2.3 measuring biotic components
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2.3 Measuring Biotic Components . What is classification?. Science of grouping organisms based on their physical characteristics. What characteristics do we use?. Structures (morphology) Functions (physiology) Biochemistry Genetics. Why do we classify?. Identify organisms - PowerPoint PPT PresentationTRANSCRIPT
2.3 Measuring Biotic Components
What is classification?
Science of grouping organisms based on their physical characteristics.
What characteristics do we use?
Structures (morphology)Functions (physiology)BiochemistryGenetics
Why do we classify?
Identify organismsCompare organismsIdentify relationships among organismsCommunicate with others (universal
language)Identify evolutionary relationships
Why do we classify?What am I?FireflyLightning bugGlow FlyBlinkie Golden SparklerMoon bugGlühwürmchenLuciérnagaLucioleWe all have different names for the same
organism…this is a problem for communication.
Same or different?
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
From Aristotle to Linneaus
Carolus Linneaus (Swedish 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
Scientific Names
Either written in italics or underlinedGenus is always capitalized and species is
always lowercaseBased on Latin Examples:
Cat: Felix domesticus Mosquito: Colex pipens Human: Homo sapien
Funny Scientific NamesAgra 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)
Dichotomous Keys A series of yes/no questions about an organisms
structure Used to identify new and unknown organisms
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.
Estimating Populations of Animals
Lincoln index (capture-mark-release-recapture)n1 x n2N = 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.
Lincoln Index
Lincoln Index Practice Problem
An ornithologist captured 450 finches, marked them with an ankle band and released them. One week later she recaptured 237 finches, 50 of which had ankle bands. What is the total finch population?
Lincoln Index Assumptions
1. The marked animals are not affected (neither in behavior nor life expectancy).
2. The marked animals are completely mixed in the population.
3. The probability of capturing a marked animal is the same as that of capturing any member of the population.
4. Sampling time intervals must be small in relation to the total time of experiment of organisms life span.
5. The population is closed (no immigration and emigration)
6. No births or deaths in the period between sampling.
Estimating Populations of PlantsQuadrat 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?
Percentage Frequency- How often does a plant occur in each quadrat? Acacia senegalensis was present in 47 of 92
quadrats, for a frequency of 51%
Calculate Population Density
X X X W W
W X X W X
W X X X X
W X W X W
W Z W W Y
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
Calculate Percentage Coverage
X X WW X X W X
W X X X
W X W
X W Y
What is the percentage of plant coverage in this quadrat?
Quadrat 1= 1m2
Percentage Frequency
X X X W WW X X W XW X X X XW X W X WW Z W W Y
What is the frequency of species X?
What about species V?
Z Z Z W WW Z Z Z ZW Z Z W ZW X W Z WW Z W W Y
Quadrat 2 Quadrat 3
X X X W WW X X W XW X X X XW X V X WW Z W W Y
Quadrat 1
Estimating Biomass of Tropic Levels
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. 1500g of ferns were sampled in a 100m2 area. How many ferns would be in 1000m2 field in the same ecosystem?
What is diversity?
Diversity is the variety of lifeDiversity 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
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 = DiversityN = Total number of organisms of all speciesn = number of individuals of a particular species***The higher the D value the more diverse the sample is!!!!!
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 7
species 5 7 0
Diversity 3.27
Sample CalculationNumber of Organisms
Ecosystem B
species 1 5
species 2 4
species 3 12
species 4 7
species 5 0
Diversity