In contrast, small islands have high extinction rates and low colonization rates. Thus, small 'islands' will have fewer species than large 'islands. Three examples of the consequences associated with suppressing natural variation. For example, regulation of desert rivers in the Southwest allowed exotic species to out compete native species that were accustomed to the highly irregular water flow. For example, fire suppression causes fire loads to build up.
People insist on living in the flood plains of major rivers.
To accommodate this behavior, we controlling the flood dynamics of the rivers with dikes, levees, etc. Eventually, however, a flood comes that is big enough and causes unprecedented economic damage. Moreover, the people who receive the benefit of living in the floodplain do not pay for the full cost of living on the floodplain. Three methods for estimating the number of species on earth. The estimate was 30 million species.