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.
The first is the elment called weather. When the weather changes drastically due to environmentally-caused events crops get affected as well as the people who grow them. Weather can turn crops that are often used to a specific temperature to die, or not reproduce.
People can cause the environment to change because if people continue to push toxins into the atmosphere, biosphere, and hydrosphere layers, the natural biodegradable process will be affected.
Finally, the economy can cause an environment to change because if there isn't enough money to fund a good recycling and environmental program there cannot be enough help to dispose of harmful materials that could lead to a healthy lifestyle.