What are three changes that might cause an environment to change-- that might alter the availability for resources in an environment.

If the water table is depleted, this could have far
reaching effects. In some areas, water is diverted to cities for use and the water table
becomes very low. The environment would dry up. Water is a necessary resource.Plants
adapted to a certain amount of water might not be able to withstand a lack of water and
could die off as a result.  The herbivores in turn, would die off and then carnivores
and omnivores would also become diminished. Another change in the environment that could
alter the amount of resources would be light availability. For instance, if there is a
volcanic eruption spewing much ash and debris into the atmosphere, this could cut down
on light penetrating to the Earth's surface. A lack of light would alter the amount of
producers that could live and grow. This shortage of plants in turn, would affect oxygen
levels which would decrease and also, it would affect food chains, as plants are the
basis of all food chains. Another environmental change is deforestation. When land
developers cut down trees to develop housing and other projects, this causes less oxygen
to be produced and more carbon dioxide to remain in the atmosphere. This can lead to
global warming. Less trees means less roots to absorb precipitation. This causes
flooding and runoff. When water runs downhill, it carries topsoil away, another resource
needed for plants to grow. It can take hundreds of years to produce more topsoil. These
are some examples of changes that could affect the environment and alter the
availability of resources within that environment.