The Open Door Web Site : IB Biology : ICT in Biology : Transects and Calculators

Lay out the tape or string across the transition zone so that it is straight and taught. Tie it down at both ends. Be careful not to trample the vegetation beside the line.

Note the orientation of the line (north-south, east-west etc.) and the major features along the transect. Use a data table to record your results.

Starting at one end, lay your quadrat by the side of the line and identify the species of plant or animal present. Estimate their abundance using the scale given below:

Scale	Percentage Cover	Abundance Rating
Trace	<1%	Single individual
1	1 - 5%	Rare
2	6 - 25%	Occasional
3	26 - 50%	Frequent
4	51 - 75%	Abundant
5	76 - 100%	Dominant

Record each species and their abundance in the table. Repeat this every other metre along the transect (see diagram below). Add new species to the bottom of the list.

Record at the bottom of your table the abiotic factors measured every other metre along the transect: Measure these within are relative short space of time so that variations in the weather do not influence the readings too much.
You may collect your data using your calculator, the CBL2 interface and probes. The data will be stored in the calculator which can be downloaded later (see relevant instruction sheets).

Record the height profile of the transect using the ranging poles and the spirit level. Place the first pole at the beginning of the transect and the second pole at 1 metre. Using the spirit level, measure the difference in height of the two poles. See the diagram below.

Record an increase as a positive value and a decrease as a negative value. Where there is a sudden change in height place the poles at shorter intervals. On soft ground be sure not to push the poles into the soil, they should be gently resting on the ground.