CHAPTER 3 Earth’s Environmental Systems Lesson 3.2 Systems in Environmental Science Positive feedback loops can help erosion turn a fertile field to desert in just a few years. Dust storm, Stratford Texas, 1930s Lesson 3.2 Systems in Environmental Science Interacting Systems • Inputs into Earth’s interconnected systems include energy, information, and matter. • Feedback loops regulate systems. Negative feedback loop • Negative feedback loops: Result in stabilization of a system • Positive feedback loops: Result in a system moving to an extreme Did You Know? Predator-prey cycles are negative feedback loops. If prey populations rise, predator populations can rise in response, causing prey populations to fall. Then predator populations may decline, allowing prey populations to rise again, and so on. Predator-prey cycles are negative feedback loops. If prey populations rise, predator populations can rise in response, causing prey populations to fall. Then predator populations may decline, allowing prey populations to rise again, and so on. Did You Know? QuickTime™ and a decompressor are needed to see this picture. Lesson 3.2 Systems in Environmental Science Spheres of Function • Earth can be divided into spheres that are defined according to their location and function. Geosphere, Lithosphere • Geosphere-made of rock and anything BELOW Earth’s surface. • Lithosphere-the hard rock on or below Earth’s surface • Biosphere-Consists of all living or once living things thrived QuickTime™ and a decompressor are needed to see this picture. Atmosphere & Hydrosphere • Atmosphere-all layers of gas that surrounds out planet • Hydrosphere-encompasses all water • Ex. Great lakes are part of the Hydrosphere QuickTime™ and a decompressor are needed to see this picture. QuickTime™ and a decompressor are needed to see this picture. Crust, Mantle, & Core Quic kTime™ and a dec ompres s or are needed to s ee this pic tur e.