BESC 201 1ST Edition Lecture 3 Outline of Last Lecture I Part II of Introduction to Environmental Science Outline of Current Lecture II Central Case Study of Chapter 2 III Earth s Environmental Systems IV Chemistry and the Environment Chapter 2 Lecture 3 Environmental Systems Matter Energy and Ecosystems Central Case Study The Vanishing Oysters of the Chesapeake Bay Deal Island was ruined economically and ecologically because of people decimating the Chesapeake Bay oyster fishery Watershed the land area that funnels water to the bay through rivers Biggest impact increase of nitrogen and phosphorus led to phytoplankton increasing and not regulated via oyster filtration their decomposition of bacteria increased O2 hypoxia leading to dead zones in the bay Earth s Environmental Systems Issues are multifaceted and connected using a systems approach is best Systems involve feedback loops System a network of relationships among components that interact with and influence one another through exchange of energy matter or info Feedback loop a system s output can serve as input to that same system These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Negative input and output stabilize each other enhance stability homeostasis thermostat Positive input and output drive it further toward an extreme melting glaciers and global warming Environmental Systems Interact Lithosphere rock and sediment Atmosphere air surrounding planet Hydrosphere all water in surface bodies underground and in atmosphere Biosphere all living and nonliving portions Identifying the boundaries of systems depends on what you re looking for Dead zones in Chesapeake Bay because of pollutants from watershed and airshed Oxygen replenishes slowly because it stays in a layer near the surface and mixes slowly with denser saltier bay water where the oysters and life are Eutrophication process of nutrient overenrichment blooms of algae increased production of organic matter and subsequent ecosystem degradation Chemistry and the Environment Atoms and elements are chemical building blocks Nutrient elements needed in large quantities by organisms carbon Matter is composed of organic and inorganic compounds Organic compounds carbon atoms joined by bonds may include other elements Inorganic compounds lack carbon carbon bonds Hydrocarbons consist solely of atoms of carbon and hydrogen make up fossil fuels Macromolecules are building blocks of life Polymers long chains of repeated molecules proteins nucleic acids carbohydrates Lipids aren t polymers but are added to the list of macromolecules
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