Biotic Factor of Environment

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Biotic factor of environment
Oct 16, 2012

* Biotic factors are organism or their product that directly or indirectly affect an organism. Measuring biotic components of the system
1. Lincoln index: (pg. 20) N= n1*n2m
* Ntotal population size
* n1number of animal capture on first time
* n2number of animal capture on second time
* mnumber of marked animal recapture
* Involves collecting sample from the population, marking them in some way releasing them back into the wild then re-sampling sometime later and counting how many marked individual you find in the second capture. 2. Quadrat (pg.31)

* Used for plants
* N= mean member per quadrat*total areaarea of each quadrat * Count the number of different species of quadrat. (1*1 meter) * Repeat it as many time as possible.
* If your sample area covers habitats which are different from each other (e.g. soil in valley is better) you need to take sets of sample from both areas. The line which is between two types of area is called transect. 3. Keys for species identification

* Once you have collected the organisms, you may want to find out what they are called. It needs to use a dichotomous key. * Dichotomous means ‘divided into two parts’. The identification is done in steps. In each steps two options are given based on different possible characteristic of the organism. You are looking at the outcome of each choice leads to another pair of question, until the organism has been identified. * Scientists put all living organism into categories. The science of placing organisms into categories on the bases of their observable characteristic is called taxonomy (classification). * Taxonomy hierarchy:

1. Kingdom - 5 animals, plants, fungi, prokaryotes, protoctists/ eukaryotes. 2. Phylum / phyla - vertebrates
3. Class - mammal, fish, bird, reptile, amphibian
4. Order
5. Family
6. Genus
7. Species
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