How do scientists proclaim an ecosystem like the Western Ghats as an ‘biodiversity hotspot’ and push for its conservation? They do so by ‘ecological sampling’, a technique used to find diversity and abundance of animals and plants in a habitat. They collect samples of plants and animals from different locations within an area and extrapolate the possible biodiversity that exists in the area. Since it is physically laborious to survey every millimetre square of land or millimetre cube of water in a selected area, samples are generally taken in the form of square quadrats, from which the number and density of species are recorded.
Different kinds of habitats require different kinds of sampling techniques. Random sampling, for example, is used when the selected area is quite large and uniform. Here, samples are selected randomly from different locations, so that all species have an equal chance of being recorded. Systematic sampling is used when the habitat is non-uniform and to measure how the vegetation or the kind of animals found, changes gradually over a certain distance. Transects - lines made across an area in the selected habitat – are used to record the number and abundance of species along the line. In stratified sampling, certain areas within a habitat drastically differ from the major portion of the habitat and hence, need to be sampled separately.
Ecological sampling lays the groundwork for most research in wildlife biology, ecology and various other fields. It is a measure that points out direction for conservation and helps us understand the world around us.