But there are some exceptions. There appears to be some correlation between vegetation gain and loss. In other words, gain and loss appear to be high together, or low together, on average. Figure 3.39 shows the clearest pattern of high rates of change along the coast and decreasing westward. Within Watersheds We have seen that vegetation change is not uniformly distributed over the region.
Some watersheds show high rates of vegetation change, while others are low.
First-order streams are small streams at the top of the watershed. This area is usually the steepest portion of the watershed and therefore can be more impacted by the loss of vegetation. Figures 3.40 through 3.42 show the difference between observed and expected values for vegetation loss, gain, and total change in first-order stream regions. The opposite seems to be the case for vegetation gain. This pattern suggests that some portion of vegetation gain is associated with human activities.