Which type of feedback loop is more common in nature, and which more commonly results from human action? how might the emergence of a positive feedback loop affect a system in homeostasis? describe how hypoxic conditions can develop in ecosystems such as the chesapeake bay. what is the difference between an ecosystem and a community? describe the typical movement of energy through an ecosystem. now describe the typical movement of matter through an ecosystem. explain net primary productivity. name one ecosystem with high net primary productivity and one with low net primary productivity. why are patches in a landscape mosaic often important to people who are interested in conserving populations of rare animals? what is the difference between evaporation and transpiration? give examples of how the water cycle interacts with the carbon, phosphorus, and nitrogen cycles. what role does each of the following play in the carbon cycle? cars photosynthesis the oceans earth’s crust distinguish the function performed by nitrogen-fixing bacteria from that performed by denitrifying bacteria. how has human activity altered the carbon cycle? the phosphorus cycle? the nitrogen cycle? what environmental problems have arisen from these changes?