Long description

A hypothetical line graph that shows how species diversity changes with frequency of disturbance. The horizontal axis is labeled ‘frequency of disturbance’ and the vertical axis is labeled ‘species diversity’. There are no quantitative markings on the vertical axis. On the horizontal axis, the extreme left-hand side is labeled ‘low’ and the extreme right hand side ‘high’. The line of the graph starts on the bottom left, increases almost linearly, reaches a peak and then decreases linearly to reach a low value again. So, it is an inverted U-shape. Underneath the graph is a series of three pictures of vegetation. The one on the left which is aligned with the left-hand side of the graph, shows a landscape with mostly grass interspersed with a few small trees. The central picture, which is aligned with the peak on the graph shows a mixture of low vegetation such as grass and shrubs, small trees and larger trees. The third picture which is aligned with the right-hand side of the graph shows mostly large trees. The graph and the pictures together illustrate that at a low frequency of disturbance (LHS of the graph, LH picture), species diversity is low; at an intermediate frequency of disturbance (peak on graph, central picture) diversity is high and reaches a peak; and at a high frequency of disturbance (RHS of graph, RH picture) diversity is once again low.