Study of population density and frequency of different plant populations, by quadrat method

 

Practical Notebook Biology Standard XII

Biology 

Answeres

Practical Notebook
Standard XII

Class-12th

science

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8. Study of population density and frequency of different plant populations, by quadrat method. 

 Aim: 

To study population density and frequency of plant population by quadrat method.  

Principle: 

1. All the different types of individual plants growing at a particular space or geographical area at a particular time, form (constitutes) the plant population of that area.  
2.  It changes from time to time and may increase or decrease due to many different factors.  
3. The number of individuals of a species present per unit area at a given time is called population density.  6. Population density = 4. 
4. The population density (D) can be calculated as D = N / S.  where N Number of individuals of a species and S- Units of space or area (no. of quadrats).  MS 
5. The population density can be determined by marking quadrats of suitable size and recording the number of individuals of each species occurring in the quadrat.  8. Abundance (A) = 7. Percentage frequency (F) = 7 Total number of individuals of a species in all the quadrats studied (N) Total no.  of quadrats studied (S) Total number of quadrats in which species occurred Total no.  of quadrats studied Total number of individuals of species No.  of quadrats in which species occurred Requirements: Meter seale, string, nails, paper, pencil, etc.  38 x 100 

Procedure:

1. With the help of nails and string prepare four quadrants of suitable size at a number of places randomly.  (A quadrat is a squarish geographical area of ​​the suitable size used as a unit for the study of vegetation) 
2.  Count the number of each plant species present in every quadrant.  
3.  Record data in the observation table and calculate the population density and percentage frequency of different species by using the formula given above.  Fl