J and S Curves

If things were perfect for a population and all the individuals survived and reproduced at the maximum rate, that growth rate is called the biotic potential. It is certainly not common for a population to grow at its biotic potential. When fish are introduced into a lake where there is plenty of food and space and there are no predators, the fish can reproduce at their biotic potential, but not for a long time.

J and S Curves The graph of a population growing at its biotic potential, which is called exponential, can be very steep. The graph of a population that grows exponentially is called a J-shaped curve.

J and S Curves Carrying Capacity of an Ecosystem The area occupied by a population can’t provide unlimited resources such as food and water. These factors limit the population growth and many times bring about death rates that equal the birth rates. When this happens, the population size reaches a stable balance.

J and S Curves The graph of a population that grows until it reaches a stable size based on the carrying capacity is called an S-shaped curve.

J and S Curves A.Begins with a slow rate of growth. E. As the number of mates increase, the growth rate speeds up. C. When the population reaches a certain level, growth rate slows down and population reaches a steady state.

J and S Curves At this point, if environmental conditions remain stable, population will continue to exhibit minor fluctuations.