Question

Suppose you were given the task of estimating the density of two plant species in a field. Based on the life histories of the two species, you expect that the spatial dispersion of one species is approximately uniform, whereas the other is likely to be clumped. How might your approach to estimating the density of these two species differ?

Answer 1

Ans- Here two terms are used in que species density and dispersion .Let usunderstand these terms.

Species density - is the number of individual plant in a species area or in a given area . Density is used for vegetation survey .it refers to the volume of individual plant.

Species distribution or dispersion- refers to the how individual in a space is distributed(spacing between plants) . For eg dispersion of seeeds on a land during sowing decides the pattern of growth , like less or far dense . And species distribution or plant distribution is affected by several factors like wind , soil , light or bold seeds , nutrients distribution etc.

For Uniform Species- in uniform species distribution sample can be selected randomly from a uniform plant population.And then the sum of counts we get or we can say ( mean) average collected from the sample be divided by the total area of the extent.

For Clumped - Clumped dispersion occurs due to uneven distribution or intensive distribution of mineral and nutrition in an area.In this intensive sampling is done so that the result should be accurate .

In this two methods are used on the basis of clustered in equally sized areas or when clustered are not equal in size . When the Clumped samples are clustered in equally sized areas random clustered sampling is performed. And if it is not equal in size than probability proportionate to size sampling is performed.