The Distribution of Living Things
Even in some habitat where a particular species, it is not likely that it will be found absolutely everywhere. This might be because of abiotic factors, and also biotic ones (such as competition, predation etc.). Before we can start looking for this we need to look at the distribution pattern found. On shores there is an obvious pattern of bands, called zonation. An example of this can be seen here.
When we suspect such a pattern, it is reasonable to use a technique called a TRANSECT to investigate it.
In the LINE TRANSECT a line is laid across the bands or zones, like this:
The white line is the LINE, species are recorded at set intervals along the line, just where they touch it. This gives a QUICK idea of distribution but gives no idea of abundance.
A belt transect takes a bit longer, but gives both DISTRIBUTION and ABUNDANCE. Click here for more details.