In school, we're learning about transects, quadrats and capturing and releasing animals. I was just wondering, do biologists really use these sorts of sampling methods out in nature?

Hi Joon,

the answer is Yes.  The methods seem quite archaic when you are throwing quadrats over your shoulder on the playing field, and I suppose they are, but they are effective at producing a random sample method in the field.  You don't often see people throwing quadrats round in 'real' field situations.  Often the sampling sites are generated randomly by a computer, after an area has been divided into squares in a grid.  It is important that sampling is done randomly, because humans are naturally biased towards things that will keep them entertained (lots of work over there.  I can see 50 mole hills/ant nests/termite mounds!  That will keep me busy), or inclined to 'skive off' (the opposite).  By randomly sampling, we know that we are going to get a reasonable idea of number and distribution of the plants, or animals, that we are interested in understanding. 
Transects may be used for assessing the distribution of organism at different heights of a beach, from the top to the foreshore.  If you are looking at communities on the beach, you may pick a line transect, and then take samples at points along the line at each point where the height of the beach, above sea level, drops by 50cm (or whatever number you choose).

If you are interested in taking plankton trawls off of a coast, you may use a certain line of longitude as your transect, to see how latitude (for example) affects plankton distribution.

What seems like a mundane task on the school sports field looking for insects, really does have applications in the study of biology and ecology outside of school.

Last edited by Neil Gostling (23rd Feb 2007 17:52:27)