1. Biodiversity in Ecosystems IB syllabus: 2.3.4, 2.3.5, 4.1.1 – 4.1.5

2. Syllabus Statements 2.3.4: Define the term diversity 2.3.5: Apply Simpson’s diversity index and outline its significance

3. Syllabus Statements 4.1.1: Define the terms biodiversity, genetic diversity, species diversity, habitat diversity 4.1.2: Outline the mechanism of natural selection as a possible driving force for speciation 4.1.3: State that isolation can lead to different species being produced that are unable to interbreed to yield fertile offspring 4.1.4: Explain how plate activity has influenced evolution and biodiversity 4.1.5: Explain the relationships among ecosystem stability, diversity, succession & habitat

4. vocabulary Biodiversity Diversity Diversity index Genetic Diversity Habitat diversity Isolation Plate Tectonics Species Diversity Speciation Species

5. Diversity A generic term for heterogeneity. The scientific meaning of diversity becomes clear from the context in which it is used; it may refer to heterogeneity of species, habitats or genes.

6. Species A group of organisms that can interbreed and produce fertile viable offspring

7. Kinds of Biodiversity 1.Biodiversity = the amount of biological or living diversity per unit area. It includes the concepts of species diversity, genetic diversity and habitat diversity 2.Genetic diversity = the range of genetic material present in a gene pool or population of a species 3.Species diversity = variety among species per unit area. Includes both the number of species present and their abundance. 4.Habitat diversity = The range of different habitats or number of ecological niches per unit area in an ecosystem, community or biome. Conservation of habitat diversity usually leads to conservation of species and genetic diversity

8. Each Species and Process… Is key to the overall function of earth In general Diversity = Stability Biodiversity is –Nature’s insurance policy against change –The source of all natural capital for human use –The way chemical materials are cycled and purified –The end result of millions of years of evolution and irreplaceable

9. Mexico Brazil Madagascar South Africa Australia Indonesia Philippines India China Ecuador Colombia Costa Rica Peru Venezuela Cameroon Zaire Ethiopia Myanmar Malaysia The 19 Most Biodiverse countries in the world. What is the Problem with this?

10. Polynesia and Micronesia island complex Mediterranean basin Caribbean Western Ghats and Sri Lanka Philippines Wallacea New Caledonia Tropical Andes Central Chile Brazillian Cerrado Caucasus Eastern Arc Mountains and coastal forests of Kenya and Tanzania Cape Floristic region of South Africa Succulent Karoo Madagascar/ Indian Ocean islands Southwest Australia New Zealand Polynesia and Micronesia island complex Indo- Burma Mountains of south central China Guinean forests of West Africa Brazil's Atlantic forests Sundaland Choco/Darien/ western Ecuador California Floristic Province Meso- american forests Biodiversity Hotspots need special consideration

11. Hotspots These areas need emergency conservation attention Especially rich in endemic plant and animal species (found nowhere else in the world) They cover on 1.4% of world land area Mostly tropical forests Contain 60% of identified terrestrial biodiversity 55% of all primates, 22% of all carnivores 1.1 billion people living in poverty near these sites $500 million annually would go far to ensure their preservation

12. Diversity includes 1.Richness: The number of species per sample is a measure of richness.  The more species present in a sample, the “richer” the sample. 2.Evenness: A measure of the relative abundance of the different species making up the richness of an area.

13. Which sample is more diverse? Flower SpeciesSample 1Sample 2 Daisy30020 Dandelion33549 Buttercup365931 Total1000 Which has a higher richness? Evenness?

14. Quantifiying this Diversity – Simpson’s Index D = N (N – 1) ∑ n (n – 1) Where D = diversity index N = total # of organisms of all species n = # of individuals of particular species

15. Now practice the simpson’s index SpeciesNumber (n)n (n – 1) Woodrush2 Holly seedlings8 Bramble1 Yorkshire Fog1 Sedge3 Total (N)

16. Now practice the simpson’s index SpeciesNumber (n)n (n – 1) Woodrush2 Holly seedlings8 Bramble1 Yorkshire Fog1 Sedge3 Total (N)15

17. Now practice the simpson’s index SpeciesNumber (n)n (n – 1) Woodrush22 Holly seedlings856 Bramble10 Yorkshire Fog10 Sedge36 Total (N)1564 15(14) / 64 =3.28

18. High values of “D” suggests a stable and ancient site A low value of “D” could suggest pollution, recent colonization, or agricultural management Index normally used in studies of vegetation but can be applied to comparisons of diversity of any species

19. How does diversity exist? Natural Selection = survival of the fittest Fitness = a measure of reproductive success If all individuals are variable And populations produce large numbers of offspring without increase in population size And resources are limited And traits are heritable Then those individuals who are best adapted to the environment will survive and pass on their genes Gradually the gene frequency in the population will represent more of these “fit” individuals

21. Formation of the earth’s early crust and atmosphere Small organic molecules form in the seas Large organic molecules (biopolymers) form in the seas First protocells form in the seas Single-cell prokaryotes form in the seas Single-cell eukaryotes form in the seas Variety of multicellular organisms form, first in the seas and later on land Chemical Evolution (1 billion years) Biological Evolution (3.7 billion years) © 2004 Brooks/Cole – Thomson Learning

22. Plants begin invading land Evolution and expansion of life First fossil record of animals Plants invade the land Age of reptiles Age of mammals Insects and amphibians invade the land Modern humans (Homo sapiens) appear about 2 seconds before midnight Recorded human history begins 1/4 second before midnight Origin of life (3.6–3.8 billion years ago) noon midnight

23. Natural Selection over Time Environmental Pressures select for some genotypes over others Alleles resulting in a beneficial trait will become more common Heritable traits that increase survival chances are called adaptations There are many niches or habitats and roles available in the environment As populations adapt they fill new niches and over time may develop into new species

26. Speciation Certain circumstances lead to the production of new species through natural selection Most common mechanism has 2 phases  geographic followed by reproductive isolation 1. Geographic isolation  groups of a population of the same species are isolated for long periods –A group may migrate in search of food to an area with different environmental conditions –Populations may be separated by a physical barrier (mountain range, river, road) –Catastrophic change by volcano eruption or earthquake –A few individuals carried away by wind or water to new area

27. Speciation 2 2.Reproductive Isolation  mutation and natural selection operate independently on the 2 populations to change allele frequencies = divergence If divergence continues long enough genetic differences may prohibit (1) interbreeding between populations and/or (2) production of viable, fertile offspring One species has become 2 through divergent evolution For most species this would take millions of years Difficult to document & prove this process

28. Early fox population Spreads northward and southward and separates Adapted to heat through lightweight fur and long ears, legs, and nose, which give off more heat. Adapted to cold through heavier fur, short ears, short legs, short nose. White fur matches snow for camouflage. Gray Fox Arctic Fox Different environmental conditions lead to different selective pressures and evolution into two different species. Southern population Northern population

29. Consequences of Plate Activity Speciation processes rely on physical separation of organisms Plate techtonics –can lead to separation of gene pools – mountain ranges form, faults separating land masses –Can link species and land areas e.g. land bridges

30. Consequences of Plate Activity II Plate techtonics generates new habitats –Island chains over hotspots – Hawaii –Mountain habitats – Himalayan mountains – also associated effects on surrounding areas –Hydrothermal vent communities –Changes climate on land masses – continents drift into new climate zones  e.g. antarctica was once covered by tropical rainforest now barren polar ice fields

32. 1. Succession effects Diversity Succession – gradual establishment or reestablishment of ecosystems over time Pioneer species  Climax species –Low diversity at first, few species can tolerate harsh conditions (r selected species) –Most diverse in middle of succession, slower growing species start to fill in –Low diversity at the end, climax species often strongest competitors (K selected species) Diversity is a function of disturbance  intermediate disturbance hypothesis

33. Time Small herbs and shrubs Heath mat Jack pine, black spruce, and aspen Balsam fir, paper birch, and white spruce climax community Exposed rocks Lichens and mosses

34. 1000 Percentage disturbance Species diversity

35. 2. Habitat diversity influences species & genetic diversity More complex areas (more diverse habitats) often have higher species & genetic diversity Ex. Tropical rainforest & Coral reef In both cases, high degree of structural / spatial complexity Promotes coexistence by niche partitioning & diversification

36. Producer to primary consumer Primary to secondary consumer Secondary to higher-level consumer All producers and consumers to decomposers Fungi Bacteria Bromeliad Ants Tree frog Green tree snake Katydid Climbing monstera palm Squirrel monkeys Blue and gold macaw Harpy eagle Ocelot Slaty-tailed trogon Slaty-tailed trogon

37. Harpy eagle Toco toucan Wooly opossum Brazilian tapir Black-crowned antpitta Shrub layer Canopy Emergent layer Understory Ground layer Ground layer 0 5 10 15 20 25 30 35 40 45 Height (meters)

38. Complex ecosystems with a variety of nutrient & energy pathways provides stability Energy is key to the function of all ecosystems Biogeochemical cycles recycle necessary materials through system More pathways for energy & matter = more stable Insurance against natural or human changes

39. Human activities Modify succession by adding disturbance Logging, Grazing, Burning – all prevent natural successional processes Fragmenting habitats by development Isolate populations  more likely to get diseases, succumb to local disturbances We simplify ecosystems  tall grass prairie converted to wheat farms  more vulnerable

40. Highway Cleared plots for grazing Cleared plots for agriculture

41. BromeliadOrchid Roads Logging Cash crops Cattle ranching Tree plantations Flooding from dams Mining Oil drilling Unsustainable peasant farming Primary Causes: Rapid population growth Exploitive government policies Poverty Exports to developed counties Failure to include ecological services in evaluating forest resources Toucan Scarletmacaw Golden lion marmoset Blue morpho butterfly Secondary Causes:

42. Any ecosystem’s capacity to survive change may depend on its diversity, resilience, and inertia