Enviro unit 3

Trophic pyramid

A representation of the distribution of biomass, numbers, or energy among trophic levels

Describe how the first and second law of thermodynamics applies to ecosystems

The First law applies to ecosystems because when an organism needs usable energy it must convert it from an energy source like the sun or food. Organisms gaining energy from sources such as sunlight proves that energy is neither created nor destroyed but can change from one form (sun) to another (usable energy). The second law of thermodynamics states that when energy is transformed, the quantity of energy remains the same, but its ability to do work diminishes. The second law of thermodynamics applies to an ecosystem because in an ecosystem, energy conversions are not completely efficient, and some energy is always lost as heat. The second law illustrates that all systems move toward randomness rather than toward order. This randomness in a system called entropy is always increasing unless new energy is added to create order.

Scavenger

An organism that consumes dead animals

Describe the two factors that cause unequal heating of the Earth and affect seasonal differences in climate

- Differences in the angle of the Sun's rays that strike Earth- the regions nearest to the equator the sun strikes more direct while near the polar regions the sun's rays are less direct. The sun rays travel a short distance through the atmosphere to reach the tropics but longer to reach the poles; and because solar energy is lost as it travels through the atmosphere more solar energy reaches the equator than the poles. - The amount of surface area over which the Sun rays are distributed- The angle at which the suns rays strike the Earth changes with the time of the year. When the sun's rays strike near the equator the solar energy is distributed over a smaller surface area than near the poles. Therefore regions near the equator receive more solar energy per square meter than polar regions. Earth's tilt causes seasonal changes in climate because the amount of solar energy a region receives is based on the angle of the Sun's rays. Therefore because of the Earth's tilt temperature and precipitation all over the world can be changed as the Earth rotates and this is because the earth is tilted.

Explain fully the process of eutrophication and the formation of dead zones.

A dead zone is an area of an ocean, estuary, river, lake or other water body with low DO (hypoxic conditions) or no DO (anoxic conditions) that cannot support most marine life.. A dead zone is one example of eutrophication, which means an ecological imbalance that occurs as a result of excess nutrients. A significant cause of Dead Zones is excess nutrients (nitrogen, phosphorus). - Marine life needs some nitrogen to survive. Phytoplankton require it for survival. When excess nitrogen is put into the water, phytoplankton can reproduce very quickly. Excess material causes eutrophication, a disruption in the balance of the normal nitrogen cycle. When phytoplankton die, decomposition occurs and can reduce the dissolved oxygen (DO) in the water. Low levels of DO can lead to dead zone formation. Fortunately, dead zones are reversible if their causes are reduced or eliminated.

Define the concept of limiting nutrients and explain why phosphorus is limiting in most aquatic ecosystems while nitrogen is a limiting nutrient in most terrestrial ecosystems.

A limiting nutrient is a nutrient required for the growth of an organism but available in a lower quantity than other nutrients. Because so much nitrogen is required, nitrogen is often a limiting nutrient for producers in terrestrial ecosystems. - Because the quantities of phosphorus in soil are generally small, it is often the limiting factor for plant growth. Phosphates are also limiting factors for plant-growth in marine ecosystems, because they are not very water-soluble. - Nitrogen gas (N2) makes up nearly 80% of the Earth's atmosphere, yet nitrogen is often the nutrient that limits primary production in many ecosystems and this is because plants and animals are not able to use nitrogen gas in that form.

Explain how positive and negative feedback loops can each play a role in food webs.

A positive feedback loop can impact food webs because an increase in the population leads to more births, which increases the population even more. As for negative feedback loops, an increase in the population reduces the food supply so less food means more deaths and fewer births. Plants and animals live, eat, reproduce, and die within these food webs, which can either create balance or instability in the habitats that they live in. The push and pull for balance in an ecosystem or any biome is made of positive and negative feedback loops.

Describe the characteristics of a watershed including area, slope, and divides with adjoining watersheds.

A watershed is the area of land that drains into a particular body of water. Watershed studies help us understand how disturbances affect ecosystem processes. Watersheds are defined by divides which are the highest points all around a river. Tributaries are small rivers that lead to a larger river going through a watershed. Area is how big the watershed is, some watersheds are very big while others are much smaller. Slope can impact the richness of the soil for example soil on slopes of high watersheds may be less nutrient rich and support plants.

Explain how the movement of air currents over mountain ranges affects climates

Air moving inland from the oceans contains a large amount of water vapor and when this air meets the windward side of a mountain range- the side facing the wind- it rises and begins to experience adiabatic cooling. Because of this cooling rain begins to fall and this condensation causes heat release which accelerates the upward movement of air. Therefore on a mountain range there is large amounts of precipitation on the windward side and dry conditions on the leeward side because of warm dry air. The dry region formed on the leeward side of a mountain range as a result of humid winds from the ocean causing precipitation on the windward side is known as rain shadow.

Define an ecosystem and distinguish between the biotic and abiotic components.

An ecosystem is a biological community of interacting organisms and their physical environment. An ecosystem is made up of interacting abiotic and biotic factors. Biotic organisms are all living things in an ecosystem while abiotic organisms are the nonliving physical or chemical components of an ecosystem.

Explain why estuaries are ecologically and economically significant

An estuary is an area of coast where saltwater and freshwater mix, a very productive area. Estuaries are important natural places. In addition to essential habitats for birds, fish, insects, and other wildlife, estuaries provide goods and services that are economically and ecologically indispensable, such as commercial fishing and recreational opportunities. Estuaries filter out sediments and pollutants from rivers and streams before they flow into the ocean, providing cleaner waters for humans and marine life.

Explain the pattern of atmospheric circulation via convection currents and global winds.

Atmospheric convection currents are global patterns of air movement that are initiated by the unequal heating of Earth. These air currents are called convection currents because they involve the movement of air that absorbs and releases heat as the air moves up into the atmosphere and then back to Earth. Atmospheric convection currents on Earth are found at specific locations. - Hadley cells- are convection currents that cycle between the equator and approximately 30N and 30S, air near the equator expands and rises, eventually as it rises higher it cools and condensed water falls over the tropics, cold dry air then goes back towards the equator to once again warm up - Polar cells- convection currents formed by air that rises at 60N and 60S and sinks at the poles. At the 60's rising air cools and water vapor becomes rain. The air dries as it moves towards the poles and sinks back to Earth's surface. At the poles air moved back towards the 60's completing the cycle - Ferrel cells- lies between Hadley cells and polar cells. Air currents here do not form distinct convection cells but are driven by the circulation of the neighboring cells.

Explain how energy flows and matter cycles through trophic levels within ecosystems.

Consumers cannot do photosynthesis so they must obtain their energy by consuming organisms which is why energy flows throughout an ecosystem. The successive levels of organisms consuming one another are trophic levels. The 10% rule applies to trophic levels and states that only 10% of energy is passed on to each trophic level which; so by the tertiary consumer is consuming little energy but they just eat more; this creates the trophic pyramid. The laws of thermodynamics illustrate how and why this energy flow is happening, not energy is ever destroyed so when another organism eats a producer it gains energy. The second law of thermodynamics helps illustrate energy efficiency and how energy is not always 100% used.

Adiabatic temperature changes (heating/cooling)

Cooling: The cooling effect of reduced pressure on air as it rises higher in the atmosphere and expands Heating: The heating effect of increased pressure on air as it sinks towards the surface of Earth and decreased in volume.

Describe the following special properties of water and why they are essential to environmental science: density as a solid, capillary action, surface tension, universal solvent, nutrient cycling

Density as a solid: As liquid water cools it reaches a max density at 39 (4C) therefore water is always going to be more dense than ice. This is essential to enviro because if water was like other liquids, ice would end up being more dense than water and all the cold ice in oceans, lakes, and rivers would sink to the bottom so only a few aquatic organisms would be able to survive. Capillary action: This happens when adhesion of water molecules to a surface is stronger than cohesion between the molecules. This is important in thin tubes, such as the water-conducting vessels in tree trunks and in small pores in the soil. It is also important in the transport of underground water, as well as dissolved pollutants from one location to another. EX: the absorption of water by a paper towel or sponge is the result of capillary action Surface tension: Results from the cohesion of water molecules at the surface of a body of water, creating a sort of skin on the surface. Surface tension allows aquatic insects to walk across the surface of water. Surface tension also makes water droplets smooth and more or less spherical as they sling to a water faucet before dripping. Universal solvent: Water makes a very good solvent which makes it super easy for ions to be dissolved in water. Water being a good solvent allows a high concentration of dissolved ions in seawater, but also allows organisms to store many types of molecules in solution in their cells. Many toxic substances also dissolve well in water which makes them easy to transport through the environment. EX: Fertilizers, human waste, and road deicers such as road salt are all pollutants that dissolve easily in water and so are transported far from their sources. Nutrient cycling: As water moves through and across soils, it carries valuable nutrients. As a landscape captures water it will also capture many of the nutrients dissolved in the water. As water transpires or evaporates through the plant's stomata, water is pumped up from the soil through the roots and into the plant. That water carries with it minerals and nutrients from the soil that are essential for plant growth.

Determine how the energy decreases as it flows through ecosystems by quantifying ecosystem productivity (be able to calculate GPP and NPP and define their units of measurement)

Ecosystem productivity helps scientists to understand where energy in an ecosystem comes from and how it flows throughout the ecosystem. The gross primary productivity (GPP) of the ecosystem is a measure of the total amount of solar energy that the producers in the system capture via photosynthesis over a given amount of time. (GPP does not subtract the energy that is lost when the producers respire). An ecosystems net primary productivity (NPP) is the energy captured MINUS the energy respired by producers (NPP = GPP-respiration by producers). GPP is essentially the total amount of photosynthesis occurring over some amount of time. Only 1% of solar energy striking producers is captured by photosynthesis.

Distinguish between food chains and food webs and their constituent members by trophic levels.

Food chains link producers and consumers in a linear fashion which illustrates how energy and matter move through the trophic levels of an ecosystem. Food chains start with producers, then primary consumers, then secondary consumers, then finally tertiary consumers. Food webs are more realistic representations of trophic relationships than simple food chains. Webs include scavengers (eat dead organisms), detritivores, and decomposers, and they recognize that some species feed at multiple trophic levels. Arrows indicate the direction of energy movement in a food web, it is a real but somewhat simplified food web; in an actual ecosystem, many more organisms are present.

Herbivore (primary consumer) and detrivore

Herbivore: A consumer that eats producers Detritivore: an organism that specializes in breaking down dead tissues and waste products into smaller particles.

Describe the impacts of human activity on wetlands and mangroves.

Human impact such as dredging, filling, water pollution from herbicides and development can lead to mangrove erosion and habitat destruction. When mangrove forests are cleared and destroyed, they release massive amounts of carbon dioxide into the atmosphere, contributing to climate change. Human activities cause wetland degradation and loss by changing water quality, quantity, and flow rates; increasing pollutant inputs; and changing species composition as a result of disturbance and the introduction of nonnative species.

Provide three examples of natural disturbances and describe how they can impact ecosystems.

Hurricanes: Hurricanes can cause a tremendous amount of damage to homes and ecosystems. Hurricanes generate strong winds that can cause dramatic structural changes in wooded ecosystems. Animals can either be killed by hurricanes or impacted indirectly through changes in habitat and food availability caused by high winds, storm surge, and intense rainfall. Forest Fires: Fire as a destructive force can rapidly consume large amounts of biomass and cause negative impacts such as post-fire soil erosion and water runoff, and air pollution. Flames cause chemical changes to soils, drive out animals, and expose areas to far more sun and rain than they once experienced. Tsunamis: A tsunami changes the landscape. It uproots trees and plants and destroys animal habitats. Land animals are killed by drowning and sea animals are killed by pollution if dangerous chemicals are washed away into the sea, thus poisoning the marine life.

Describe how human activities impact each of the biogeochemical cycles listed above.

Hydrologic: A number of human activities can impact on the water cycle: damming rivers for hydroelectricity, using water for farming, deforestation, water pollution and the burning of fossil fuels. Using water for farming disrupts the water cycle by taking water out of the cycle and not returning it. Deforestation can disrupt the water cycle because it adds carbon dioxide into the atmosphere which can disrupt the cycling of water Burning of fossil fuels raises the Earth's temperature which means that there will be more evaporation leading to a disruption of the water cycle. Carbon: Humans affect the carbon cycle by burning fossil fuels and cutting down trees. Car exhausts and factory emissions produce a lot of extra CO2 in the atmosphere. The combustion of fossil fuels, deforestation, and transportation all are increasing atmospheric concentrations of carbon dioxide which upsets the balance between Earth's carbon pools and the atmosphere Nitrogen: Farming, fires, burning fossil fuels, and paving roads. Burning fossil fuels, application of nitrogen-based fertilizers, and other activities can dramatically increase the amount of biologically available nitrogen in an ecosystem. Intensive cultivation of legume crops affects the nitrogen cycle because it creates nitrogen in the atmosphere. Phosphorus: Humans greatly influence the phosphorus cycle through the release of mined phosphates into ecosystems, especially in the form of fertilizers, but also from detergents and sewage waste. Mining phosphorus and transporting it in fertilizers increases the amount of phosphorus in the atmosphere and offsets the phosphorus cycle Agricultural crops are altering the global phosphorus cycle, causing phosphorus to accumulate in some of the world's soil Detergents and sewage waste release mined phosphates into ecosystems and throw off the phosphorus cycle

Describe the main reservoirs and reservoir interactions in each of these biogeochemical cycles:, hydrologic (water), carbon, nitrogen, phosphorus cycles

Hydrologic: The oceans are the primary reservoir of water at the Earth's surface, with ice caps and groundwater acting as much smaller reservoirs. As well as glacier ice, lakes, soil moisture, living organisms, the atmosphere and rivers. Carbon: Most of Earth's carbon is stored in rocks and sediments. The rest is located in the ocean (largest reservoir), atmosphere, and in living organisms. Nitrogen: The largest reservoir of nitrogen is found in the atmosphere, mostly as nitrogen gas (N2). Nitrogen gas makes up most of the air we breathe. Most nitrogen enters ecosystems via certain kinds of bacteria in soil and plant roots that convert nitrogen gas into ammonia (NH3). Other main reservoirs include living organisms, soils, and oceans. Phosphorus: The ocean sediments are the greatest reservoirs of phosphorus. The reservoir of phosphorus in ecosystems is rock, where it is bound to oxygen in the form of phosphate. As phosphate-rich rocks are exposed and eroded, rainwater dissolves the phosphate. Dissolved phosphate is absorbed through the roots of plants. Other main reservoirs include water, soil and sediments.

Identify the major ocean zones and how they are defined: intertidal, benthic, open ocean, photic, aphotic

Intertidal- The narrow band of coastline between the levels of high tide and low tide Benthic- The muddy bottom of lake, pond, or ocean Open Ocean- Deep ocean water, located away from the shoreline where sunlight can no longer reach the ocean bottom Photic- The upper layer of ocean water in the ocean that receives enough sunlight for photosynthesis Aphotic- The deeper layer of ocean water that lacks sufficient sunlight for photosynthesis, use chemosynthesis to generate energy. Chemosynthesis is a process used by some bacteria in the ocean to generate energy with methane and hydrogen sulfide.

Explain how wavelengths of light are absorbed differently in aquatic ecosystems and how this pattern influences primary productivity.

Longer wavelengths such as red are absorbed at a shallower depth than shorter wavelengths such as blue, which penetrates to a deeper depth. Because light is required for photosynthesis, phytoplankton and other primary producers are restricted to the ocean's uppermost layers, where light is abundant sufficiently to sustain the reaction.Increased light, while generally beneficial to primary production, is not always beneficial to aquatic organisms.UV-A and UV-B radiation can damage genetic material, acting as a stressor by putting intracellular repair mechanisms under strain.

Law of Conservation of Matter

Matter is not created nor destroyed in any chemical or physical change

Compare ecosystem productivity among ecosystems. Explain what accounts for the large difference in NPP among different ecosystems.

Measurement of NPP allows us to compare the productivity of different ecosystems. Producers grow best in ecosystems where they have plenty of sunlight, lots of water and nutrients available, and warm temperatures. The greater productivity in an ecosystem the more primary consumers can be supported. Since productivity varies depending on temperature and solar energy, this difference can cause a difference in NPP among different ecosystems.

Processes and products of the nitrogen cycle

N2 in the atmosphere is converted into other types of nitrogen starting the cycle FixNAD and ANPAN Fixation -----> Amonia (NH3) Nitrification -----> Nitrates (NO3) Assimilation ------> Plants (ATE) Dentrification ----> N2 Bacteria is carrying out all of these processes of fixation, nitrification, denitrification

Identify the major gases of the atmosphere and their relative abundance.

Nitrogen — 78 percent. Oxygen — 21 percent. Argon — 0.93 percent. Carbon dioxide — 0.04 percent. Small amounts of neon, helium, methane, krypton and hydrogen, as well as water vapor are present in air.

Describe the factors that cause and influence surface ocean circulation.

Ocean circulation patterns are the result of differential heating, gravity, prevailing winds, the coriolis effect, and the location of the continents. The coriolis effect is the deflection of an object's path due to the rotation of Earth which ends up affecting the ocean current. These ocean currents end up causing a gyre which is a large-scale pattern of water circulation that moves clockwise in the Northern hemisphere and counterclockwise in the Southern hemisphere. Ocean currents also cause upwelling which is the upward movement of ocean water toward the surface as a result of diverging currents.

Describe fully the processes of photosynthesis and cellular respiration

Photosynthesis: The process by which producers use solar energy to convert carbon dioxide and water into glucose. Plants, algae, and some bacteria (producers) use photosynthesis to convert solar energy into glucose; it also produces oxygen which is why plants are so beneficial to the atmosphere Chemical equation: Solar energy + 6 H2O + 6 CO2 ------> C6H12O6 + 6 O2 Cellular respiration: The process by which cells unlock the energy of chemical compounds. Organisms that are not producers, eat the producers and gain energy through cellular respiration. Aerobic respiration is the opposite of photosynthesis and uses glucose and oxygen to produce energy. There is also anaerobic respiration which is when organisms do cellular respiration without oxygen. Chemical equation: Energy + 6 H2O + 6 CO2 ←------ C6H12O6 + 6 O2

Autotroph (producer) and heterotroph (consumer)

Producer: An organism that uses the energy of the sun to produce usable forms of energy Consumer: An organism that is incapable of photosynthesis and must obtain its energy by consuming other organisms/

Explain the Intermediate Disturbance Hypothesis and its application to ecosystem studies.

The Intermediate Disturbance Hypothesis is the hypothesis that ecosystems experiencing intermediate levels of disturbance are more diverse than those with high or low disturbance levels. Ecosystems in which disturbances are rare experience intense competition among species resulting in the most competitive species dominating the ecosystem. In places where disturbances are frequent only a few species are able to adapt. At intermediate levels of disturbance many more species are capable of persisting.

Biosphere

The region of our planet where life resides, the combination of all ecosystems on Earth.

Identify the six elements needed by living things and in which biological molecules (macronutrients) they are found.

The six most common elements in living things are carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur. Carbon- proteins, lipids, nucleic acids, and carbohydrates. Hydrogen- carbohydrates and proteins Oxygen- Carbohydrates, Nitrogen- proteins Phosphorus- nucleic acids Sulfur- proteins, carbohydrates, nucleic acids,

Describe the factors that influence deep ocean currents.

Thermohaline circulation is an oceanic circulation pattern that drives the mixing of surface water and deep water. This process is crucial for moving heat and nutrients around the globe; it is driven by surface waters that contain lots of salt. When water becomes cold and salty it is more dense so it sinks to the bottom of the ocean mixing with deeper ocean waters. The sinking of cold salty water at high latitudes and the rising of warm water near the equator creates the deep ocean currents. Ocean currents associated with thermohaline circulation affect the temperature of nearby land masses.

Describe the structure and composition of Earth's atmosphere.

Troposphere- Densest layer of the atmosphere layer where most of the atmospheres nitrogen, oxygen, and water vapor occur. It is the layer where the Earth's weather occurs. Air temperature decreases with distance from Earth's surface and varies with latitude. Greenhouse effect occurs here. Stratosphere: above the troposphere, less dense than the troposphere. Ozone forms a layer within the stratosphere, this ozone layer absorbs most of the sun's ultraviolet-B radiation and all of its ultraviolet-C radiation. Ozone layer provides critical protection from UV radiation; upper layers of the stratosphere absorb UV radiation and convert it into infrared radiation. Mesosphere: The atmospheric pressure and density in each of these layers continues to decrease as we move toward the outer layers of the atmosphere. Thermosphere: Particularly important to organisms on the Earth's surface because of its ability to block harmful X ray and UV radiation from reaching our planet. Contained charges gas molecules that when hit by solar energy begin to glow and produce light. Exosphere

Organic compound

a compound that contains carbon-carbon and carbon-hydrogen bonds

Polar molecule

a molecule in which one side is more positive and the other side is more negative

Decomposers

fungi and bacteria that convert organic matter into small elements and molecules that can be recycled back into the ecosystem

Ecological Efficiency

the proportion of consumed energy that can be passed from one trophic level to another

Biomass

the total mass of all living matter in a specific area

Leaching

the transportation of dissolved molecules through the soil via groundwater. Happens during the nitrogen cycle when nitrate is readily transported through the soil with water.

Upwelling

the upward movement of ocean water toward the surface as a result of diverging currents - When surface currents diverge it causes deep waters to rise and replace the water that has moved away. - The deep waters bring with them nutrients from the ocean bottom that support large populations of producers.

Hydrogen bond

weak attraction between a hydrogen atom and another atom