environmental science chapter 2

producers

(autotroph) an organism that uses energy from sunlight to produce its own food. includes green plants, algae, and cyanobacteria

-kinetic energy (energy of motion) and potential energy (energy of position) -Processes for kinetic energy are thermal energy, light energy, sound energy, and electrical energy. Processes for potential energy are chemical energy, mechanical energy, and nuclear energy.

1) what are the two main sources of energy on Earth? 2) Identify at least two processes powered by each energy source.

negative feedback loop

A feedback loop in which output of one type acts as input that moves the system in the opposite direction. The input and output essentially neutralize each other's effects, stabilizing the system.

positive feedback loop

A feedback loop in which output of one type acts as input that moves the system in the same direction. The input and output drive the system further toward one extreme or another.

The Chesapeake Bay is an example of a system. It is open because it exchanges energy, matter, and information with other systems. Some inputs include the Susquehanna river, pollutants, bi-products, pathogens, flooding, and improper disposal of waste. The matter that ends up in the system, like fertilizers, affects marine life, including phytoplankton. The energy put into the system affects the water, like nutrients. An emergent property is that it contains phytoplankton and oysters, which help to clean the waters. A positive feedback loop is people fishing for oysters. Without oysters, the nutrient balance in the bay is off, which will affect all of the marine life in there. This is a tipping point because the whole bay could lose all life without them, and the oyster population is depleting. This destablizes the system.

Identify a system, and describe it terms of systems thinking. Is it open or closed (explain)? What are the inputs and outputs (and what process(es) create the outputs)? What source(s) of energy poers the system, and what happens to the matter and energy putinto the system (how is the energy transformed, what happens to the matter?). Describe anemergent property of your system. Are there any positive (reinforcing) or negative (balancing) feedback loops that can destabilize or stabilize your system? Any tipping points?

feedback loop

a circular process in which a system's output serves as input to that same system

carbon cycle

a major nutrient cycle consisting of the carbon atoms take through the nested networks of environmental systems

nitrogen cycle

a major nutrient cycle consisting of the routes that nitrogen atoms take through the nested networks of environmental systems

phosphorus cycle

a major nutrient cycle consisting of the routes that phosphorus atoms take through the nested networks of environmental systems

system

a network of relationships among a group of parts, elements, or components that interact with and influence one another through the exchange of energy, matter, and/or information

ecosystem

all organisms and nonliving entities that occur and interact in a particular area at the same time

hydrosphere

all water - salt or fresh, liquid, ice, or vapor - in surface bodies, underground, and in the atmosphere

estuary

an area where a river flows into the ocean, mixing fresh water with salt water

-Five ecosystem services provided by functioning ecosystems are clouds store water and regulate water flow, bees pollinate plants, fish provide food, clouds regulate climate change, and forests provide timber and other resources. -

List five ecosystem services provided by functioning ecosystems (in this chapter and discussed in class for Chp 1. Which of your five examples do you think is most important? Explain.

ecosystem services

an essential service an ecosystem provides that supports life and makes economic activity possible. for example, ecosystems naturally purify air and water, cycle nutrients, provide for plants to be pollinated by animals, and receive and recycle the waste we generate

consumers

an organism that feeds on plants or other animals for energy

kinetic energy

energy of motion

potential energy

energy of position

open systems

exchanges energy, matter, and information with other systems

closed systems

isolated and self contained - only energy moves in/out

phytoplankton

microscopic photosynthetic algae, protists, and cyanobacteria that drift in near the surface of water bodies and generally form the first trophic level in an aquatic food chain

geosphere

nonrenewable resources (any of the almost spherical concentric regions of matter that make up the earth and its atmosphere, as the lithosphere and hydrosphere)

chemical energy

potential energy held in the bonds between atoms

energy

the capacity to change the position, physical composition, or temperature of matter; a force that can accomplish work

nutrient cycles

the comprehensive set of cyclical pathways by which a given nutrient moves through the environment

hypoxic/hypoxia

the condition of extremely low dissolved oxygen concentrations in a body of water

hydrologic cycle

the flow of water - in liquid, gaseous, and solid forms - through our biotic and abiotic environment. also called the water cycle

1st law of thermodynamics

the physical law stating that energy can change from one form to another, but cannot be created or lost. the total energy in the universe remains constant and is said to be conserved

2nd law of thermodynamics

the physical law stating that the nature of energy tends to change from a more-ordered state to a less-ordered state; that is, entropy increases

nitrogen fixation

the process by which inert nitrogen gas combines with hydrogen to form ammonium ions, which are chemically and biologically active and can be taken up by plants

eutrophication

the process of nutrient enrichment, increased production of organic matter, and subsequent ecosystem degradation in a water body

biosphere

the sum total of all the planet's living organisms and the abiotic portions of the environment with which they interact

atmosphere

the thin layer of gases surrounding planet Earth

-The carbon cycle is a major nutrient cycle consisting of the routes that carbon atoms take through nested networks of environmental systems. -Carbon is mainly stored in sedimentary rocks. - The fluxes include volcanic and hydrothermal emissions, runoff, burial, weathering, ocean-atmosphere exchange, fossil fuel combustion, fossil fuel extraction, reduced uptake by plants, respiration, decomposition, net deforestation, and GPP (gross primary production). -Humans change the natural carbon cycle by using fossil fuels as an energy source. The burning of coal, oil, and natural gas has greatly increased the flux of carbon from the lithosphere to the atmosphere and has shortened the residence time of carbon in fossil fuel deposits. Deforestation causes the carbon in wood and leaves to be released into the atmosphere. Then, photosynthesis removes less carbon dioxide from the atmosphere than before because less vegetation. It is a driving force behind anthropogenic global climate change.

Define "carbon cycle". Name the main places where carbon is stored (sources & sinks), name & describe the main processes (fluxes) that move carbon through the cycle. How do humans change the natural carbon cycle?

-The hydrologic cycle is the flow of water - in liquid, gaseous, and solid forms - through our biotic and abiotic environment. -Water is mainly stored in oceans, lakes, rivers, ponds, moist soil, ice caps, glaciers, snowfields and the atmosphere. -The fluxes include evaporation, precipitation, runoff, extraction, transpiration, human use, groundwater flow, uptake, and infiltration. -Humans change the natural hydrologic cycle by damming rivers and holding their water in reservoirs, which increases evaporation and slows the movement of water from land to sea. Humans remove natural vegetation by clear-cutting and developing land, which increases surface runoff, decreases infiltration and transpiration, and promotes soil erosion. Withdrawing surface water and groundwater depletes rivers, lakes, and streams and lowers water tables.

Define "hydrologic cycle". Name the main places where water is stored (sources & sinks), name & describe the main processes (fluxes) that move water through the cycle. How do humans change the natural hydrologic cycle?

-The nitrogen cycle is a major nutrient cycle consisting of the routes that nitrogen atoms take through the nested networks of environmental systems. -Nitrogen is mainly stored in the atmosphere. -The fluxes include fixation, volatilization, precipitation, denitrification, biotic cycling, emissions, runoff, burial, extraction and combustion, groundwater infiltration, deposition in precipitation, fixation by crops and fertilizer production, decomposition and waste, bacterial conversion, assimilation, fixation by lightning, and natural biological fixation. -Humans change the natural nitrogen cycle by fixing nitrogen. People fix nitrogen on massive scales, and they accelerated its flux into other resources. Today, humans are fixing at least as much nitrogen artificially as is being fixed naturally, and are overwhelming nature's denitrification abilities. Also, fertilizers strip soil of its nutrients. Burning fossil fuels, forests, or fields generates nitrogenous compounds in the atmosphere that act as greenhouse gases, cause acid deposition, promote eutrophication, and contribute to photochemical smog.

Define "nitrogen cycle". Name the main places where nitrogen is stored (sources & sinks), name & describe the main processes (fluxes) that move nitrogen through the cycle. How do humans change the natural nitrogen cycle?

-The phosphorous cycle is a major nutrient cycle consisting of the routes that phosphorus atoms take through the nested networks of environmental systems. -Phosphorous is mainly stored in sedimentary rocks. -The fluxes include biotic cycling, uptake, burial, runoff, pollution, erosion, weathering, mining, geologic uplift, and transport of dust and seaspray. -Humans change the natural phosphorous cycle by increasing concentrations of phosphorous in surface waters, most notably through runoff of the phosphorous-rich fertilizers we apply to lawns and farmlands. People also add phosphorous to waterways through releases of treated wastewater rich in phosphates from domestic use of phosphate detergents. These inputs promote eutrophication in waters such as the Chesapeake Bay.

Define "phosphorus cycle". Name the main places where phosphorous is stored (sources & sinks) and name & describe the main processes (fluxes) that move phosphorus through the cycle. How do humans change the natural phosphorous cycle?

-Pollution with high levels of nitrogen and phosphorous from agricultural fertilizers, animal manure, stormwater runoff, and atmospheric compounds produced by fossil fuel combustion impacts the water and surrounding areas. There are not that many oysters today, which filter nutrients from water, and this causes the phytoplankton populations in the bay to increase. When phytoplankton die, settle to the bay bottom, and are decomposed by bacteria, oxygen in the water is depleted. This condition, called hypoxia, creates dead zones in the bay. Other organisms either die or are forced to find new homes with more oxygen. If there are less fertilizers, then the bay would be healthier with less of it in the water since oysters are not really around to clean the water.

Describe how hypoxic conditions can develop in aquatic ecosystems such as the Chesapeake Bay, and predict how a reduction in use of fertilizers in the Susquehanna watershed would affect the development of dead zones in the Bay. Explain your answer.

-Energy moves through the ecosystem by light energy drives photosynthesis in producers, which begins the transfer of chem energy among trophic levels and detritus. Energy exits the system through respiration in the form of heat. -Matter moves through the ecosystem by nutrients flow among the trophic levels and detritus. In both diagrams, box sizes represent relative magnitudes of energy or matter content , arrow widths represent relative magnitudes of energy or matter transfer. Such magnitudes may vary tremendeously from one ecosystem to another -

Describe the typical movement of energy through an ecosystem - where does it come from, how is it used, and where does it go?. Describe the typical movement of matter through an ecosystem. Where does it come from, how is it used, and where does it go? How are these cycles different (where does waste energy end up vs. waste material)?

People alter the natural hydrologic cycle by damming rivers and removing natural vegetation. Damming rivers and holding water in reservoirs increases evaporation and slows the movement of water from land to sea. Removing natural vegetation increases runoff, decreases infiltration and transpiration, and promotes soil erosion. I benefit from both because dams help distribute water to people, and clearing vegetation makes way to plant food for people. I have felt the downside of these changes because both go against nature's natural course, which effects plants, animals, and eventually humans. The benefits do not outweigh the drawbacks. People should let nature be nature for a healthier environment. These both affect animal and plant life. Clearing vegetation takes away habitats for animals, and damming rivers negatively affects marine life.

Describe two things people do that alter the natural Hydrologic cycle. Explain why we do each of these things, as well as the consequences of each change. Do you benefit from either of these changes (explain why or why not)? Have you felt the downside of these changes (explain why or why not)? Do you feel the benefits of the changes outweigh the drawbacks? Explain your answer

-Positive feedback loops are a feedback loop in which output of one type acts as input that moves the system in the same direction. Negative feedback loops are a feedback loop in which output of one type acts as input that moves the system in the opposite direction. -Negative feedback loops are more common in nature because they exert a stabilizing influence on systems. Positive feedback loops are more commonly results from human action because they have a destabilizing effect. -Sweating is an example of negative feedback loop because the body is too hot so it cools it off by releasing sweat. Ripening of fruit is an example of a positive feedback loop.

Explain positive and negative feedback loops. Which type of feedback loop is more common in nature, and which more commonly results from human action (explain)? Give an example of each type (NOT from the book), and make sure you can explain WHY it is a good example.

-Geosphere is nonrenewable resources (any of the almost spherical concentric regions of matter that make up the earth and its atmosphere, as the lithosphere and hydrosphere). -Atmosphere is the thin layer of gases surrounding planet Earth. -Hydrosphere is all water - salt or fresh, liquid, ice, or vapor - in surface bodies, underground, and in the atmosphere. -Biosphere is the sum total of all the planet's living organisms and the abiotic portions of the environment with which they interact.

Name and define the four "spheres", and provide at least two examples of how material moves from one sphere to another (Not sure about the last part? Look at the cycles (hydrologic, rock, carbon, nitrogen, phosphorous) discussed at the end of the chapter to see how material moves from sphere to sphere)

The Chesapeake Bay is an environmental system. It is open because it exchanges energy, matter, and information with other systems. Some inputs include the Susquehanna river, pollutants, bi-products, pathogens, flooding, and improper disposal of waste.

Pick an environmental system, and explain it in terms of the properties of a system we discussed in class.

denitrifying bacteria

bacteria that convert the nitrates in soil or water gaseous nitrogen and release it back into the atmosphere