Dr. Hudson Material Flashcards
(165 cards)
1
Q
What effect do dissolved organic carbon (DOC) have on water?
A
Acts like a suntan lotion and protects organisms from UV light
2
Q
Define ecosystem
A
A biological community and its abiotic environment, functioning as a system. They exist at many spatial scales, anywhere from a pond to a biosphere
3
Q
Define ecosystem ecology and give a couple examples
A
Examines the flow of energy and chemical cycling in habitats, as well as, the effects of natural and human induced disturbances on ecosystems (ex: air/water pollution, tree harvesting, land-use changes)
4
Q
What are Energy Flow and Chemical Cycling and how are they different?
A
Energy Flow: The passage of energy THROUGH the components of an ecosystem.
Chemical Cycling: unlike energy flow, chemical cycling involves the circular (recycling) movement of materials within the ecosystem.
Energy flow then shows the energy from one level to the next in a system, while chemical cycling is for specific nutrients
5
Q
List Abiotic factors in the environment
A
Energy, inorganic substances (CO2, N, O2, minerals), Organic substances (proteins, carbs, humic acids), water.
6
Q
List examples of biotic inputs into an ecosystem
A
Animals migrating from one ecosystem to another, leaves falling from a tree on the ground or into a river.
7
Q
What are two things true about Energy? What are the two laws of thermodynamics that we studied in this course
A
P1: 1- Energy can be converted from one form to another.
2- All forms of life depend on these conversions. Think of photosynthesis.
1st Law: energy is neither created nor destroyed. Important when understanding our energy diagrams.
2nd Law: conversion of energy from one form or another is always accompanied by a reduction in the order of the universe. aka: energy is always lost when changing form.
8
Q
What is PAR? On what percentage of PAR reaches autotrophs?
A
PAR stands for Photosynthetically Active Radiation and falls between 380 and 710 nanometers. This is just under and just over the visible light spectrum. This is the radiant energy that is available for photosynthetic organisms. Only about 1% of PAR that reaches the autotrophs is converted to chemical energy like sugar.
9
Q
What are the primary producers of an ecosystem?
A
The autotrophs that produce organic material from inorganic chemicals and an energy source. They are the base of the food chain.
10
Q
Define Primary Production, and then the difference between GPP and NPP
A
The rate at which photosynthetic organisms convert solar energy to chemical energy (organic compounds). GPP stands for Gross Primary Production and describes the total amount of Carbon fixed per area per unit of time. Net Primary Production accounts for the energy lost during Gross Primary Production, and is the value that the organism actually outputs.
11
Q
What is biomass, how is it processed and in what unit?
A
Biomass is the amount of living organic material in an ecosystem (or a sub-component of the ecosystem. In terrestrial environments it is: grams dry matter per m^2 (g/m^2). In three dimensional environments such as aquatic: grams dry matter per m^3 ( g/m^3). Can also be replaced by carbon content instead of dry matter— grams of Carbon per meters squared or cubed.
12
Q
How does the Light-Dark Oxygen Method work to measure primary production?
A
The light bottle measures photosynthesis and respiration, while dark bottle only measures respiration. Light cannot enter the dark bottle and therefore we will have the values of respiration from the dark bottle and NPP from the light bottle to determine GPP. GPP will be NPP + Respiration. The bottle method usually uses two of each bottles. Take the mean of the two similar bottles.
Ex: Initial O2 content at dawn — 8 mg / L. 12 hours later, the clear bottle has 9.5 and 10.5 mg O2 / L and the darker bottles have 6 and 7 mg O2 / L. Notice how the dark bottles went down from their original O2 concentration.
To find the Net, we take 10 (the mean) minus 8 (start) to get 2 mg O2 / L. For respiration we take our starting value 8 - 6.5 (mean value of dark bottles) to get 1.5. GPP is now 2 + 1.5 = 3.5 mg O2 / L per 12 hours (DON’T FORGET TIME)
13
Q
List two of the other methods to measure primary production that we did not go into depth on
A
CO2 technique (radioactive carbon dioxide uptake) and changes in water column pH.
14
Q
What factors may control or limit primary production in Terrestrial systems? What about Aquatic?
A
Terrestrial: Intensity and Duration of Sunlight, Temperature, Moisture or Precipitation, Nutrient levels, especially Nitrogen.
Aquatic systems: Intensity and Duration of Sunlight, Temperature, Nutrient levels, particularly Nitrogen, Phosphorous, and Iron in the open water.
15
Q
What are more productive, Southerly Forests or Northerly Forests?
A
Overall, Southerly Forests are more productive since they are productive year long, opposed to Northerly Forests that are minimally productive in the winter months of little sunshine.
16
Q
What is the correlation between precipitation and temperature on productivity?
A
They are two of the major factors in productivity, as temperature and precipitation rise, productivity increases as well, starts to plateau when you get too much precipitation and temperatures get too high.
17
Q
What is it called when water is loss through the stomata in plants?
A
transpiration
18
Q
Compare the Calvin cycle under optimal temperature and moisture compared to when it is undergoing photorespiration
A
Under ideal conditions, there are high concentrations of CO2 and low O2 concentrations in the leaf of the plant. The Calvin cycle reduces CO2 and sugars are produced.
In dry, hot weather, the plant undergoes photorespiration because off the low amounts of CO2 and high O2 concentrations in leaf since the stomata closes to save water, therefore unable to exchange gasses. Calvin cycle uses O2 instead of CO2 and sugars are not produced, results in CO2 and H20
19
Q
What are CAM and C4 Plants?
A
CAM stand for Crassulacean acid metabolism. They only open their stomata at night to obtain CO2 when temperatures are low and water loss will be minimized, cacti are an example of this.
C4 plants keep stomata closed during dry and hot conditions, and use a special enzyme system to access very low internal concentrations of CO2. Examples are corn, sugar cane, sorghum.
20
Q
What affect does photorespiration have on C3 pants during hot and dry conditions? Is photorespiration a problem in C3 plants in hot and wet environments?
A
Photorespiration causes a reduction in C3 in hot and dry condition s up to 25%.
No, if the environment is wet, the stomata is open and photorespiration does not occur.
21
Q
What is the difference between Transpiration and Evaporation?
A
Transpiration is the loss of water vapour to the atmosphere by land plants. While Evapotranspiration is the loss of water vapour to the atmosphere from plants and the soil. When evaporation rates are high, primary transcription increases because of the use of water by the plant to produce sugars.
22
Q
If an ecosystem has adequate light, high temperatures, and sufficient moisture, but very low primary production, what is the problem?
A
Nutrients, there will be specific nutrients limiting primary production since the plants can’t operate to the best of their ability. These can be Carbon, Oxygen, Hydrogen, Phosphorous etc, also can be organic nutrients like vitamins. Any shortage of a nutrient can reduce primary production.
23
Q
Can a nutrient still limit rates of primary production when it is present in large concentrations?
A
Yes, many nutrients can occur at high concentrations in ecosystems but are not bioavailable. Nutrient concentrations alone are often poor predictors of primary production.
24
Q
What is the relationship between primary production and a limiting nutrient?
A
As the concentration of the limiting nutrient increases and is readily available in the environment, primary production increases. This is how fertilizers add to the environment.
25
What are the three factors that control primary production in aquatic ecosystems?
Quantity of light (PAR): northerly latitudes have shorter seasons for production.
Temperature: algal productivity increases with water temperature.
Nutrient supply: nutrients limit algal production in most environments.
26
What are the potential limiting nutrients in marine and freshwater systems? What is the one nutrient that differs between the two?
Nitrogen, Phosphorus, and Silicone. Iron is a limiting nutrient in marine systems but not in freshwater systems.
27
What does Nitrogen do for aquatic systems?
Ammonium (NH4), nitrate, and nitrite are the most important bioavailable forms of nitrogen and are used for protein synthesis in phytoplankton and bacterioplankton.
28
What does phosphorus do for an aquatic system?
Phosphate is the most important bioavailable form of phosphorus and is used for energy transfer (ATP), nuclei acid synthesis and cell membranes in algae and bacteria.
29
What does Iron do for a marine ecosystem?
Is bioavailable as ferrous iron Fe2+ and iron bound to organic ligands, is used to fix nitrogen (N2) and other functions in bacteria and algae.
30
What does silica do for aquatic environments?
Silicon acid H4SiO4 is the most important bioavailable form that is used in the skeleton of diatoms (a major algal group)
31
What did the study in 1969 at lake Kenora in Ontario determine and how was it done?
David Schindler the director, put up a plastic curtain separating the lake into two halves, they wanted to learn whether carbon, nitrogen, or phosphorus was the limiting factor in primary production. On one side they added Phosphorus which resulted in an algal bloom and lead to the banning of Phosphorus in detergents and reduction of Phosphorus inputs into sewage treatment plants to improve water quality.
32
Which nutrient is more often the limiting factor in aquatic ecosystems, Nitrogen or Phosphorus?
Phosphorus more often but either one or both can be limiting factors.
33
In the open ocean, which nutrient is most often the limiting factor and why does it have such an effect on temperature?
In the open ocean, iron is an important nutrient for phytoplankton to photosynthesize, also the belief was that having more iron in the water can capture more carbon from the atmosphere and hopefully cool down temperatures.
34
What are the effects of moderate grazing as a biotic factor in a prairie ecosystem? Compare this to low grazing and high grazing.
Moderate grazing rapidly release nutrients back into the environment through egestion, excretion, and decomposition for the re-uptake of vegetation, stimulating plant productivity. Low grazing permit nutrients to be locked up in biomass in vegetation, while high grazing rates reduces vegetation biomass to such low levels that autotrophs cannot increase biomass in the ecosystem.
35
How does grazing help a prairie?
Moderate grazing gets rid of old grass and allows more sunlight to be accessible to plants, also through urination, nitrogen gets back into the soil.
36
What is rugosity and why is it important?
Rugosity is the wrinkling of a surface. This is used to describe forest canopy’s. When rugosity is height, there is a variable of canopy heights, and light use is more efficient since all light is being used at different height levels.
37
Which ecosystems have the highest net primary production, which has highest percentage of Earth’s production?
Algal beds and reefs are number one for percentage, making them very productive but they come in low quantities so they do not contribute to very much of the Earth’s Net Production. Tropical forests are second for average NPP as well as the percentage of Earth’s net primary production. The ocean has a very low average net primary production proportional to its % of Earth’s surface, but has the highest percentage of Earth’s net primary production.
38
Define trophic structure, food chain, and trophic level
Trophic structure determined the route that energy flows through the ecosystem, a food chain is the sequence of food transfers from trophic level to trophic level. A trophic level is just one link on a food chain.
39
List the 5 positions of trophic levels in a food chain
Producers (autotrophs): organisms that make organic food molecules from inorganic material.
Primary consumers (herbivores): organisms that eat only producers
Secondary consumers: organisms that eat primary consumers. Ex: small mammals, frogs, or spiders.
Tertiary consumers: organisms that eat secondary consumers. Ex: snake, pike fish.
Quarter consumers: organisms that eat tertiary consumers. Ex: apex predators, hawks, killer whales.
40
What is a detritivore/decomposed?
A consumer that eats detritus, the dead material produced by all trophic levels (ex: plant waste and carrion). Examples of detritivores are earthworms, vultures, but most importantly bacteria and fungi.
41
What are recalcitrances?
Recalcitrances are compounds that refuse to breakdown and stay in their inorganic form. Detritivores cannot use this as energy and instead sinks into sediments as inaccessible energy.
42
What are some of the difficulties of depicting the flow of energy in a food chain?
Omnivore organisms feed at different trophic levels, difficult to determine what level they are. Some animals feed at different trophic levels at different times through their lives,. Matter may pass through an organism more than once, example is that the feces of animal A may be consumed by animal B and at a later time animal A may eat animal B. Some plants feed on animals. Many microorganisms make a living autotrophically and heterotrophically.
43
Define a food web. What are a problem that come with food chains?
Multiple food chains, a network of interconnecting food chains. Provides a detailed information about who eats who, more realistic but complex.
Besides complexity, food webs don’t account for the detritus system, resulting in a larger amount of energy that is accounted for.
44
What is secondary production?
The rate of biomass production by heterotrophic or consumer organisms. Secondary production may refer to all consumers, or a sub-component of consumers in an ecosystem. This production is expressed in the same units as NPP,
45
What is the relationship between primary and secondary production?
In general, ecosystems with high primary production tend to have elevated secondary production.
46
What are the three fundamental efficiencies when referring to energy flow within a trophic level?
Ingestion/consumption efficiency (IE), Assimilation efficiency, Production efficiency
47
Define Ingestion / Consumption efficiency
% of total productivity available at one trophic level that is consumed (ingested) by the trophic level above. For primary consumers, IE is the % of NPP that finds its way into the gut of herbivores. There is generally more plant biomass available than can be eaten, due to plant adaptations.
48
How does ingestion efficiency change in herbivores depending on the environment?
Low efficiency in forests, about 5%, 25% in grasslands, and 50% in phytoplankton dominated communities. The remainder of plant production dies without being eaten and enter the detrital system.
49
How does ingestion efficiency change in regards to secondary consumers, specifically carnivores eating herbivores?
IE ranges from 5-100%. Predators must locate, capture and consume their prey. Prey has adaptations such as camouflage, indigestible adaptations, such as a shell.
50
What is assimilation efficiency?
The fraction of ingested energy that is assimilated (crosses the gut lining into the body) by an organism. Remainder of the energy that is not assimilated is egested as feces. Consumption of plant tissues has an AE of about 30%. Most of the energy is locked up in cellulose and lignin, which are resistant to breakdown.
51
How does assimilation efficiency change for carnivores?
AE for carnivores is generally higher, at around 80% since there is no cellulose or lignin. But many insects still have adaptations such as exoskeletons that cannot be digested.
52
What is the difference between ingestion efficiency and assimilation efficiency?
Ingestion is literally just what proportions can a trophic level consume of the level below. If there is 100% biomass of grass available of bison to eat, and they only eat 30% annually, then their IE would be 30%. Assimilation efficiency would be regarding the nourishment they obtain from the grass. Since plants have lignin and cellulose, it is generally low.
53
Define food quality and how it relates to Assimilation efficiency
Food quality is associated with the Assimilation efficiency since food quality is defined as the ease of assimilating prey. For example, soft fruit with a thin peel has a much higher food quality than say a coconut.
54
Can a consumer improve their assimilation efficiency?
Yes they can through mastication, digestive enzymes, symbiotic relationships, and the length and shape of their guts. All of these would improve AE.
55
Define production efficiency (PE)
Production efficiency is the proportion off the assimilated energy that is converted into new biomass (tissue)- the remainder is largely lost to respiration. The resulting increase in biomass is secondary production. Invertebrates have a high PE of 30 to 40%, losing relatively little energy to respiratory heat.
56
How do endotherm’s and ectotherm’s production efficiency vary?
Endotherms use about 98% of their assimilated energy in maintaining homeostasis. Vertebrate ectotherms divert about 44% of their assimilated energy to secondary production, since less is lost to cellular respiration. However, ectotherms that put more into secondary production, have lower AE as well.
57
How do assimilation efficiency and production efficiency relate?
Since assimilation efficiency is the amount of nutrients you get from what you eat, production efficiency is the process of using that same energy towards new biomass.
58
What is incomplete ingestion, incomplete assimilation, and incomplete transfer of energy into biomass?
Incomplete ingestion represents all of the primary production that cannot be consumed. Incomplete assimilation is that not all ingested energy crosses the gut lining into the organism. Incomplete transfer of energy is energy lost to metabolic activities like respiration, opposed to biomass production like reproducing or growing.
59
What is trophic transfer efficiency and how is it calculated?
Trophic transfer efficiency is the energy available to an upper trophic level and is calculated by multiplying IE x AE x PE. This provides an estimation of the amount of energy that is available to the level above, as we go higher in level, less energy is available at each stage.
60
What is the range and rough average for trophic transfer efficiency? How does it change as we get higher in the food chain?
Energy transfer range between trophic levels is usually around 10%, while the range is anywhere from 1% to 90%. You can multiply trophic transfer efficiency at each level to get the energy available for the next highest level, from the original. Because of this loss in energy, trophic levels in a food chain are FINITE. 5 and 6 are kind of the max.
61
What are some implications for top trophic levels?
Top consumers must be mobile and search for prey over large areas to obtain adequate numbers of prey. They also must have a low abundance since they have access to little energy. This makes them susceptible to extinction.
62
True or false, every ecosystem has a detritus foot chain?
True, also, detrital systems are responsible for the majority of secondary production.
63
How do patterns of energy flow differ in the following four ecosystems? Forest, Grassland, Plankton Community, Stream Community.
Forest: Most energy from NPP goes to dead organic matter, while the rest goes to the grazer system. Most of the energy from NPP in Dead organic matter gets picked up by the decomposed system and then respirated.
Grassland is very similar to Grassland except a little lest energy in the decomposer system.
Plankton community: Much more energy into the grazing system than that of the decomposer system.
Stream community: Much Lower NPP, so arrows leading to Grazer system and dead organic matter look about the same. Besides that, it looks similar to the grassland and Forest ecosystem. A lot of energy comes from the external environment, a level below dead organic matter is called Terrestrial catchment.
64
What is the difference between the grazing food chain and the detrital food chain?
Grazing food chain is created by herbivores that eat autotrophs, and carnivores that eat herbivores. The detrital good chain has a base of detritus as the source of energy, eaten by decomposer herbivores, which are eaten by carnivores.
65
Is primary production more associated with the grazing system or the detrital system? Why is this so?
Detrital system. Since most of the energy produced in the grazing system goes to the detritus food chain, we can infer that more energy production is then prevalent in that food chain. Fun fact: Algae and phytoplankton contribute little Dead organic matter to the detrital system, hence why aquatic communities have a lower amount of energy in the detrital system, and are therefore have more production in the grazing food chain.
66
How does the pyramid of abundance differ between Grassland Ecosystem and a Forested Ecosystem?
Grassland abundance size decreases as you move up the pyramid. Grass is most abundant, then primary consumers, secondary, tertiary, etc. In a Forest, since the size of the primary producers (huge trees) is much larger than that of the primary consumers (small insects), it creates an inverted pattern of abundance between producers and consumers, the rest follows accordingly.
67
Describe how a pyramid of biomass looks in its associated ecosystem: Grassland, Forest, Open Ocean.
Grassland: Looks like a normal pyramid, most biomass is in green plants, then in primary consumers, secondary, etc. Forest is similar to Grassland except most of the biomass is tied up in wood and is mostly unavailable to herbivores, therefore the base of the pyramid is huge, while the level higher is much, much smaller. In an open ocean, we get an INVERTED pattern of Biomass, where the Herbivore level is the largest, followed by producers and then carnivores. This is because the quality of Carbon is much better than that of the others so the producers can support more herbivores than there are producers, extremely efficient.
68
What does an energy flow pyramid always look like?
Energy flow pyramids always look like a pyramid where the bottoms is the largest value, and the top the smallest. Values vary, but they always have a pyramid shape. Remember, that about 10% trophic transfer efficiency energy is available to the level above.
69
How can agriculture meet growing population and carbon problems?
Reducing our ecological footprint by eating less meat. Could feed 10x more people if everyone was vegetarian. 75% of world’s agricultural lands are devoted to feeding animals, not humans. 70% of water withdrawals are for agriculture. Crops that use less energy will reduce greenhouse gas emissions, and water pollution from fertilizers and biocides. Better transportation and storage will result in less food waste.
70
What are some complications that come with living at the top of the food web?
DDT- dichlorodiphenyltrichloroethane is a toxin persistent in the environment because it is resistant to break-down, accumulates in body fat. Also, Mercury levels behave the same way. Both of these have low concentrations in their environment. These toxins increase as you go upwards, exponentially.
71
What are some of the consequences of DDT?
Interference with the formation of egg shells, they become much weaker and tend to break. Some type of falcon nearly went extinct because of DDT. In Otters, at age 5 they can develop mental problems and can’t survive.
72
What does POPs stand for and what effects do they have?
Stands for persistent organic pollutants. In a study of Inuit peoples, their breast milk had concentrations 7x higher that women in southern regions. Some of the effects of POP’s is cancer, reduced immunity, decreased learning ability in children, lower infant birth weights. Fun fact, food products with a high level of these were banned in 1970s.
73
What is the Cold Condensation Theory?
In the tropics, at warm temperatures, POPs vaporize into the air and are carried thousands of kilometres in air currents. If they reach cold environments, they condense and collect in snow and ice. Then in spring when it melts, it enters the arctic food web and become readily available. Anybody getting their water supply from cold regions (mountains) are susceptible to these toxins. Inuits that ate caribou instead of seals had much lower levels of these toxins.
74
What is one way that mercury has entered the ecosystem here in Saskatchewan?
Mercury can escape into the environment through the burning of coal.
75
What are some factors that the Saskatchewan fishing guide warns about Hg levels?
The type of fish that you eat matters for mercury levels. Also the size and age are very important. As fish get larger, they tend to be older, and therefore have been exposed to these toxins much, much longer than others.
76
What did the case study on Albacore Tuna reveal?
13% of the canned tuna that they had sampled had carried levels that were above the maximum level to be sold in stores. So the government has done a poor job in regulating Hg levels that are accessible to the public. However, a person that ate too much tuna, 3-4 cans a day, had mercury levels 4 times the recommended level, and took him a full year for the mercury levels to come back down.
77
What is the reason for high Hg in tuna? Can it be blamed on one source?
Biomagnification of Hg in tuna has always been high since they are so high on the food chain. Burning of coal has made it worse but it can’t be the only thing to blame.
78
Define biogeochemical cycles
Processes by which matter cycles from the living world to the non living physical environment and back again. This is different from energy flow because organisms constantly dissipate energy, they recycle material.
79
What different forms are inorganic Carbon in?
CO2, (.04% of atmospheric gases), H2CO3 (carbonic acid), bicarbonate (HCO3), and carbonate (CO3). Each of these exist in water depending on pH level.
80
For how many years may carbon stay dormant in trees?
Hundreds to thousands of years. Can also be part of detritus for millions of years.
81
What is the largest reservoir of Carbon?
Carbon in the form of CaCO3 (limestone) and fossil fuels in the lithosphere make up the majority of stored carbon.
82
What is carbon concentration in the air, what are its local patterns in a forest?
CO2 is usually at 411mg / L right now in time. In a forest, CO2 levels are higher at midnight since photosynthesis is at its lowest, but also the floor of the forest has the highest concentration because of the grounds slow release of carbon as well as less access to winds.
83
Based on the diagram in week 11, how does the proportion of Carbon change in its annual fluxes? Note, units are Gigatonnes
Most of Carbon is trapped. 6 x 10^7 in carbonate rock, 38,000 Gt in the ocean, 10’000 in fossil fuels, and 1500 in soils and dead organic matter. Surface ocean waters are warmer so they hold less, 920, while vegetation holds 520 and absorbs twice as much as it puts out. Atmosphere holds more than vegetation at 750. The trade off between the atmosphere and the ocean are very similar at 91 and 92.
84
How is carbon returned to water, the atmosphere, and abiotic environment?
Cellular respiration, combustion of wood and fossil fuels, and weathering of limestone.
85
What is the greenhouse effect and is it a natural process?
The greenhouse effect is when radiation is absorbed by the earth’s surface and transmitted back to the atmosphere at LONGER wavelengths. These longer wavelengths are absorbed by atmospheric CO2 and other greenhouse gases and water vapour and then converted to heat. The slows the escape of radiant energy from the atmosphere back into space, and causes additional warming. This is a natural process that has worsened due to human activity, generally beneficial because it insulates the planet from the cold temperatures of outer space.
86
What is the hockey stick effect?
In this class, used to model the effect of greenhouse gases, but generally it is a graph that exponentially grows and looks like a hockey stick.
87
How has atmospheric CO2 and other greenhouse gases such as Methane and Nitrous Oxide increased in concentration? Which now has the highest concentration, which contributes proportionately the worst to the greenhouse effect?
They have all grown exponentially since the late 19th century, start of the industrial revolution. Methane is the most abundant, followed by CO2 and Nitrous Oxide. CO2 is the least bad in regards to its greenhouse effectiveness, Methane is 20x worse than CO2, and Nitrous Oxide is 300x worse than CO2.
88
What are some of the effects that we are facing already from climate change?
Sea level rise, declining arctic sea ice, increase in extremes weather, forest fires, droughts, floods and storms.
89
What is the effect of global warming on regional climates?
Regions are becoming warmer and or drier while other regions are expected to become colder and/or wetter. May lead to mass migration of humans.
Example: the Greenland ice cap provides cold water to the deep Atlantic, warm water flows over it and moderates northern Europe’s climate via the Gulf Stream. If the icecap is lost, these currents may disappear and N.Europe may enter a mini ice age.
90
Why is climate change so difficult on biodiversity?
Many organisms can only live within a small temperature and moisture region, and if the planet changes rapidly, these same organisms may not adapt quick enough. They will be forced to move regions or adapt rapidly. If neither happen they will be eradicated.
Species, except Herptiles (reptile or amphibian) have moved more North to keep within the temperature range.
91
Why should we be most worried about flooding?
Large human populations live in low lying coastal areas (13/20 largest cities in the world). In China, 30 Million people will be displaced with only a .5m rise in sea level. Currently, ocean water levels are rising about 3mm / year, and rates of melting and sea level rise is accelerating. This is happening because as ocean water warms, it expands.
92
How has climate warming effected the prairie?
Bow Glacier has decreased in size, contributes much less to the Bow River. rabies rely on glacial and snow melt in the Rockies. Mean annual temperature both in the summer and the winter has increased. Salinity in Jackfish Lake has increased, as you increase in temperature but not in precipitation, more water is lost to the landscape.
93
What are some solutions to climate change?
Sustainable Urban Planning and Development, Sustainable Lifestyles, Integrated Water Management Across Canada, Sustainable Agriculture, Communities encourage the use of less water (great job Kindersley).
94
What is the largest reservoir for Nitrogen? Why is it that way?
The atmosphere. Makes up 78% of the atmosphere. N2 is very stable since it binds with itself and must be split before it can combine with other elements.
95
What is the most limiting factor in primary producers?
Nitrogen.
96
What are the five steps in the nitrogen cycle?
Nitrogen Fixation, Nitrification, Assimilation, Ammonification, Denitrification.
97
Explain the Nitrogen fixation step of the Nitrogen Cycle
It is the conversion of N2 to NH3, only happens in an oxygen free environment. Certain Cyanobacteria and soil bacteria fix N with the enzyme nitrogenase. Wild plants with symbiotic nitrogen fixers are colonizer of poor soils and fix the soiled through Nitrogen fixation. Diazotrophs are a species that can take N2 in its form and fix it. Heterocyclic are specialized cells that can do this too.
98
Explain the Nitrification step of the Nitrogen Cycle
The conversion of ammonia (NH3) or ammonium (NH4) to Nitrate. This is accomplished by a series of bacteria known as Nitrifiers.
99
Explain the Assimilation step of the Nitrogen Cycle
Plants (via roots), bacteria & algae can absorb NH3, NH4, NO3, and NO2 and incorporate the nitrogen into organic compounds.
100
Explain the Assimilation step of the Nitrogen Cycle
The breakdown of organic nitrogen compounds into ammonia or ammonium. For example, humans do this with protein. When protein is used as energy instead of structure, nitrogen gets broken down and is pissed out as nitrogenous waste and recycled back into the environment. Decomposer are important in the breaking down of nitrogenous waste to ammonium.
101
Explain the Denitrification step of the Nitrogen Cycle
The reduction of nitrate (NO3) to gaseous nitrogen (N2). Denitrifying bacteria complete the cycle by converting NO3 to gaseous N2, and requires a low O2 environment.
102
Every time you get this card, look at the Nitrogen cycle slide in week 11 to learn how the cycle works.
Remember that the nitrogen cycle has two loops in it. One where Nitrogen gets released into the atmosphere as N2, and another where it is assimilated by plants and eaten by animals and then peed out again.
103
Nitrogen Flux Measurements: Explain where Nitrogen exists in the environment proportionately. Units in 10612 g N / Y
Nitrogen is most abundant in the ocean, with a value of 8000, and is recycled internally in the deep ocean or at a lesser extent in the surface waters. Nitrogen can leave to the atmosphere through denitrification or come back through biological fixation. Biological fixation can also bring 140 from the air to land plants, where land plants recycle 1200 within themselves and release less than 200 to the air through denitrification. 100 goes to the atmosphere through human activities.
104
What impact have humans had on the nitrogen cycle?
Rate has grown exponentially. Late in the twentieth century, human sources of fixed nitrogen exceeded nonhuman sources for the first time in history. We fix more Nitrogen synthetically by making fertilizers.
105
What was the process that allowed us to synthesize ammonia?
Called the Haber-Bosch Process, In the presence of an Iron Oxide catalyst, at 200 atmospheric pressure and 450 degrees C, N2 and Hydrogen can make NH3. This allowed us to produce enough fertilizers to feed the worlds enormous population and was a reason for why we could grow to what we are.
106
What happens to fertilizer after its application?
Amount of fertilizers applied often exceed the soils ability to absorb these nutrients, particularly nitrate, which is very water soluble and follows water trails and finds itself into rivers and lakes and stimulates bacteria growth, lowering water quality. Can also enter wells and contaminate ground waters.
107
What is eutrophication?
Nurture enrichment into water. It is when Human sewage, livestock waste, and soil erosion adds nutrients to natural waters. Causes algal bloom and gets people very sick, this is how people died from diarrhea. The city of Toledo had to shut down due to poor water quality.
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What are the effects of eutrophication of fresh waters?
Loss of water quality, anoxia, fish kills, loss of recreational value, most importantly toxins. If cyanotoxins are present, that water cannot be used for anything because it is so deadly.
109
What are some of the problems of having nitrogen in groundwater?
Nitrate concentrations can reach dangerous levels, can give infants blue baby syndrome. Prevents oxygen from binding in red blood cells.
110
True or false: Phosphorus, Carbon,and Nitrogen all have gaseous atmospheric phases in the biosphere?
False, Phosphorus does not. It only exists in the atmosphere as dust.
111
Where is phosphate found in the environment?
Found at very low concentrations in soil and aquatic environments. The reason why it is so slow is because of weathering rock is a slow process that releases phosphorus. Also, phosphate tends to bind with many compounds and become unavailable for biotic uptake. In quantity systems, these bound compounds eventually get locked into sediments. Based on this, phosphorus is often a limiting nutrient. Remember that this was the limiting nutrient in Kenora Ontario research project.
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How does phosphorus cycle through the environment?
2 loops, starting with the much slower one, precipitated phosphates are stuck in rock, when rock is uplifted through tectonic plates, rain weathers rock. Phosphate in the rock goes into the soil, then into the water and back to rock.
The smaller loo starting at when the phosphate is in soil is up taken by organic compounds. These paints that uptake the phosphate are eaten by animals, which die and then go into the detritus system where detrivores decompose the phosphate back into the soil. Though out the whole process it stays in a phosphate form it seems.
113
Phosphates exist in only a few areas of the ecosystem, name how the cycle is proportioned compared to its environment? Note all units are in 10^12 g P / y
Marine sediments are the larger reservoir of P in the biosphere, holding 4 x 10^9. Then the soil comes second, containing 200’00, the ocean with 90’000 and mingle rock containing 10’000. 3000 lives with pants and is internally cycled, but some P can go from the rocks exposed from mining to river flow and out to the ocean. Very little (1) is available in dust transport.
114
What are some of the human impacts that has affected the Phosphorus cycle?
Excess P is carried from agricultural landscapes to surface waters. PO4 binds quickly to soil particles and tends to accumulate in agricultural landscapes, which is starting to saturate the landscape. When these soils AE eroded, they carry P to water-bodies.
115
What has the city of Saskatoon done about their rising Phosphorus levels in the water?
The city has been able to extract phosphorus from the sewage system and resell it as fertilizer. They remove both Phosphorus and Nitrogen. This fertilizer is not water soluble apparently too so it should have more difficulty getting back into the water system.
116
What was the study that Jeff and his team did to reduce Phosphorus in pit lakes that were old mines.
They used put 9 mesocosm’s to help grow algal and bind metals so that Phosphorus and other material would sink faster to the bottom of the pit. When these nutrients bonded, they got heavier as well as stimulating algae, this improved the water quality at a much cheaper cost.
117
What forms is Sulfur in, during the sulfur cycle?
It has gaseous, liquid, and solid phases. This allows it to circulate on a global scale. It is also the least understood cycle as well.
118
What forms are sulfur in when found in the atmosphere?
Atmosphere sulfur is found as SO2, H2S, ad surface particles. These combine with moisture and are removed with precipitation. Self ate may also fall to Earth’s surface as dry deposition through forest fires, volcanic activity, or fossil fuel burning.
Fun Fact: you may have encountered H2S in muddy environment, if you had ever smelled rotten eggs it is mostly likely H2S.
119
What is the connection between atmospheric sulfur and ocean sulfur?
Dimethylsulfide (DMS) is a major biogenic gas that enters the atmosphere from the ocean. It is created from decomposition of plankton in ocean surface waters. DMS is oxidized to sulfate aerosols which are involved in cloud condensation. Since clouds have a pronounced effect on climate by cooling, they may be a partial solution to offset global warming.
120
Talk about the proportions of the Global Sulfur Cycle. All units are in 10^12 g.
The ocean holds the most amount of carbon with 1 x 10^8 while deep oceans hold 12 x 10^8. Beth if settlement holds exactly two times more than deep oceans. Much of sulfur is exchanged into the air from the oceans through volcanoes, atmospheric deposition, sea spray, and biogenic gases. Vegetation and soils hold the most amount on land, while fossil fuels release from the land to the atmosphere. Sedimentary rocks deep below the Earth hold about 3 x more than benthic sediment for the overall largest reserve.
If Jeff asks for the largest pool of sulfur, say sediments. If he asks for the largest environment, say oceans.
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What affect does sulfur have on water systems?
Sulfur acidified water, results in less biodiversity. Animals with calcium shells cannot live because high pH will break it down. Most fish live in the circumneutral pH level of 6.5 - 8. This acidification can come from the burning of fossil fuels that turn into wet deposition and enter the water system.
122
What problem was caused between Canada and the United States in regards to pH level?
High Fossil fuel burning rate in the U.S created a lot of dry disposition of Sulfur that was carried by the air and came to Canada where there were regions of acid sensitivity. An agreement in the late 1980s-early 90s resulted in reductions in sulfur emissions. Sulfur burning in Northern Alberta can come over to Saskatchewan and acidity our lakes. This damage in pH is reversible and have seen lake pH slowly get back closer to neutral ranges.
123
What are the two main components of streams and small rivers? Define them.
Riffles and pools. Riffles are zones of rapids, shallow, and turbulent water. These are erosion along zones where only moderate to large stones (rubble) may remain without being washed downstream. Riffles are zones of INTENSE PRIMARY PRODUCTION by periphyton (algae that grows on rocks) and also of strong secondary production. Primary and secondary production in streams is dependent on the particles at the bottom with sand or silt being the least productive since no organism can attach. Cobble is the best environment for pp and sp.
Pools are zones of slower moving and deeper water where sediments may be deposited. Decomposition dominates in the fine bottom sediments of pools. Pools are zones of low production unless they have access to sunlight.
124
What is the hyporheic zone on a river?
It is the zone between ground water and stream water. Water moves in and out through upwelling and downwelling to mix up the water and exchange nutrients and dissolved organic matter. During low flow conditions, invertebrates will migrate into hyporheic sediments
125
How do you classify stream orders?
A small headwater stream without any tributaries is a first order stream. When two streams of the same order join, the resulting stream becomes one order greater. If a stream joins another stream of lesser order, the largest order number remains the same number.
Head water streams are orders 1-3. Medium sized streams are orders 3-6. Rivers are orders that are larger than 6.
126
Are rivers and streams considered heterotrophic systems? Why or why not?
Particularly, headwater streams are considered heterotrophic systems. For it to be a heterotrophic system, ecosystem respiration must exceed primary production. Large energy and nutrient subsidies enter lotic (rivers and streams) systems from the terrestrial environment. Most of this subsidy is from leaves and woody debris from riparian. Inputs larger than 1 mm are known as coarse particulate organic matter (CPOM) and inputs smaller are known as fine particulate organic matter (FPOM). Inputs smaller than .2 micrometers are know as dissolved organic matter (DOM).
127
What are shredders? Give an example
Shredders are specialized invertebrates that assimilate about 40% of the material that they ingest, the rest is egested as feces back to the stream as FPOM. They eat the biofilm on the leaf. Ex: Tipula Cranefly larva, Gammarus freshwater shrimp, Nemurella stonefly larva.
128
What are collectors and is there a difference between Riffle collectors and Pool collectors?
Collectors are invertebrates that specialize in collecting FPOM through filtering and gathering. They extract from nutrition from microbial laden FPOM. Collectors in Riffles are in areas that can latch onto areas and not be swept by the current. Examples are simulium black fly larva and the Hydropsyche. Pool Inhabitants are much more motile. Ex: Ephemera Burrowing mayfly larva, tubifex oligochaete worm, chironomus midge larva.
129
What are scrapers?
Scrapers are invertebrates that feed on the algae on rock surfaces. Their scraping activities loosen material off rock surfaces and what is not ingested travels downstream as FPOM. They always have adaptations to the fast water. Glossosoma cased caddies is encased in stone for protection, while Heptagenia Mayfly larva flattens itself against the rock in the dead zone.
130
List an invertebrate carnivore that feeds on shredders, collectors, and scrapers. List a vertebrate predator as well.
Invertebrate predator- Cordulegaster dragonfly larva, Sialis Alderfly larva, Glossiphonia Leech.
Vertebrate predators: Large stoneflies, Dobson flies, fish, and salamanders.
131
What effects downstream movement in rivers?
Downstream movement is dependent on both physical and biological retention. Increases in stream flow rate causes a more rapid loss of nutrients from a lotic system. Physical retention is anything that may slo other things down such as leaf packs, logs, etc. Biological retention also affects the velocity of the river since organisms can consume and hold material in one place.
132
What do longitudinal spirals tell us about a river?
The longer the spiral length, the less efficient the system is in RETAINING nutrients. Physical structures help increase this efficiency. Tight spirals are important in retaining nutrients in fast water, caused by abundant debris.
133
What is the river continuum concept (RCC)?
The RCC links stream size, organic matter inputs, the processing of organic matter, and the structuring of invertebrate communities from the headwaters to the most of the lotic system.
134
According to the RCC, what is the Gross primary production to respiration ration (P/R) in Headwater streams, medium size streams, and rivers?
Headwater system is below one because of its lack of exposure to sunlight, can’t grow autotrophs.
In medium size rivers, P/R is above 1 since more sunlight is available and velocity diminishes, greatly increasing the number of habitats that are created. Helps with biodiversity.
In rivers, P/R is below 1 because autotrophic production declines due to turbidity (less clear water) and therefore plants are less productive. River becomes lake like.
135
Where does the RCC apply to? How would it change here?
RCC was created from an Eastern North American POV. Does not transfer here since we have a different environment. We have less input from the environment and most of our rivers have access to sunlight, so compared to the original model, ours would be a couple systems further since our production on average is higher due to sunlight.
136
What does the RCC model tell us?
This model can show us what kind of fish live in different rivers that lead to lakes. Also, it helps us categorizers whether grazers, collectors, or shredders is more productive or not.
137
What are some human influences that affect a river?
Irrigation, transportation, power generation (building dams), flood control, dredging the river for gold, and sewage and waste disposal.
138
What did we learn about the Colorado River in class?
Provides water for 7 states and Mexico, roughly 30 million people. 70% of the water is used for irrigation. Flow has decreased a lot since 1900. Most of this water is used for irrigation in the Sonoran Desert to grow crops, same with Arizona, they grow pistachios. THIS IS NOT SUSTAINABLE. Because water access has declined, Colorado gets first dibs, California now gets less access to this water.
139
What is the most endangered river in Canada?
The south Saskatchewan river.
140
What is channelizing a river?
It is when trenches are dug to create an artificial stream. Most often used to drain wetlands for agriculture purposes. Results in poor water quality that feeds into larger water pools. When channelizing of a river happens, it ruins the biodiversity and the wetlands around it since they don’t get flooded anymore.
141
What are all the different types of lakes that we learned about in this class?
Glacial tarn / cirque, glacial, tectonic, pothole, riverine, volcanic.
142
What are the three thermal structures of a lake?
Epilimnion: warm, well mixed, top layer.
Metallimnion: region of rapid temperature and density change between warm epilimnetic waters and cold hypolimnetic waters.
Hypolimnion: cold, oxygen-poor, dark zone. Lowest level.
143
What seasons do we see no establishment of the water layers?
In spring and fall. Water will be similar throughout as all water mixes.
144
What is the photic zone and the aphotic zone?
Photic zone is the upper lit waters that extend down to 1% of remaining light intestine. This is where photosynthesis and respiration occur. Aphotic Zone is the dark region where only respiration occurs. Compensating point is the point that divides the two zones, it marks the 1% of remaining light.
145
Why do many fish live in the top two temperature zones of a lake?
Many fish like 12 degree Celsius of water, but also, when water is below 12 degree, oxygen in the water becomes less available. So in the spring fish can be caught at the surface because it is the first region to exist in that ideal temperature range.
Note that in the summer, microbes can deplete O2 concentrations in the bottoms two layers by mid summer.
146
What is the Littoral zone of a lake?
Near shore region, extends from shore to a depth where only 1% of light remains on the bottom. Aquatic rooted plants are common here. Providing habitats for many organisms. Littoral zone fish include pike and walleye.
147
What is the Pelagic zone of a lake?
open area above the epilimnion. Home of plankton, phytoplankton, zooplankton, and pelagic fish. All small organisms besides the fish.
148
What is the Benthic zone of a lake?
Benthic zone is the bottom layer below the 1% of available light. This region is often anoxic, but if it is oxic, then invertebrates can become abundant within it.
149
What is the relationship between the size of lake and production?
As the size off the lake gets smaller, production is usually dependent on Littoral one macrophage and benthic algal production. But as the lake gets larger and deeper, the pelagic habitat grows much high because of proportions.
150
In small nutrient rich lakes, phytoplankton contribute a lot to littoral zone’s. Why is this?
Under nutrient rich conditions, phytoplankton can become very abundant and shade-out benthic algae and submerged macrophytes in the littoral zone. Negative relationship between benthic (littoral) production and phytoplankton production.
151
Are lakes normally above the P/R at 1 or below it?
Usually respiration exceeds primary production. Not always though. Accessible phosphorus can change this.
152
What are the three lake status based on phosphorus concentration?
Oligotrophic, mesotrophic, eutrophic. This is in order, and the goes 0-10, 10-30, and 30 + accordingly. Most lakes in Saskatchewan are Eutrophic because of productivity, and because phosphorus from farming had led to higher production, but lower water quality.
153
What are the four regions of the open ocean?
Epipelagic, mesopelagic, bathypelagic, abyssopelagic. This is in order
154
What are the primary producers in the marine ecosystem?
Phytoplankton. However, only 80% of light energy is absorbed in the top 10 m of the water column. Zooplankton are the primary herbivores in this environment too.
155
What are planktons effect on the ocean?
Plankton regenerate nutrient, they are the main pathway that maintains system productivity. Very efficient organisms. Due to a process such as Plankton, the ocean accounts for 50% if carbon fixation.
156
With what organism do Coral reefs have a symbiotic relationship with? What are the benefits to this relationship?
Zoonxanthellae are photosynthetic dinoflagellates (algae) that provide organic substances to the host, specifically glycerol which is needed for the production of coral. In return, they receive shelter and inorganic nutrients from the host. Up to 90% of energy needs of hard corals can be met by the zooxanthellae.
157
What happens when corals get stressed? How does this happen?
When corals get stressed, they lose their zooxanthellae and then start to bleach. This can occur from extreme temperatures, lack of sunlight, acidification of the water. 89% of the great barrier is bleached, the article said 93%.
158
What are the differences between sod grasses and bunch grasses?
Sod grasses are developed on a solid mat above the soil, while bunchgrasses grow in clumps. Other grasses may grow between these clumps.
159
Describe some aspects of short grass prairie and their environment.
Associated with the drier sections of the Canadian Prairie. Annual precipitation is below 350 mm, mean annual temps below 3 degrees, dry summers. They are under 50 cm in height, typically used for ranching. Cut off line for short grass prairie is Kindersley, everything south of it is short, north of it is mixed.
160
Describe some aspects of mixed grass prairie and their environment.
More humid than the short grass prairie but exist in lower mean annual temperatures, results in less water stress. 350-650 mm of precipitation annually. Taller grasses occupy lowlands, shorter grasses occupy higher elevations. Depending on precipitation, short or tall grass will dominate. Most of this land has been cultivated. Found north of Kindersley and curves around it.
161
Describe some aspects of tall grass prairie and their environment.
Majority is found in the U.S. The taller the grass the more precipitation it needs. Moisture is available well into the summer, rain goes into august. It is the most productive. Almost all tall-grass prairie landscapes have been turned into cultivated land. Growth of trees due to lack of fires has also hurt the ecosystem as well, results in less biodiversity.
162
What role does fire have on the prairie?
Naturally occurring forest forest were estimated to happen every 2-3 years. Helped keep tree populations down, and biodiversity up. It sows down any woody vegetation since it takes longer to grow. Too frequent of burns result in losses of biodiversity too. The reason why grass grows back so quick is because half, or more of the biomass is below ground.
163
Talk about Carbon in the grasslands. Specifically carbon pools.
Organic and inorganic carbon is stored in grasslands is a major pool of carbon. Equals 20-25% of all carbon stored in terrestrial ecosystems, but is dependent on climate conditions. Warmer temperatures increase decomposition and reduce solid carbon stocks. Carbon accumulates slowly in the soil, cultivating the land may result in a 50% loss of carbon stocks. May take 50-100 years to restore this carbon.
164
How does root to shoot ratio differ in grassland compared to other biomes?
4.2 root to shoot ratio. This is much higher than all the other biomes except tundra. This is because precipitation is much lower in the grasslands and tundra, and need to spend more energy growing their roots in order to have access to water.
165
Fun Fact:
For given amount of plant biomass, no matter what biome you’re in, they are much more productive proportionately to their biomass.
