Why study biodiversity, ecology, and conservation biology? What is biodiversity

2. Why study biodiversity, ecology, and conservation biology? • What is biodiversity • How do biologists organize biodiversity? • Why is biodiversity important? • What is the “biodiversity crisis”? • How can we protect biodiversity?

4. Earth’s Biodiversity Biodiversity - The diversity of life on Earth -variety at all levels of biological organization Components of Biodiversity: • genetic diversity – genetic variation among populations or species • Species diversity – number of species within an area • Diversity among higher taxa– variation between genera, families, orders, etc • Ecosystem diversity – variation among ecosystems, communities, landscapes Are different groups of organisms equally diverse? Are equal parts of the world equally diverse?

5. How many species are there? • About 1.5 million species have been named • Estimated to be between 5 and 30 million species on Earth

7. How is biodiversity organized?

8. Regions and systems vary in biodiversity Variations among regions and ecosystems in species composition and species diversity Biodiversity hotspots: regions with very high biodiversity mainly in the tropics, also islands, some other areas Diverse ecosystems: tropical rainforests, coral reefs, islands Endemic species: found only in one place in the world, often on islands

9. Why is biodiversity so important? Economic value – resources, including food medicines and other helpful chemicals genes for better crops “opportunity costs” Utilitarian value – prevent erosion purify water recycle CO2 regulate climate recycle nutrients through decomposition collectively, “ecosystems services” Psychological value – direct or indirect enjoyment of nature Intrinsic value – independent of humans

10. What is the biodiversity crisis? Humans are causing extinctions at a tremendous rate. • 100 times faster than expected without human activity • Parallels or exceeds previous mass extinction events Why is the loss of biodiversity a crisis? • Economic value of biodiversity lost or threatened • “ecological services” lost or threatened • Ecosystems more vulnerable to further degradation

11. What is the biodiversity crisis? Humans are causing extinctions at a tremendous rate. • 100 times faster than expected without human activity • Parallels or exceeds previous mass extinction events Current rate of extinction is at least 100x background

12. What are the biggest threats to biodiversity? • habitat destruction and fragmentation

13. What are the biggest threats to biodiversity? • habitat destruction and fragmentation • Habitat modification

14. What are the biggest threats to biodiversity? • habitat destruction and fragmentation • Habitat modification • Introduced species

15. What are the biggest threats to biodiversity? • habitat destruction and fragmentation • Habitat modification • Introduced species • Overexplotation

16. What are the biggest threats to biodiversity? • habitat destruction and fragmentation • Habitat modification • Introduced species • Overexplotation

17. What is conservation biology? • The science of protecting and restoring biodiversity and ecological health An applied science Basic principlesGoals ecology maintain biological diversity evolutionary biologyand ecosystem health genetics physiology

18. What do conservation biologists do? Apply ecological and evolutionary principles • To understand biodiversity and ecosystem functioning • To understand threats to biodiversity and ecosystem health • Ultimately, to protect and restore biodiversity and ecosystem health What makes a healthy ecosystem? How can we protect and restore biodiversity and ecosystem health?

19. What makes a healthy ecosystem? • Intact structure and function Functional groups, e.g. pollinators Trophic Levels

20. What makes a healthy ecosystem? • Intact structure and function Keystone species

21. What makes a healthy ecosystem? • Intact structure and function Ecosystem services, e.g. water purification Nutrient cycling

22. What makes a healthy ecosystem? • Intact structure and function • Resiliency of ecosystems to stress Diversity

23. What makes a healthy ecosystem? • Intact structure and function • Resiliency of ecosystems to stress Complexity and functional redundancy

24. How do ecology and evolution inform conservation biology? • What is a species? • What determines whether a species die or evolve? • Where does genetic variation come from? • What determines whether populations grow or crash? • How can competing species coexist? • Why do ecosystems differ in biodiversity? • How do communities and ecosystems “work”? • What causes extinction?

25. Genetic Diversity: the total number of genetic characteristics of a specific species, subspecies, or group of species • The total base pair sequences in DNA, or • The total number of genes, active or not, or • The total number of active genes

26. Habitat Diversity: the different kinds of habitats in a given unit area

27. Species Diversity: has the 3 following qualities • Species richness – the total number of species • Species evenness – the relative abundance of species • Species dominance – the most abundant species

28. Sample A could be described as being the more diverse as it contains three species to sample B's two. But there is less chance in sample B than in sample A that two randomly chosen individuals will be of the same species.

29. Why are there so many species? It’s all about interactions!

30. 1 - Competition – competitive exclusion principle – “complete competitors cannot coexist” • Example is the grey squirrel/red squirrel history in Great Britain (invasive species)

31. Niche Importance: species that require the same resources can coexist by utilizing those resources under different environmental conditions (EX: flour beetles)

33. Habitat complexity allows complete (and almost complete) competitors to coexist because they can then avoid competing with each other • This becomes important in evaluating the significance of deliberate changes in habitats (often for human development purposes) as this habitat changes may impact ecological niches • Deforestation (changing the habitat) may reduce herbivores, therefore affecting the ecological niche of predators (the wolf, for example)

34. 2 – Symbiosis - species work together for mutual benefit • In humans, about 10% of a person’s weight is actually the weight of symbiotic organisms in the intestines (this is an example of physiological symbiosis)

35. Social/behavioral symbiosis – the difference between dogs and wolves • Plants depending on animals to spread seeds • Implications for biodiversity are that saving habitat and niche are often not enough, must save symbionts as well • In order to save a single species, often must save a group

36. 3 – Predation and Parasitism – these relationships are beneficial for one species and detrimental to another • Predation – one organism kills and eats another • Parasitism- one organism lives in or on another, depending on it for existence and often harming it • Both can influence biological diversity • A predator eating the most abundant prey species may make room for other prey species to flourish

38. Environmental Factors that Influence Diversity • Variation in diversity is a matter of latitude – greater diversity occurs at lower latitudes • Topographical factors (soil type, slope, elevation, aspect [facing sun or away], nearness to a drainage basin) affect the type and abundance of plants that will grow there • This in turn affects the type and abundance of animals that will live there

40. Factors that tend to increase diversity • A physically diverse habitat • Moderate amounts of disturbance (fire, storm water) • Small variation in environmental conditions (temperature, precipitation, etc) • High diversity at one trophic level increases diversity at other trophic levels • An environment highly modified by life (EX: a rich organic soil) • Middle stages of succession • Evolution

41. Factors that tend to decrease diversity • Environmental stress • Extreme environments • A severe limitation in the supply of an essential resource • Extreme amounts of disturbance • Recent introductions of exotic species • Geographic isolation