J and S Curves

1. J and S Curves

2. 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.

3. 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.

4. 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.

5. 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.

6. 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.

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