Populations show characteristic growth patterns or forms. These patterns can be plotted and termed as J - shaped growth form and S - shaped growth form (Sigmoid form). Their growth is represented by S shaped growth cure. J shaped growth form : When a population increases rapidly in an exponential fashion and then stops abruptly due to environmental resistance or due to sudden appearance of a limiting factor, they are said exhibit J - shaped growth form. Many insects show explosive increase in number during the rainy season followed by their disappearance at the end of the season. S- Shaped growth form (sigmoid growth) Some populations, as in a population of small marmmals, increase slowly at first then more rapidly and gradually slow down as environmental resistance increases whereby equilibrium is reached and maintained. Their growth is represented by S shaped growth curve.
