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)
( B.C)
First System of Classification
1. Plants
Based on stem type
2. Animals
Land, air or water

7. From Aristotle to Linneaus
Carolus Linneaus (Sweedish botanist)
( )
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: Colex pipens
Human: Homo sapien

9. Funny Scientific Names
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)

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 X W z Y

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

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

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
Abundance of Organism
Ecosystem A
Ecosystem B
species 1 3 5
species 2 7 4
species 3 26 12
species 4 9
species 5
Diversity
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