7.2a Human activities that degrade ecosystems result in a loss of diversity of the living

and nonliving environment. For example, the influence of humans on other organisms

occurs through land use and pollution. Land use decreases the space and resources

available to other species, and pollution changes the chemical composition of air, soil,

and water.

7.2b When humans alter ecosystems either by adding or removing specific organisms,

serious consequences may result. For example, planting large expanses of one crop

reduces the biodiversity of the area.

7.2c Industrialization brings an increased demand for and use of energy and other

resources including fossil and nuclear fuels. This usage can have positive and negative

effects on humans and ecosystems.