1. Introduction to Ecology cont’d

2. Introduction to Ecology How do you know you are talking to a real ecologist? They always answer any question the same way. Rob Colwell

3. Introduction to Ecology How do you know you are talking to a real ecologist? They always answer any question the same way. “Well it depends…” Rob Colwell

4. Ecology is: A science of dependency A probabilistic science

5. Intermediate Number Systems

6. The first ecologists?

7. Two Founders of Ecology Ernst Haeckel Eugene Warming

8. Definitions of Ecology Haeckel – 1870 – By ecology we mean the body of knowledge concerning the economy of nature – the investigation of the total relations of the animal both to its inorganic and organic environment. Tansley – 1904 – (Ecology is) Those relations of plants, with their surroundings and with one another, which depend directly upon differences of habitat among plants. Elton – 1927 – Ecology is the new name for a very old subject. It simply means scientific natural history.

9. Definitions of Ecology cont’d Andrewartha – 1961 – Ecology is the scientific study of the distribution and abundance of organisms. Krebs – 1972, 2008 – Ecology is the scientific study of the interactions that determine the distribution and abundance of organisms. Townsend et al. 2003 – Ecology is the scientific study of the distribution and abundance of organisms and the interactions that determine distribution and abundance.

10. We study these interactions via: Descriptive studies Modeling – verbal, graphical or mathematical Experiments in nature

11. The Fundamental Equation of Ecology – Harper 1977 Δ N = B – D + I – E Change in Number = Births – Deaths + Immigration - Emigration John L. Harper – 1925-2009

12. Some Definitions of Terms environment - biotic and abiotic factors that influence organisms organism - individual living thing population - many individuals of one species living close enough to each other to potentially interbreed community - all interacting populations in a particular habitat - includes plants, animals, decomposer microbes - pond or forest community. - in practice often used when 2 or more species discussed

13. Some Definitions of Terms ecosystem - community plus abiotic factors - nutrients, water, soil, climate, etc. - pond ecosystem habitat - place where microbe, plant or animal lives biosphere - the earth and all its ecological systems autecology - relation of individual organism to environment synecology - relation of populations or species to other populations or species

15. How to study ecology?

17. Initial Observation Hypothesis reasoning? Experiment Observation/ Data Analysis Interpretation Hypothesis not Supported New Hypothesis New Experiment New Observation Final Hypothesis Supported Theory Scientific method is a repetitive process that leads to the building of theories

18. Creosote and sage brush desert

19. Diagram of desert plant root growth

20. Statistics - a powerful tool for analyzing data 1. Descriptive Statistics - provide an overview of the attributes of a data set. These include measurements of central tendency (frequency histograms, mean, median, & mode) and dispersion (range, variance & standard deviation) 2. Inferential Statistics - provide measures of how well your data support your hypothesis and if your data are generalizable beyond what was tested (significance tests)

21. Differences Between Means Asks whether samples come from populations with different means Null HypothesisAlternative Hypothesis A Y BCA Y BC

22. Observational Studies pubs.usgs.gov/circ/circ1209/studyunit_design.htm

23. Watering Hole showing Piosphere Piosphere is an area of land degraded by many animals gathering around a watering hole

24. Model of Piosphere

25. Lab Experiments

26. Field Experiments Pelvetiopsis

27. Rothamsted, England – Broadbalk Wheat Experiment

28. Rothamsted, England – Park Grass Experiment

29. Natural snapshot experiment Succession following avalanches at different times

30. Natural trajectory experiment Eruption of Krakatau – 1883