D: Biology = Changes in Living Systems 1.5 The Recycling of Matter Flashcards
What is one of the most powerful forces in nature?
A large wildfire
Wildfires release tremendous amounts of energy through dramatic chemical reactions.
What can intense updrafts created by a wildfire lead to?
Winds that can gust up to 160 km/h
These winds can develop like a tornado and hurl flaming logs great distances.
What is a firestorm?
A fire creating its own weather
This phenomenon occurs when a wildfire generates strong updrafts and winds.
Why are wildfires seen as uncontrollable menaces?
They pose significant hazards to industry, homes, public safety, and natural resources
This highlights the importance of wildfire prevention efforts.
What has been a top priority in relation to wildfires?
Preventing wildfires
Efforts include suppression of all wildfires, even smaller ones.
True or False: Preventing and suppressing all wildfires may increase the risk of large destructive fires.
True
Suppressing low-intensity fires can lead to fuel accumulation, increasing the risk of catastrophic fires.
What do low-intensity fires reduce?
The accumulation of fuel
This includes thick layers of pine needles, dead branches, and underbrush.
What is the risk associated with an old forest that has not been subjected to low-intensity burns?
It is more at risk for having a catastrophic fire
Such fires burn with great intensity and spread rapidly over larger areas.
What role do fires play in boreal forest ecosystems?
Fires play an important role in maintaining a healthy and diverse habitat for a variety of plants and animals.
What happens to lodgepole pine trees after a forest fire?
The parent trees may die, but within a few years the blackened landscape is dotted with lodgepole pine seedlings.
What is prescribed burning?
A practice in which forestry personnel deliberately set small, controlled fires under ideal weather conditions.
Why is prescribed burning practiced?
To mimic the historical pattern of more frequent, low-intensity burns that are integral to forest ecology.
How does prescribed burning enhance public safety?
By reducing the amount of combustible material, thus lowering the risk of uncontrolled wildfires.
Energy flows in one direction but matter is recycled. True or False?
True.
What are food chains, food webs, and ecological pyramids models of?
They show how energy moves in only one direction through the trophic levels of an ecosystem.
How is energy from the Sun stored in an ecosystem?
As chemical energy in food at the first trophic level through the process of photosynthesis.
What percentage of chemical energy is passed along to higher trophic levels?
About 10%.
What happens to the remaining chemical energy at each trophic level?
About 90% is used by the organisms and eventually passed into the environment as heat.
Why must energy in an ecosystem be constantly replenished?
Because energy is continually flowing out of the system.
Without the continual input of solar energy, what would happen to the ecosystem?
The ecosystem would shut down.
What role do fires play in boreal forest ecosystems?
Fires play an important role in maintaining a healthy and diverse habitat for a variety of plants and animals.
What happens to lodgepole pine trees after a forest fire?
The parent trees may die, but within a few years the blackened landscape is dotted with lodgepole pine seedlings.
What is prescribed burning?
A practice in which forestry personnel deliberately set small, controlled fires under ideal weather conditions.
Why is prescribed burning practiced?
To mimic the historical pattern of more frequent, low-intensity burns that are integral to forest ecology.
How does prescribed burning enhance public safety?
By reducing the amount of combustible material, thus lowering the risk of uncontrolled wildfires.
Energy flows in one direction but matter is recycled. True or False?
True.
What are food chains, food webs, and ecological pyramids models of?
They show how energy moves in only one direction through the trophic levels of an ecosystem.
How is energy from the Sun stored in an ecosystem?
As chemical energy in food at the first trophic level through the process of photosynthesis.
What percentage of chemical energy is passed along to higher trophic levels?
About 10%.
What happens to the remaining chemical energy at each trophic level?
About 90% is used by the organisms and eventually passed into the environment as heat.
Why must energy in an ecosystem be constantly replenished?
Because energy is continually flowing out of the system.
Without the continual input of solar energy, what would happen to the ecosystem?
The ecosystem would shut down.
What is the moisture content of the atmosphere?
Humidity
Humidity is a measure of the amount of water vapor present in the air.
What happens to hydrocarbon compounds as organic matter in a forest burns?
They are distilled into their constituent parts
This distillation process leads to the creation of various chemical compounds.
What effect does burning organic matter have on soil?
Creates a waxy coating that leads to a waterproof layer
This waterproof layer forms just under the soil surface.
How does a forest fire impact the ability of forests to absorb and hold water?
Reduced ability due to waterproof layer and damaged vegetation
Both factors contribute to diminished water retention in the soil.
What occurs to water flow after heavy precipitation following a forest fire?
Greater portion directed to runoff
This leads to increased soil erosion, especially noticeable on slopes.
How long does it take for surface vegetation to begin returning after a wildfire?
About two years
This recovery time can vary based on environmental conditions.
What happens to the waterproof soil layer after two years post-wildfire?
Begins to break down
As it breaks down, the soil regains its ability to retain moisture.
Why is it important to use less water despite continual recycling?
Difficult to return removed water without quality deterioration
Polluted water reduces the availability of clean water for human use and ecosystems.
What change is being made regarding household toilet water usage?
Switching to toilets that use only 6 L per flush instead of 18 L
This change reflects a growing awareness of water conservation.
What major human activity affects the water cycle?
Deforestation
Deforestation impacts temperature regulation and moisture content in soil.
What role do trees play in the water cycle?
Regulate temperature and moisture content of soil
Trees provide shade, which protects soil from direct sunlight.
What are biogeochemical cycles?
Processes involved in recycling essential elements and compounds
These cycles refer to the exchange between Earth and ecosystems of the elements essential to life.
What does the prefix ‘bio’ in biogeochemical refer to?
Life
What does the prefix ‘geo’ in biogeochemical refer to?
Earth
What does the prefix ‘chemical’ in biogeochemical refer to?
Elements and compounds
What is the primary element that all life on Earth is based on?
Carbon
What do producers take in from the atmosphere to start the carbon cycle?
Carbon dioxide
What is the simplified overall equation for photosynthesis?
Energy + 6 CO₂(g) + 6 H₂O(g) → C₆H₁₂O₆(aq) + 6 O₂(g)
What do living organisms return to the atmosphere during cellular respiration?
Carbon dioxide
What is the simplified overall equation for cellular respiration?
C₆H₁₂O₆(aq) + 6 O₂(g) → 6 CO₂(g) + 6 H₂O + Energy
What are carbon sinks?
Systems that remove more carbon dioxide from the atmosphere than they release
Carbon sinks include forests, peat bogs, and oceans.
What are some examples of carbon reservoirs?
- Fossil fuels
- Animal fossils
- Calcium carbonate reserves in oceans
What is peat?
Deep layers of mosses and plant remains unable to completely decompose due to lack of oxygen
True or False: The carbon cycle is only affected by the processes of photosynthesis and cellular respiration.
False
Fill in the blank: The carbon cycle involves the movement of carbon through various __________.
Reservoirs
What role do producers play in the carbon cycle?
They convert carbon dioxide into energy-rich molecules during photosynthesis.
What is the primary function of cellular respiration?
To convert the chemical energy stored in sugars into usable energy for cells.
What ecosystem is mentioned as having peat bogs?
Alberta
What is the relationship between carbon sinks and atmospheric carbon dioxide?
Carbon sinks absorb more carbon dioxide than they emit.
What type of organisms primarily perform photosynthesis?
Plants and some other organisms
What is the simplified overall equation for cellular respiration?
C₆H₁₂O₆(aq) + 6 O₂(g) → 6 CO₂(g) + 6 H₂O(l) + Energy
What are reservoirs of carbon called?
Carbon sinks
Why are boreal forest ecosystems significant in the carbon cycle?
They are significant carbon sinks due to trees and peat accumulation
What are peat bogs in Alberta called?
Muskeg
How old are some peat bogs in Siberia estimated to be?
At least 10,000 years old
What role do peat bogs play in the carbon cycle?
They absorb huge amounts of carbon, making them top carbon sinks
What happens when peat bogs are drained?
Carbon stored is released as carbon dioxide, becoming a source instead of a sink
Fill in the blank: Ecosystems that remove more carbon dioxide from the atmosphere than they release are called _______.
carbon sinks
True or False: Peat is formed from completely decomposed plant material.
False
What is the primary reason peat remains undecomposed in peat bogs?
Lack of oxygen in water-saturated soil
What is the primary human activity that adds to the accumulation of carbon dioxide in the atmosphere?
Burning of fossil fuels
This activity reverses millions of years of photosynthesis.
How does deforestation impact the carbon cycle?
Eliminates trees that absorb carbon dioxide
This leads to increased atmospheric carbon dioxide levels.
What are the effects of removing trees from an ecosystem?
Increases soil temperature extremes and decreases soil moisture
These changes can significantly alter the microclimate.
What happens to carbon stored in peat bogs if they dry out?
Carbon starts to be released
This release contributes to increased atmospheric carbon levels.
True or False: Wildfires turn a forest from a carbon sink into a carbon source.
True
Burning forests release carbon dioxide into the atmosphere.
What is a significant risk associated with dried-out peat bogs?
They can become a huge fire risk
Large amounts of fuel stored in peat bogs can lead to underground fires.
Why is oxygen essential for living organisms?
It is used in chemical reactions that release energy
Most living things depend on energy from oxidation reactions.
How does photosynthesis contribute to the oxygen cycle?
It produces oxygen, maintaining the atmospheric balance
Cyanobacteria and modern plants are key contributors.
What process balances the oxygen produced by photosynthesis?
Cellular respiration
Energy is released from food molecules in the presence of oxygen.
Fill in the blank: __________ is the process through which organisms extract oxygen from the atmosphere.
Breathing
This involves inhaling oxygen necessary for survival.
What percentage of oxygen do some deep-sea organisms require to improve their ability to absorb nutrients?
15%
This is crucial for their survival and metabolic processes.
What is the role of oxygen in the atmosphere?
Oxygen is crucial for respiration and photosynthesis
Oxygen accounts for a significant part of the atmosphere and is a key component in the oxygen cycle.
What processes are sources for oxygen in ecosystems?
Photosynthesis and cellular respiration
These processes contribute to the cycling of oxygen in ecosystems.
What is the approximate percentage of carbon dioxide in the atmosphere?
0.036%
This highlights the dynamic relationship between carbon and oxygen in the atmosphere.
Name some nutrients that are cycled along with oxygen in ecosystems.
- Sulfur
- Phosphorous
- Nitrogen
These nutrients are part of the larger nutrient cycling systems in ecosystems.
Where does human impact on the oxygen cycle primarily occur?
In the ozone layer, 10 km to 50 km above Earth’s surface
This region is crucial for filtering ultraviolet radiation from the sun.
What forms ozone in the atmosphere?
High-energy radiation from the Sun breaking apart oxygen molecules
This process produces free oxygen atoms that can react to form ozone.
What compounds can destroy ozone in the atmosphere?
Chlorofluorocarbons (CFCs)
These pollutants migrate to the ozone layer and lead to ozone depletion.
True or False: The ozone layer is getting thicker due to human activities.
False
The ozone layer is thinning due to pollutants, which is a cause for concern.
What is the significance of the ozone layer for Earth?
It protects Earth from the Sun’s powerful ultraviolet radiation
This protection is essential for the health of living organisms.
What is the impact of wildfires on the oxygen cycle?
Wildfires release energy and can lead to the exposure of minerals that deplete atmospheric oxygen
The aftermath of wildfires can also contribute to erosion.
Fill in the blank: Ozone is a molecule comprised of _______ atoms of oxygen.
three
Ozone (O3) is formed when oxygen molecules react with free oxygen atoms.
What is the role of decomposers in the oxygen cycle?
Decomposers break down organic matter, contributing to nutrient cycling
This process can take years, while other processes can accomplish similar tasks in seconds.
Why is nitrogen critically important to life?
It is a key component in biologically important molecules, such as protein and DNA.
What percentage of the atmosphere is composed of nitrogen?
78%
Why can’t organisms use atmospheric nitrogen directly?
Nitrogen gas (N₂) is non-reactive; it takes a lot of energy to break up N₂ molecules.
What do plants rely on to convert nitrogen gas into usable forms?
Bacteria
What are the forms of nitrogen that plants can use?
Ammonia (NH₃), nitrate ions (NO₃⁻), and nitrite ions (NO₂⁻).
What process allows nitrogen gas to be converted into ammonia?
Nitrogen fixation
What types of bacteria are involved in nitrogen fixation?
Bacteria found in the soil and in nodules on the roots of legumes.
What is the process called that converts ammonia into nitrates and nitrites?
Nitrification
What do denitrifying bacteria do?
They convert nitrates back into nitrogen gas.
What is the process of converting nitrates back into nitrogen gas called?
Denitrification
What natural event can convert nitrogen gas into nitrates?
Lightning
How do human activities primarily affect the nitrogen cycle?
By adding large amounts of nitrogen compounds to water or air.
What can excessive fertilizers applied to crops cause?
Harmful algal blooms in nearby rivers or streams.
How do emissions from smokestacks and automobile exhaust affect the nitrogen cycle?
They produce oxides of nitrogen that can combine with rainwater to form acid rain.
What effect do wildfires have on nitrogen in organic molecules?
They break down organic molecules into simpler forms like nitrates and ammonia.
What is a negative outcome of wildfires regarding nitrogen?
A portion of nitrogen is returned to the atmosphere.
What is a positive outcome of wildfires on soil nitrogen levels?
Nitrogen-containing substances become more abundant in the soil after a fire.
What effect does a wildfire have on soil temperature and acidity?
It makes the soil warmer and less acidic.
Which flowering plants thrive in post-fire habitats due to their nitrogen-fixing capabilities?
Wildflowers, especially lupins.
Fill in the blank: The process of converting nitrogen gas into usable forms for plants is known as _______.
nitrogen fixation
What is nitrogen fixation?
The process of converting nitrogen gas into ammonia
Nitrogen fixation is a crucial step in the nitrogen cycle, enabling plants to utilize atmospheric nitrogen.
What are nitrifying bacteria?
A type of soil bacteria that converts ammonia into nitrates and nitrites
Nitrifying bacteria play a key role in soil fertility and the nitrogen cycle.
Define nitrification.
The process of converting ammonia into nitrates or nitrites
Nitrification is an essential part of the nitrogen cycle that helps in plant nutrient uptake.
What are denitrifying bacteria?
A type of soil bacteria that converts nitrates in soil into nitrogen gas, releasing this gas to the atmosphere
Denitrifying bacteria are important for returning nitrogen to the atmosphere.
What is denitrification?
The process of converting nitrates in the soil into nitrogen gas
Denitrification helps to regulate nitrogen levels in the soil and is a crucial process in the nitrogen cycle.
What is nitrogen fixation?
The process of converting nitrogen gas into ammonia
Nitrogen fixation is a crucial step in the nitrogen cycle, enabling plants to utilize atmospheric nitrogen.
What are nitrifying bacteria?
A type of soil bacteria that converts ammonia into nitrates and nitrites
Nitrifying bacteria play a key role in soil fertility and the nitrogen cycle.
Define nitrification.
The process of converting ammonia into nitrates or nitrites
Nitrification is an essential part of the nitrogen cycle that helps in plant nutrient uptake.
What are denitrifying bacteria?
A type of soil bacteria that converts nitrates in soil into nitrogen gas, releasing this gas to the atmosphere
Denitrifying bacteria are important for returning nitrogen to the atmosphere.
What is denitrification?
The process of converting nitrates in the soil into nitrogen gas
Denitrification helps to regulate nitrogen levels in the soil and is a crucial process in the nitrogen cycle.
