducing native species, are vital. These efforts help reestablish ecological networks and enhance biodiversity, ultimately boosting the resilience of ecosystems.

146. 2.1.25 Strategies to Avoid Critical Tipping Points Habitat Conservation: Taking proactive steps to conserve habitats is vital, involving the creation of protected areas, restoration of degraded habitats, and adoption of sustainable land-use practices to reduce environmental impact. Biodiversity Preservation : Preserving biodiversity is crucial for ecosystem resilience and adaptability. This includes supporting species richness and genetic diversity across populations. Pollution Control: Minimizing pollution is essential for the health and stability of ecosystems. Implementing effective waste management strategies, reducing hazardous substances, and employing cleaner production methods are key actions to reduce the ecological impact of human activities

147. 2.1.25 Strategies to avoid critical tipping points Regeneration Strategies: Regeneration efforts actively restore and enhance ecosystem functions in degraded areas, promoting biodiversity and resource storages. Techniques include rewilding landscapes, afforestation, wetland revival, and soil improvement through composting and other methods.

148. 2.1.25 Regeneration Strategies: Marine Reserves: Designating areas of the ocean where fishing and other extractive activities are restricted can help replenish fish stocks and protect coral reef ecosystems, which are vital for marine biodiversity. Forest Conservation Programs: Programs that promote sustainable forestry and prevent deforestation can maintain forest cover, which is essential for regulating climate, housing diverse species, and providing livelihoods for local communities.

149. 2.1.25 Activity - Q75 Select a regeneration strategy such as rewilding, afforestation, wetland revival, or soil improvement through composting Evaluate whether the strategy has led to a measurable increase in species diversity and genetic diversity within the ecosystem. Assess the extent to which essential ecosystem functions such as nutrient cycling, water filtration, and carbon sequestration have been restored or enhanced. Analyze whether the economic benefits, such as increased tourism, improved water quality, or carbon credits, justify the initial investment. Assess how the strategy affects local populations.

150. 2.1.25 Activity - Q75 Reintroduction of wolves in Yellowstone National Park, USA The Green Great Wall or Three-North Shelter Forest Program The restoration of the Mesopotamian Marshes The use of biochar and compost in degraded lands in the Amazon Rainforest Restoration of mangrove forests in Southeast Asia London or New York where natural habitats are restored within urban settings to increase biodiversity and provide green spaces for residents Restoring native prairies in the Midwest of the United States,

151. HL ONLY

152. HL 2.1.26 Cladogram Cladistics is a method of classification that not only maps out the evolutionary lineage of organisms but also enhances our understanding of how species evolve over time. This approach focuses on the relationships within a clade, a group of organisms that includes an ancestor and all its descendants, representing a single branch on the tree of life. https://www.deviantart.com/akimeterasu/art/Plantimal-Ecology-Vagaprales-Cladogram-910118838

153. HL 2.1.26 Cladogram

154. HL 2.1.26 Cladogram A cladogram not only illustrates evolutionary relations and common ancestors, but it also helps taxonomists to test the hypothesis of adaptation phenomenon by showing the: origin of the characteristics, disappearance and formation of characteristics, direction of change of characteristics, and relative frequency of the change

155. HL 2.1.26 Benefits of Cladistic Classification Improved Accuracy: Cladistics offers a more precise depiction of evolutionary relationships by focusing on descent from common ancestors, rather than just grouping species based on superficial similarities. Uncovering True Lineages: Advances in genetics and biochemistry have refined cladistic analyses, leading to the correction of misclassifications in traditional systems, such as the reclassification of the red panda. Detailed Evolutionary Insights: Cladograms provide detailed insights into evolutionary changes, tracing the origins, modifications, and potential extinctions of traits within lineages, enhancing our understanding of adaptive changes across time.

156. HL 2.1.26 Activity - Q 78 Research the evolutionary background of their assigned organisms, focusing on key traits and evolutionary milestones. Drawing the most recent common ancestor at the base of the cladogram. Add branches for each organism, positioning according to evolutionary divergence. Remember, organisms that share recent common ancestors should be closer together. Label each branch with the name of the organism.

157. HL 2.1.26 Activity - Q 78 Organisms to choose from Chimpanzee (Pan troglodytes) - Closest living relative to humans, useful for comparing primate evolution. Elephant (Loxodonta africana) - To illustrate the evolution of large mammals and complex social structures. Crocodile (Crocodylus niloticus) - Represents reptilian lineage with ancient evolutionary roots. Peregrine Falcon (Falco peregrinus) - To show avian adaptations and the evolution of flight. Axolotl (Ambystoma mexicanum) - A unique example of neoteny where the juvenile features are retained in adulthood. Coelacanth (Latimeria chalumnae) - A "living fossil" to discuss organisms that have changed little over millions of years. Giant Sequoia (Sequoiadendron giganteum) - To represent plant evolution and longevity. Australian Lungfish (Neoceratodus forsteri) - To explore the evolution of fish and their transition towards terrestrial living. Honeybee (Apis mellifera) - To discuss the evolution of insects and social behavior.

158. HL 2.1.27 Difficulties In Classifying Organisms The traditional taxa system was based on characteristics of organisms. Now that we have biochemical and nucleic acid databases, we are finding organisms that are not classified correctly

159. HL 2.1.27 Difficulties In Classifying Organisms Traditional classification systems were indeed based on physical characteristics, such as morphology, anatomy, and behaviour. However, these systems have limitations, as they do not always reflect the evolutionary relationships between organisms. Birds and bats both have wings and can fly, but they are not closely related

160. HL 2.1.27 Impact of Molecular Biology DNA Sequencing: The advent of molecular biology techniques has provided deeper insights into the genetic makeup of organisms. These techniques have uncovered numerous instances where the traditional taxonomic categories do not align with the organisms' evolutionary histories. Phylogenetic Classification: Scientists increasingly rely on phylogenetics, which uses genetic information to reconstruct the evolutionary relationships (phylogenies) that more accurately reflect how species diverged from common ancestors.

161. HL 2.1.27 Impact of Molecular Biology

162. 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) HL 2.1.28 Fundamental and Realized Niche

163. Watch the video and take notes on the key points presented. Q79 HL 2.1.28 Fundamental and Realized Niche

164. Background: Joseph Connell's classic study on barnacles demonstrated the distinction between fundamental and realized niches. He observed two barnacle species, Chthamalus stellatus and Balanus balanoides, on a rocky shore. Findings: Chthamalus stellatus could survive higher on the rocks beyond the reach of the tides—its fundamental niche. However, it primarily resides just above Balanus balanoides because of competitive exclusion—its realized niche . HL 2.1.28 Joseph Connell’s Barnacles

165. HL 2.1.28 Joseph Connell’s Barnacles Watch the video and complete Q80

166. Background: The study of brown anoles (Anolis sagrei) and green anoles (Anolis carolinensis) in Florida illustrates niche partitioning as a response to interspecific competition. HL 2.1.28 Brown and Green Anoles Interactions: Initially, both anole species competed for similar resources. Over time, green anoles, primarily arboreal (tree-dwelling), moved higher into the trees, whereas brown anoles, being more ground-dwelling, dominated the lower vegetation and ground areas. Outcome: This adjustment shows the shift from their fundamental niches to realized niches due to competitive pressures, allowing both species to coexist by reducing direct competition

167. HL 2.1.28 Brown and Green Anoles Watch the video and answer Q81

168. Reference your workbook question 83 Read the background information. Underline or highlight key information related to fundamental and realized niches. Produce a graphical summary of an example from one of the resources provided. Remember to use annotations which will aid your understanding HL 2.1.28 Activity - Q83

169. HL 2.1.29 Reproductive Behaviour ​Life cycles and reproductive behaviors vary significantly across species, influenced by their environmental contexts and evolutionary adaptations. exemplify how species have adapted their life cycles to thrive under different ecological conditions and successional stages. r-strategists K-strategists

170. HL 2.1.29 Reproductive Behaviour

171. Characterized by their ability to r eproduce quickly and in large numbers. Have short lifespans, rapid maturation, and produce many offspring with little to no parental care. Maximize reproductive success in contexts where mortality rates are high and environmental conditions are highly variable. Example: Many insects and annual plants. They can quickly colonize a disturbed area, such as a field left fallow or an area cleared by fire, using the available resources to produce a new generation before conditions change HL 2.1.29 r-Strategy Organisms

172. Adapted to stable environments where resources are more predictable but competition is higher. Typically produce fewer offspring , but invest significantly in each, increasing the likelihood of each offspring surviving to adulthood. Longer lifespans , s lower development , and often engage in complex parental care. Example: Elephants and humans, produce few offspring but providing extensive care and teaching, which prepares each for a higher chance of survival in a competitive world. HL 2.1.29 K-Strategy Organisms

173. HL 2.1.29 Reproductive Behaviour - Q84

174. HL 2.1.29 Survivorship Curve Survivorship curves are graphs that show the proportion of a population that survives from one age to the next

175. HL 2.1.30 Human Impact on Ecosystems ​Human activities profoundly influence the natural world, affecting species' classifications, niche requirements, and life cycles.

176. HL 2.1.30 Human Impact on Life Cycles Warmer springs can lead to earlier flowering in plants. This change, while subtle, can cascade through the ecosystem, affecting the life cycles of dependent species such as pollinators like bees and butterflies. Rising temperatures can alter the phenology (timing of life cycle events) of many species.

177. HL 2.1.30 Disruption of Synchronized Life Cycles Many species have life cycles that are intricately synchronized with those of other species and the seasonal cycles of their environments. Animals that rely on specific plant species for food during certain life stages may find that these food sources are no longer available when needed. Example: In aquatic environments, temperature changes affect the breeding cycles of fish. Warmer water can accelerate development stages, leading to earlier spawning seasons. This change may not align with the hatching times of aquatic insects, a crucial food source for juvenile fish, impacting survival rates and population dynamics

178. HL 2.1.30 Human Impact on Small Mammals Small mammals are particularly sensitive to changes in climate because their survival and reproductive success are closely tied to environmental conditions. Habitat Changes: may shift in altitude or latitude. Food Availability: seasonal cycles for food resources like seeds and insects. Altered Hibernation and Breeding Cycles : leads to energy deficits and lower survival rates. If breeding seasons shift due to temperature changes but do not align with food availability, it can affect the survival of offspring.

179. HL 2.1.30 Human Impact on Small Mammals

180. HL 2.1.30 Activity - Q 85 Research and describe the complete life cycle of your chosen species, emphasizing each stage from birth to reproduction. Identify specific human activities that impact the life cycle stages of the species. This should include both direct impacts (like habitat destruction for urban development affecting nesting sites) and indirect impacts (like climate change altering migration patterns).

181. HL 2.1.30 Activity - Q 85 Monarch Butterfly: Coral Reefs: Polar Bears: Frogs and Other Amphibians: Bees: Atlantic Salmon: Elephants: Bats: