2.3 Measuring Biotic Components

1. 2.3 Measuring Biotic Components

2. What is classification? • Science of grouping organisms based on their physical characteristics.

3. What characteristics do we use? • Structures (morphology) • Functions (physiology) • Biochemistry • Genetics

4. Why do we classify? • Identify organisms • Compare organisms • Identify relationships among organisms • Communicate with others (universal language) • Identify evolutionary relationships

5. 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.

6. From Aristotle to Linneaus • Aristotle (Greek philosopher) • (384-322 B.C) • First System of Classification • 1. Plants • Based on stem type • 2. Animals • Land, air or water

7. From Aristotle to Linneaus • CarolusLinneaus (Sweedish botanist) • (1707-1778) • Came up with modern classification system • Used binomial nomenclature (2 word naming system) • This two word name is called a scientific name • Composed of the genus name followed by the species name

8. Scientific Names • Either written in italics or underlined • Genus is always capitalized and species is always lowercase • Based on Latin • Examples: • Cat: Felix domesticus • Mosquito: Colexpipens • Human: Homo sapien

9. Funny Scientific Names • Agra vation (a beetle) • Colon rectum (another beetle) • Bahumbugi (a snail) • Aha ha ( a wasp) • Lalapalusa (a wasp) • Leonardo davinci (a moth) • Abracadabra (a clam) • Gelaebaen, Gelaebelae, Gelae donut, Gelae fish, and Gelaerol (all types of fungus beetles) • Villa manillae, Piezakake and Reissaroni  (bee flies)

10. Dichotomous Keys • A series of yes/no questions about an organisms structure • Used to identify new and unknown organisms

11. Example of Dichotomous Key • 1a. Hair Present…………..Class Mammalia • 1b. Hair Absent……………Go to statement 2

12. Example of Dichotomous Key • 2a. Feathers present…………..Class Aves • 2b. Feathers absent…………….Go to statement 3 • 3a. Jaw Present…………………..Go to statement 4 • 3b. Jaw Absent……………………Class Agnatha

13. Example of Dichotomous Key • 4a. Paired fins present……………Go to 5 • 4b. Paired fins absent…………….Go to 6

14. Example of Dichotomous Key • 6a. Skin scales present………………Class Reptilia • 6b. Skin scales absent……………….Class Ampibia

15. Estimating Populations of Organisms • We estimate populations because it would take way too long to count every living thing in a given ecosystem. • We can estimate populations of plants or animals • Random Sampling: All organisms must have an equal chance of being captured.

16. Estimating Populations of Animals • Lincoln index (capture-mark-release-recapture) n1 x n2 N = n3 • N = Total number of population • n1 = Number of animals first (mark all of them) • n2= Number of animals captured in second sample • n3= Number of marked animals in second sample Ex. 40 mice were caught, marked (tail tattoo) and released. Later, 10 mice were recaptured, 4 of which had tattoo marks.

17. Lincoln Index

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

19. Estimating Populations of Plants • Quadrat Estimation • Population Density- The number of plants within the given area of the quadrat (m2) • Percentage Coverage- How much of the area of a quadrat is covered by plants? • Frequency- How often does a plant occur in each quadrat? • Acacia senegalensis was present in 47 of 92 quadrats, for a frequency of 51%

20. Calculate Population Density What is the population density of species x ? What is the population density of species Y? What is the population density of species Z? Quadrat 1= 0.5m2

21. Calculate Percentage Coverage What is the percentage of plant coverage in this quadrat? Quadrat 1= 0.5m2

22. Percentage Frequency Quadrat 1 What is the frequency of species X? What about species V? Quadrat 2 Quadrat 3

23. Other Methods of Estimation(Plants) • Sampling – Take a sample from one area and assume the organisms are evenly spread out through the area. • Biomass (dry weight) of living tissue • We use dry weight because water is non-living and needs to be excluded • Ex. 10 ferns were found in a 100m2 area. How many ferns would be in 1000m2 field in the same ecosystem?

24. What is diversity? • Diversity is the variety of life • Diversity is a combination of two components • Evenness: The number individuals of each species present in a sample • Richness: The total number of different species in a sample

25. How Can We Know Diversity? Use the Simpsons diversity index below D = ____________N (N-1)_______________ n1(n1−1) + n2(n2 −1) + n3(n3 −1) +…nk(nk −1) D = Diversity N = Total number of organisms of all species n = number of individuals of a particular species ***The higher the D value the more diverse the sample is!!!!!

26. Example Data Calculations