As human population and technology have increased, so too has the damage caused to the natural environment and world's ecosystems. Some impacts of human expansion include loss of natural vegetation, reduced air and water quality, water scarcity, pollution, and decline or loss of plant and animal species. Ecosystems are complex and interconnected systems in which organisms interact, and they have the ability to adjust to some change over time through ecological succession. The Earth contains a variety of different biomes, or large landscapes, which differ based on climate, rainfall, soils, topography, and other physical conditions, and each biome contains unique plant and animal communities adapted to its environment.