Download presentation
Presentation is loading. Please wait.
Published bySheryl Ford Modified over 9 years ago
1
Quantitative Study of plants (and animals) of a sample area of the selected ecosystem Transfer Results to Diagrams Graphs Tables Histograms Other relevant mode Quantitative Study relates to the number of organisms present A Quadrat (used for quantitative studies of plants or sessile animals) is: A frame that forms a known area (often.5m x.5m =.25m2) Usually square shaped 2 types: (i) Frame quadrat or (ii) Point quadrat (gridded) Used to measure Frequency (i) or Percentage Cover (ii)
2
Frequency = The chance of finding a named organism within the sample area Percentage Cover = the area of ground occupied by aerial parts of a named plant within the sample area (expressed as a percentage of the total area) – used for ‘cover plants e.g. grass 1. Throw the frame quadrat (size must match survey area for accuracy) randomly in the sample area (safely? how? ) 2. Record the presence or absence of the named organism within each quadrat 3. Repeat for a number of throws (more throws, more accuracy) 4. Tabulate results 5. Calculate using formula below: (can be converted to a percentage by multiplying by 100) 1. Throw the point quadrat (size must match survey area for accuracy) randomly in the sample area (safely? how?) 2. Lower the needle at each of the 25 sampling point s - i.e. where wires cross 3. Record the number of hits at the sampling points – i.e. if plant touches the needle at one of the 25 cross points that represents 4% cover (so multiply ‘hits’ by 4) 4. Repeat for a number of throws (more throws, more accuracy) to get the average 5. Tabulate results 6. Calculate average percentage cover Using a FRAME quadrat Using a POINT quadrat
3
If percentage is required multiply frequency by 100 Frequency table
4
Chart/Graph of Frequency
6
Pie Chart of Percentage Cover
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.