Knowt
U1
Predator: Organism that eats his prey (Ex: egret ----> fish; the arrow represents where the energy and nutrients are going/ the flow of energy during predation)
Competition for limited resources
Grasshopper ---> Lizard; multiple lizards are competing for food (the grasshopper) which is competition within the same species
Competition between species: different species competing for the same resources
Competition for limited resources between species is stronger when species have similar niches (ways of which they use resources around them)
Example: Whale/Zebra (different niches, do not compete)
Similar niche species can coexist without dying out
Example: Lionfish
Similar niche to larger native fish
Out-compete the larger native fish for food
“Complete exclusion”
Native fish population goes down
Overall biodiversity goes down
How can all these different species co-exist when they have similar niches?
Resource Partitioning - using the resources in different ways, places or at different times (can reduce the negative impact of competition on survival)
Resource Partitioning reduces competition and promotes biodiversity
One can resource partition by space (organisms eating at different heights), food variance and time (eats grass earlier than another organism)
Healthy and Stable Ecosystem: high species richness & lots of different species in one community
When thinking of a solution pertaining to food webs and the effects of anthropogenic disturbances, for example, remember to think about the PROS, CONS, and UNINTENDED CONSEQUENCES
Symbiosis: different species living in close association with one another
Mutualism (both benefit)
Inside coral lives algae; coral gets products of photosynthetic algae and algae have a home
Commensalism (one organism benefits and one is not harmed)
Barnacles on a whale; Plankton rich environment; plenty of food; the whale is not harmed
Parasitism (one organism benefits and the other is harmed)
Tapeworm inside intestine feeding off nutrients and stealing nutrients from the host animal
Unit 1.2: Terrestrial Biomes
Biome: It is an area of the planet that can be classified according to its climate and the organisms that have adapted to that particular location/climate
Individual organism goes into a population, all of the different populations put together is the community, and when you add all of the abiotic factors and such, it is an ecosystem
No exact boundaries like country borders
Some fuzzy transition areas
Several different classification systems
One of the guiding principles of biomes is noticing where in terms of latitude they’re located
Our nine terrestrial biomes:
Taiga (boreal forest)
North America, Asia and Europe (up on the map)
Located in high altitudes between 50 and 60 degrees, this biome is characterized by low precipitation, low species diversity, and low annual temperatures that promote some permafrost. Not located in the southern hemisphere
Organisms
A rather low species richness
Trees dominated by evergreen conifers (e.g. spruce and fir) with adaptations of drought-resistant needle-like leaves
Most animals are medium-to-small size (e.g., rabbits, rodents, mink, and lynx) with few large (e.g. caribou, wolves, bears, and moose); insulating feathers/fur and migration are useful adaptations
Natural resources and human use/impact
Climate (short growing season) and poor soil quality limits agriculture (slow decomposition)
A huge source of lumber and pulpwood (world’s main source of industrial wood)
Also used for mining for natural gas and oil
Climate change warming parts of boreal forest
Temperate rainforest
Pacific Northwest, some in Asia, and Europe (up on the map)
This biome has warm summers and cool winters and occurs where there is adequate rainfall to support an evergreen forest
Organisms
Robust species richness
Trees dominated by large evergreen trees (e.g. spruce, cedar, and fir) as well as epiphytes (e.g. mosses, lichens, and ferns)
Typical animals are squirrels, deer, elk, and numerous birds, reptiles, and amphibians
Natural resources and human use/impact
Mild winters and summers cause slow decomposition of needles (relatively poor soil)
Long growing season and significant precipitation = very large trees
A large producer of lumber and pulpwood
Threatened by logging
Especially critical to saving are to “old-growth” (never logged) forests
Temperate seasonal forests
Eastern US, Asia, Eastern coast of Australia
This biome has wide variations in temperature and precipitation and vegetation comprising four vertical layers: mature canopy, juvenile canopy, shrubs, and herbs. Experiences warm summers and cold winters
Organisms
Strong species richness
Common animals are deer, bears, and many small mammals and birds
Trees dominated by deciduous trees (e.g. oak, hickory, maple) with a dense canopy
Natural resources and human use/impact
Warmer temperatures promote decomposition (and thus soil fertility - humus)
Higher productivity than more northern biomes
Lost to logging, clearing land for agriculture and growth of cities
Relationship between deciduous trees in a temperate seasonal forest and soil fertility: Deciduous trees in a temperate seasonal forest drop their leaves annually. Decomposers break down this leaf litter and add nutrients into the soil, thus increasing soil fertility.
Tropical rainforests
Amazon rainforest, Africa, SE Asia
Organisms
Very high species
Very productive (NPP)
Thick vegetation with heavy canopy cover, so plant adaptations help compete for sunlight
⅔ of terrestrial species on the planet are in this biome
Natural resources and human use/impact
Hot and wet conditions promote high decomposition
Soilless fertile than you would think because dense vegetation takes it up quickly
Deforestation for agriculture, industrial expansion, and human population growth
The soil is quickly depleted nutrients when the forest is removes
Shrubland (chaparral)
Coastal regions: along California on the west coast of the US, all around the Mediterranean, some in Australia
One of the rarest biomes, it is found primarily in coastal regions and experiences hot, dry summers and cool, moist winters
Mild winters with high precipitation and dry, hot summers
Thin, not-so-fertile soil (heavy leaching by winter rains)
Frequent natural fires
Shrubs with dry and fire adaptations
Organisms: Abundant deer, lizards, and jackrabbit
Threats: Human development and livestock grazing
Temperate grassland
Found in the middle of large landmasses or continents. The two major areas are the prairies in North America and the steppe which straddles Europe and Asia. The majority of this biome is found between 40° and 60° north or south of the Equator.
Known regionally as prairie, pampas, veld, of the steppe, this biome is largely devoid of trees and has large seasonal variability in temperatures but relatively low precipitation
Carnivores, like lions and wolves, are also found in temperate grasslands. Other animals of this region include: deer, prairie dogs, mice, jackrabbits, skunks, coyotes, snakes, foxes, owls, badgers, blackbirds, grasshoppers, meadowlarks, sparrows, quails, and hawks
The biggest impact that humans have on grasslands is by developing open areas for farming or urban development. Such development is prevalent because grasslands are generally level areas with little need for major work to develop the land.
Resources in the temperate grasslands include wheat, coal, oil, corn, livestock, gas, and oats. Water and timber are the two primary resources that one can find in the chaparral.
Savana
Savannas are generally found between the desert biome and the rainforest biome. They are mostly located near the equator. The largest savanna is located in Africa. Nearly half of the continent of Africa is covered with savanna grasslands.
With warm temperatures and seasonal rainfall, this biome consists of a mixture of grasses and sparse trees and is found within tropical and subtropical latitudes
Humans impact the Grassland Savanna by lessening the area of the land by making new space for industrialization. The trees and animals have less space to be so the population decreases with the land, making everything smaller.
In the African Savanna, there are many natural resources but overall there are, soil, and for agriculture, lumber, minerals, and oil.
Desert
With dry, treeless landscapes receiving less than 25 centimeters of rainfall annually, this biome may be characterized by extreme diurnal temperature variations
Most deserts that cover the earth's surface are located in the eastern hemisphere of the globe. However, there are a few in the United States in Nevada, New Mexico, Texas, and littler ones in other states.
Animals include fennec foxes, dung beetles, Bactrian camels, Mexican coyotes, sidewinder snakes, and thorny devil lizards.
Humans have impacted the desert biome in that they have polluted the atmosphere. This affects all biomes, including the desert. People have also drilled for many fossil fuels, such as oil, in the desert. This causes pollution and is harmful to the animals living near the oil wells.
Groundwater leeches ore minerals and deposits them in areas near the water table, concentrating the minerals so ore can be mined. Among the many valuable metallic minerals found in deserts are deposits of gold, silver, iron, lead-zinc ore, and uranium in the southwestern deserts of the United States and Australia.
Tundra
A frozen, treeless, desert located between 60 and 70 degrees latitude, this biome is characterized by sparse vegetation and months of no sunlight
The oil, gas, and mining industries can disrupt fragile tundra habitats. Drilling wells can thaw permafrost, while heavy vehicles and pipeline construction can damage soil and prevent vegetation from returning. This activity also increases the risk of toxic spills.
Animals found in the tundra include the musk ox, the Arctic hare, the polar bear, the Arctic fox, the caribou, and the snowy owl. Many animals that live in the tundra, like the caribou and the semipalmated plover, migrate to warmer climates during the winter.
Energy Resources of the tundra include oil, natural gas, and uranium. Examples of mineral tundra resources are iron ore, copper, zinc, nickel, diamonds, gemstones, and precious metals. Sand, rock, and gravel are also mined from the Arctic tundra for industrial use.
Low NPP and species richness (biodiversity)
Does not have high ecosystem stability
Oil and natural gas exploration
Permafrost
Melting with climate change, producing greenhouse gases (positive feedback loop)
Climate graph (climatogram/climatograph): a visual representation of the climate of a biome
Unit 1.3: Aquatic Biomes
Freshwater biomes include streams, rivers, ponds, and lakes. These freshwater biomes are a vital resource for drinking water
Streams and Rivers:
Flowing water ecosystem
Conditions and organisms vary with:
Upstream/river vs. downstream river
Amount of canopy cover might change the temp
Depth, velocity, discharge/volume of water
Turbidity (cloudiness)
Even salinity as it moves into the ocean (St. Johns river becomes the salt marsh)
Floodplain: the area on either side of a river that will flood
More fertile because water floods up, deposits some of that nutrient-rich sediment and then goes back (so we may have lots of agriculture in floodplains)
Human impacts
Pollution
Nutrient pollution (eutrophication)
Acid mine drainage
Sediment pollution from construction/erosion (making the water more turbid and reducing photosynthesis)
Diversion of water for human use
Dams
Sediment buildup in reservoir
Habitat fragmentation
Differences in rivers/stream physical characteristics inform the kind of organisms that live there
The flow of a river and types of organisms that live there influence each other
Lakes and Ponds
Standing water ecosystem
Depth affects light penetration (photosynthesis)
Littoral Zone: rooted vegetation, lots of productivity and biodiversity
Limnetic Zone: open part of lake/pond
Profundal Zone: if the limnetic zone is deep enough, some lakes/ponds have it, where light is not present, a different community than found in the littoral zone
Drinking-Water
Marine Biomes
Marine biomes include oceans, coral reefs, marshland, and estuaries. Algae in marine biomes supply a large portion of the Earth’s oxygen, and also take in carbon dioxide from the atmosphere
The global distribution of nonmineral marine natural resources, such as different types of fish, varies because of some combination of salinity, depth, turbidity, nutrient availability and temperature
Marine Biomes: Oceans
Depth and light
Nutrient availability
Salinity
All of the above creates a variety of different communities
Open Ocean
Tidal
Benthic: bottom
Pelagic: open part of the ocean
Aphotic Zone: no light, chemosynthesis
Marine Biomes: Coral Reefs
It is a Benthic habitat (shallow/light)
Corals with symbiotic algae (gives color)
Secrete calcium carbonate (CaCo3) from the whole reef structure which builds up over time
High biodiversity
Threats that are linked to climate change: Coral bleaching (occurs when sea surface temperatures become too hot, the coral spit out their symbiotic algae and if that goes on for too long they starve to death because the algae were what was giving them all those nutrients, but when they kicked those out they risked dying) and ocean acidification (affects coral reefs and any organism that has a shell) which affects the rate at which these organisms can build their shells out of calcium carbonate
Marine Biomes: Marshland
It is a Coastal wetland (wetland: an area where the soil is saturated with water at least part if not all of the year)
Brackish (not salt, not fresh, somewhere in between) water
The organisms that live there have to be adapted to rising and falling tides
Dominated by grasses
Human Benefits:
Filter water before it reaches open water; water flow slows and sediments can settle
Nutrients absorbed by vegetation (N & P)
Marine Biomes: Estuaries
Nursery grounds of the ocean
Where flowing freshwater stream/river meets the ocean
Brackish water
Tidal cycles affect depth and salinity (organisms their have to have adapted to those changes)
Very fertile ecosystem
High NPP and species richness
A safe place for larval stages of fish and shellfish
Marine Biomes: Algae
‘Battery of the ocean”
Plankton serves as the basis of marine food webs
Phytoplankton
Zooplankton
Drift, moved by current/tides
Gives a lot of our oxygen
Takes in carbon dioxide too (this in light of climate change is good)
Biogeochemical Cycles depict the movement of atoms between sources and sinks; they are called “cycles” because the matter is always conserved; they facilitate the acquisition and transfer of energy into useable forms; humans have disrupted these cycles
Unit 1.4: The Carbon Cycle: the movement of carbon atoms between sources and sinks
Some of the reservoirs in which carbon compounds occur in the carbon cycle hold those compounds for long periods of time
The inorganic carbon cycle is controlled by geologic processes and is critical to the stability of Earth’s climate over long timescales
Dissolved carbon ultimately is gonna be used by shelled organisms to build their shells
Step 1: Carbon enters the atmosphere as carbon dioxide from respiration (breathing) and combustion (burning).
Step 2: Carbon dioxide is absorbed by producers (life forms that make their own food e.g. plants) to make carbohydrates in photosynthesis. These producers then put off oxygen.
Step 3: Animals feed on the plants. Thus passing the carbon compounds along the food chain. Most of the carbon these animals consume however is exhaled as carbon dioxide. This is through the process of respiration. The animals and plants then eventually die.
Step 4: The dead organisms (dead animals and plants) are eaten by decomposers in the ground. The carbon that was in their bodies is then returned to the atmosphere as carbon dioxide. In some circumstances, the process of decomposition is prevented. The decomposed plants and animals may then be available as fossil fuel in the future for combustion.
Some of the reservoirs in which carbon compounds occur in the carbon cycle hold these compounds for short periods of time
Plant and animal decomposition have led to the storage of carbon over millions of years
The burning of fossil fuels quickly moves that stored carbon into atmospheric carbon, in the form of carbon dioxide
Name of the process that takes carbon out of the atmosphere and moves it into vegetation: photosynthesis
Unit 1.5: The Nitrogen Cycle: the movement of nitrogen atoms between sources and sinks
The major reservoir for nitrogen is the atmosphere (78% of the atmosphere is nitrogen)
It is this inorganic, molecular, abiotic molecule of nitrogen gas
Step 1: Nitrogen fixation: where atoms of molecular nitrogen gas are converted to ammonia; process in which atmospheric nitrogen is converted into a form of nitrogen (primarily ammonia-NH3) that is available by uptake by plants and that can be synthesized (assimilated) into plant tissue (Nitrogen Fixation: N2 ----> NH3 (ammonia))
Step 2: Animals eat the plant and excrete waste, (or the rabbit dies) which is decomposed returning nitrogen to the soil to be taken up by plants
Most of the reservoirs in which nitrogen compounds occur in the nitrogen cycle hold those compounds for relatively short periods of time (unlike the Phosphorus cycle which holds it for a long time)
Human Disruptions to the Nitrogen Cycle
Runoff of fertilizers and livestock waste = Excess nitrogen in aquatic ecosystem = eutrophication
Combustion of gasoline releases NOx which is an ingredient needed for the formation of harmful ozone (photochemical smog)
Less erosion = Less runoff = less nutrient enrichment = less algal blooms
Unit 1.6: The Phosphorus Cycle: The movement of phosphorus atoms between sources and sinks
Step 1: Rock Weathering (breaks down) & releases phosphorus into the soil
Step 2: Now it is in the abiotic component of the ecosystem, then plants take up the phosphorus now that it is in the soil and assimilate it into organic compounds (phosphates in DNA) and use it to build plant tissues
Step 3: Animals eat plant and excrete waste which returns Phosphorus to the soil
Step 4: Phosphorus can runoff from the soil in the ocean where it can SLOWLY be incorporated into sedimentary rock
Rock weathers - it is a cycle
Big takeaways from the Phosphorus Cycle: it happens really slowly
The major reservoirs of phosphorus are rock and sediments that contain phosphorus-bearing minerals
There is no atmospheric component in the phosphorus cycle, and the limit this imposes on the return of phosphorus from the ocean to land make phosphorus naturally scarce in aquatic and many terrestrial ecosystems
Human Disruptions to the Phosphorus Cycle:
In undistributed ecosystems, phosphorous is the limiting factor in biological systems
To solve that problem, humans add fertilizer containing phosphorus, which runs off the land. Phosphate stimulates the growth of algae, which consume large amounts of dissolved oxygen during decomposition, potentially suffocating fish and other marine animals, This is known as eutrophication
Unit 1.7: The Hydrologic (Water) Cycle
Processes and Interactions
The hydrologic cycle, which is powered by the sun, is the movement of water in its various solid, liquid, gaseous phases between sources and sinks
The oceans are the primary reservoir of water at the Earth’s surface, with ice caps and groundwater acting as much smaller reservoirs
Making connections
Climate change intensifies the hydrologic cycle because as air temperatures increase, more water evaporates into the air
Warmer air can hold more water vapor, which can lead to more intense rainstorms, extreme flooding
Warmer water intensifies hurricanes and severe tropical storms
Warmer climates melt land ice causing sea levels to rise
Unit 1.8: Primary Productivity
Primary Productivity is the rate at which solar energy is converted into organic compounds via photosynthesis over a unit of time
Productivity is measured in units of energy per unit area per unit time (e.g., kcal/m^2/yr)
Productivity: “battery” that drives the rest of the food webs in most ecosystems
“Rate” of energy/area/time via photosynthesis
There is a connection between productivity and overall biodiversity of species richness; productivity in desert/tropical rainforest might influence the biodiversity or species richness
Gross Primary Productivity (GPP) and Net Primary Productivity (NPP):
Gross primary productivity is the total rate of photosynthesis in a given area
Net primary productivity is the rate of energy storage by photosynthesizers in a given area after subtracting the energy lost to respiration
Gross means everything
Sunlight hits the grass and makes GPP (products of photosynthesis) and the vast majority of that is used back by the plant for its own cellular respiration
After energy is lost through cellular respiration, what is left over is the NPP
This amount of organic compounds can be turned into tissues for the plant for it to grow
NPP = GPP minus cellular respiration
NPP drives the rest of the food web!
Unit 1.9: Trophic Levels
In terrestrial and near-surface marine communities, energy flows from the sun to producers in the lowest trophic level and then upward to higher trophic levels
The living things in the biosphere are decomposing waste and that connects the biosphere with the rest of the biogeochemical cycles (carbon cycle, nitrogen cycle, sulfur cycle, phosphorus cycle, water cycle)
Why does this trophic level diagram have a pyramid shape?
That has to do with the energy flow; more about this in unit 10
Unit 1.10: Energy Flow and the 10% Rule
Energy decreases as it flows through an ecosystem
Every time an organism eats another organism that energy moves up but some energy is lost due to the second law of Thermodynamics
The 10% rule approximates that in the transfer of energy from one trophic level to the next, only about 10% of the energy is passed on
First Law of Thermodynamics: energy cannot be created or destroyed; it can only be changed from one form to another
Second Law of Thermodynamics: whenever energy is transformed, there is a loss of energy through the release of heat
Unit 1.11: Food Chains and Food Webs
A food web is a model of an interlocking pattern of food chains that depicts the flow of energy and nutrients in two or more food chains
Positive and negative feedback loops can each play a role in food webs. When one species is removed from or added to a specific food web, the rest of the food web can be affected
Food Chain:
Disturbances within communities include invasive species, poaching, logging, etc
If crickets decreased, frogs would decrease, grass would then increase, mice would increase and the influence of the others are unclear
Trophic Levels:
Predator: Organism that eats his prey (Ex: egret ----> fish; the arrow represents where the energy and nutrients are going/ the flow of energy during predation)
Competition for limited resources
Grasshopper ---> Lizard; multiple lizards are competing for food (the grasshopper) which is competition within the same species
Competition between species: different species competing for the same resources
Competition for limited resources between species is stronger when species have similar niches (ways of which they use resources around them)
Example: Whale/Zebra (different niches, do not compete)
Similar niche species can coexist without dying out
Example: Lionfish
Similar niche to larger native fish
Out-compete the larger native fish for food
“Complete exclusion”
Native fish population goes down
Overall biodiversity goes down
How can all these different species co-exist when they have similar niches?
Resource Partitioning - using the resources in different ways, places or at different times (can reduce the negative impact of competition on survival)
Resource Partitioning reduces competition and promotes biodiversity
One can resource partition by space (organisms eating at different heights), food variance and time (eats grass earlier than another organism)
Healthy and Stable Ecosystem: high species richness & lots of different species in one community
When thinking of a solution pertaining to food webs and the effects of anthropogenic disturbances, for example, remember to think about the PROS, CONS, and UNINTENDED CONSEQUENCES
Symbiosis: different species living in close association with one another
Mutualism (both benefit)
Inside coral lives algae; coral gets products of photosynthetic algae and algae have a home
Commensalism (one organism benefits and one is not harmed)
Barnacles on a whale; Plankton rich environment; plenty of food; the whale is not harmed
Parasitism (one organism benefits and the other is harmed)
Tapeworm inside intestine feeding off nutrients and stealing nutrients from the host animal
Unit 1.2: Terrestrial Biomes
Biome: It is an area of the planet that can be classified according to its climate and the organisms that have adapted to that particular location/climate
Individual organism goes into a population, all of the different populations put together is the community, and when you add all of the abiotic factors and such, it is an ecosystem
No exact boundaries like country borders
Some fuzzy transition areas
Several different classification systems
One of the guiding principles of biomes is noticing where in terms of latitude they’re located
Our nine terrestrial biomes:
Taiga (boreal forest)
North America, Asia and Europe (up on the map)
Located in high altitudes between 50 and 60 degrees, this biome is characterized by low precipitation, low species diversity, and low annual temperatures that promote some permafrost. Not located in the southern hemisphere
Organisms
A rather low species richness
Trees dominated by evergreen conifers (e.g. spruce and fir) with adaptations of drought-resistant needle-like leaves
Most animals are medium-to-small size (e.g., rabbits, rodents, mink, and lynx) with few large (e.g. caribou, wolves, bears, and moose); insulating feathers/fur and migration are useful adaptations
Natural resources and human use/impact
Climate (short growing season) and poor soil quality limits agriculture (slow decomposition)
A huge source of lumber and pulpwood (world’s main source of industrial wood)
Also used for mining for natural gas and oil
Climate change warming parts of boreal forest
Temperate rainforest
Pacific Northwest, some in Asia, and Europe (up on the map)
This biome has warm summers and cool winters and occurs where there is adequate rainfall to support an evergreen forest
Organisms
Robust species richness
Trees dominated by large evergreen trees (e.g. spruce, cedar, and fir) as well as epiphytes (e.g. mosses, lichens, and ferns)
Typical animals are squirrels, deer, elk, and numerous birds, reptiles, and amphibians
Natural resources and human use/impact
Mild winters and summers cause slow decomposition of needles (relatively poor soil)
Long growing season and significant precipitation = very large trees
A large producer of lumber and pulpwood
Threatened by logging
Especially critical to saving are to “old-growth” (never logged) forests
Temperate seasonal forests
Eastern US, Asia, Eastern coast of Australia
This biome has wide variations in temperature and precipitation and vegetation comprising four vertical layers: mature canopy, juvenile canopy, shrubs, and herbs. Experiences warm summers and cold winters
Organisms
Strong species richness
Common animals are deer, bears, and many small mammals and birds
Trees dominated by deciduous trees (e.g. oak, hickory, maple) with a dense canopy
Natural resources and human use/impact
Warmer temperatures promote decomposition (and thus soil fertility - humus)
Higher productivity than more northern biomes
Lost to logging, clearing land for agriculture and growth of cities
Relationship between deciduous trees in a temperate seasonal forest and soil fertility: Deciduous trees in a temperate seasonal forest drop their leaves annually. Decomposers break down this leaf litter and add nutrients into the soil, thus increasing soil fertility.
Tropical rainforests
Amazon rainforest, Africa, SE Asia
Organisms
Very high species
Very productive (NPP)
Thick vegetation with heavy canopy cover, so plant adaptations help compete for sunlight
⅔ of terrestrial species on the planet are in this biome
Natural resources and human use/impact
Hot and wet conditions promote high decomposition
Soilless fertile than you would think because dense vegetation takes it up quickly
Deforestation for agriculture, industrial expansion, and human population growth
The soil is quickly depleted nutrients when the forest is removes
Shrubland (chaparral)
Coastal regions: along California on the west coast of the US, all around the Mediterranean, some in Australia
One of the rarest biomes, it is found primarily in coastal regions and experiences hot, dry summers and cool, moist winters
Mild winters with high precipitation and dry, hot summers
Thin, not-so-fertile soil (heavy leaching by winter rains)
Frequent natural fires
Shrubs with dry and fire adaptations
Organisms: Abundant deer, lizards, and jackrabbit
Threats: Human development and livestock grazing
Temperate grassland
Found in the middle of large landmasses or continents. The two major areas are the prairies in North America and the steppe which straddles Europe and Asia. The majority of this biome is found between 40° and 60° north or south of the Equator.
Known regionally as prairie, pampas, veld, of the steppe, this biome is largely devoid of trees and has large seasonal variability in temperatures but relatively low precipitation
Carnivores, like lions and wolves, are also found in temperate grasslands. Other animals of this region include: deer, prairie dogs, mice, jackrabbits, skunks, coyotes, snakes, foxes, owls, badgers, blackbirds, grasshoppers, meadowlarks, sparrows, quails, and hawks
The biggest impact that humans have on grasslands is by developing open areas for farming or urban development. Such development is prevalent because grasslands are generally level areas with little need for major work to develop the land.
Resources in the temperate grasslands include wheat, coal, oil, corn, livestock, gas, and oats. Water and timber are the two primary resources that one can find in the chaparral.
Savana
Savannas are generally found between the desert biome and the rainforest biome. They are mostly located near the equator. The largest savanna is located in Africa. Nearly half of the continent of Africa is covered with savanna grasslands.
With warm temperatures and seasonal rainfall, this biome consists of a mixture of grasses and sparse trees and is found within tropical and subtropical latitudes
Humans impact the Grassland Savanna by lessening the area of the land by making new space for industrialization. The trees and animals have less space to be so the population decreases with the land, making everything smaller.
In the African Savanna, there are many natural resources but overall there are, soil, and for agriculture, lumber, minerals, and oil.
Desert
With dry, treeless landscapes receiving less than 25 centimeters of rainfall annually, this biome may be characterized by extreme diurnal temperature variations
Most deserts that cover the earth's surface are located in the eastern hemisphere of the globe. However, there are a few in the United States in Nevada, New Mexico, Texas, and littler ones in other states.
Animals include fennec foxes, dung beetles, Bactrian camels, Mexican coyotes, sidewinder snakes, and thorny devil lizards.
Humans have impacted the desert biome in that they have polluted the atmosphere. This affects all biomes, including the desert. People have also drilled for many fossil fuels, such as oil, in the desert. This causes pollution and is harmful to the animals living near the oil wells.
Groundwater leeches ore minerals and deposits them in areas near the water table, concentrating the minerals so ore can be mined. Among the many valuable metallic minerals found in deserts are deposits of gold, silver, iron, lead-zinc ore, and uranium in the southwestern deserts of the United States and Australia.
Tundra
A frozen, treeless, desert located between 60 and 70 degrees latitude, this biome is characterized by sparse vegetation and months of no sunlight
The oil, gas, and mining industries can disrupt fragile tundra habitats. Drilling wells can thaw permafrost, while heavy vehicles and pipeline construction can damage soil and prevent vegetation from returning. This activity also increases the risk of toxic spills.
Animals found in the tundra include the musk ox, the Arctic hare, the polar bear, the Arctic fox, the caribou, and the snowy owl. Many animals that live in the tundra, like the caribou and the semipalmated plover, migrate to warmer climates during the winter.
Energy Resources of the tundra include oil, natural gas, and uranium. Examples of mineral tundra resources are iron ore, copper, zinc, nickel, diamonds, gemstones, and precious metals. Sand, rock, and gravel are also mined from the Arctic tundra for industrial use.
Low NPP and species richness (biodiversity)
Does not have high ecosystem stability
Oil and natural gas exploration
Permafrost
Melting with climate change, producing greenhouse gases (positive feedback loop)
Climate graph (climatogram/climatograph): a visual representation of the climate of a biome
Unit 1.3: Aquatic Biomes
Freshwater biomes include streams, rivers, ponds, and lakes. These freshwater biomes are a vital resource for drinking water
Streams and Rivers:
Flowing water ecosystem
Conditions and organisms vary with:
Upstream/river vs. downstream river
Amount of canopy cover might change the temp
Depth, velocity, discharge/volume of water
Turbidity (cloudiness)
Even salinity as it moves into the ocean (St. Johns river becomes the salt marsh)
Floodplain: the area on either side of a river that will flood
More fertile because water floods up, deposits some of that nutrient-rich sediment and then goes back (so we may have lots of agriculture in floodplains)
Human impacts
Pollution
Nutrient pollution (eutrophication)
Acid mine drainage
Sediment pollution from construction/erosion (making the water more turbid and reducing photosynthesis)
Diversion of water for human use
Dams
Sediment buildup in reservoir
Habitat fragmentation
Differences in rivers/stream physical characteristics inform the kind of organisms that live there
The flow of a river and types of organisms that live there influence each other
Lakes and Ponds
Standing water ecosystem
Depth affects light penetration (photosynthesis)
Littoral Zone: rooted vegetation, lots of productivity and biodiversity
Limnetic Zone: open part of lake/pond
Profundal Zone: if the limnetic zone is deep enough, some lakes/ponds have it, where light is not present, a different community than found in the littoral zone
Drinking-Water
Marine Biomes
Marine biomes include oceans, coral reefs, marshland, and estuaries. Algae in marine biomes supply a large portion of the Earth’s oxygen, and also take in carbon dioxide from the atmosphere
The global distribution of nonmineral marine natural resources, such as different types of fish, varies because of some combination of salinity, depth, turbidity, nutrient availability and temperature
Marine Biomes: Oceans
Depth and light
Nutrient availability
Salinity
All of the above creates a variety of different communities
Open Ocean
Tidal
Benthic: bottom
Pelagic: open part of the ocean
Aphotic Zone: no light, chemosynthesis
Marine Biomes: Coral Reefs
It is a Benthic habitat (shallow/light)
Corals with symbiotic algae (gives color)
Secrete calcium carbonate (CaCo3) from the whole reef structure which builds up over time
High biodiversity
Threats that are linked to climate change: Coral bleaching (occurs when sea surface temperatures become too hot, the coral spit out their symbiotic algae and if that goes on for too long they starve to death because the algae were what was giving them all those nutrients, but when they kicked those out they risked dying) and ocean acidification (affects coral reefs and any organism that has a shell) which affects the rate at which these organisms can build their shells out of calcium carbonate
Marine Biomes: Marshland
It is a Coastal wetland (wetland: an area where the soil is saturated with water at least part if not all of the year)
Brackish (not salt, not fresh, somewhere in between) water
The organisms that live there have to be adapted to rising and falling tides
Dominated by grasses
Human Benefits:
Filter water before it reaches open water; water flow slows and sediments can settle
Nutrients absorbed by vegetation (N & P)
Marine Biomes: Estuaries
Nursery grounds of the ocean
Where flowing freshwater stream/river meets the ocean
Brackish water
Tidal cycles affect depth and salinity (organisms their have to have adapted to those changes)
Very fertile ecosystem
High NPP and species richness
A safe place for larval stages of fish and shellfish
Marine Biomes: Algae
‘Battery of the ocean”
Plankton serves as the basis of marine food webs
Phytoplankton
Zooplankton
Drift, moved by current/tides
Gives a lot of our oxygen
Takes in carbon dioxide too (this in light of climate change is good)
Biogeochemical Cycles depict the movement of atoms between sources and sinks; they are called “cycles” because the matter is always conserved; they facilitate the acquisition and transfer of energy into useable forms; humans have disrupted these cycles
Unit 1.4: The Carbon Cycle: the movement of carbon atoms between sources and sinks
Some of the reservoirs in which carbon compounds occur in the carbon cycle hold those compounds for long periods of time
The inorganic carbon cycle is controlled by geologic processes and is critical to the stability of Earth’s climate over long timescales
Dissolved carbon ultimately is gonna be used by shelled organisms to build their shells
Step 1: Carbon enters the atmosphere as carbon dioxide from respiration (breathing) and combustion (burning).
Step 2: Carbon dioxide is absorbed by producers (life forms that make their own food e.g. plants) to make carbohydrates in photosynthesis. These producers then put off oxygen.
Step 3: Animals feed on the plants. Thus passing the carbon compounds along the food chain. Most of the carbon these animals consume however is exhaled as carbon dioxide. This is through the process of respiration. The animals and plants then eventually die.
Step 4: The dead organisms (dead animals and plants) are eaten by decomposers in the ground. The carbon that was in their bodies is then returned to the atmosphere as carbon dioxide. In some circumstances, the process of decomposition is prevented. The decomposed plants and animals may then be available as fossil fuel in the future for combustion.
Some of the reservoirs in which carbon compounds occur in the carbon cycle hold these compounds for short periods of time
Plant and animal decomposition have led to the storage of carbon over millions of years
The burning of fossil fuels quickly moves that stored carbon into atmospheric carbon, in the form of carbon dioxide
Name of the process that takes carbon out of the atmosphere and moves it into vegetation: photosynthesis
Unit 1.5: The Nitrogen Cycle: the movement of nitrogen atoms between sources and sinks
The major reservoir for nitrogen is the atmosphere (78% of the atmosphere is nitrogen)
It is this inorganic, molecular, abiotic molecule of nitrogen gas
Step 1: Nitrogen fixation: where atoms of molecular nitrogen gas are converted to ammonia; process in which atmospheric nitrogen is converted into a form of nitrogen (primarily ammonia-NH3) that is available by uptake by plants and that can be synthesized (assimilated) into plant tissue (Nitrogen Fixation: N2 ----> NH3 (ammonia))
Step 2: Animals eat the plant and excrete waste, (or the rabbit dies) which is decomposed returning nitrogen to the soil to be taken up by plants
Most of the reservoirs in which nitrogen compounds occur in the nitrogen cycle hold those compounds for relatively short periods of time (unlike the Phosphorus cycle which holds it for a long time)
Human Disruptions to the Nitrogen Cycle
Runoff of fertilizers and livestock waste = Excess nitrogen in aquatic ecosystem = eutrophication
Combustion of gasoline releases NOx which is an ingredient needed for the formation of harmful ozone (photochemical smog)
Less erosion = Less runoff = less nutrient enrichment = less algal blooms
Unit 1.6: The Phosphorus Cycle: The movement of phosphorus atoms between sources and sinks
Step 1: Rock Weathering (breaks down) & releases phosphorus into the soil
Step 2: Now it is in the abiotic component of the ecosystem, then plants take up the phosphorus now that it is in the soil and assimilate it into organic compounds (phosphates in DNA) and use it to build plant tissues
Step 3: Animals eat plant and excrete waste which returns Phosphorus to the soil
Step 4: Phosphorus can runoff from the soil in the ocean where it can SLOWLY be incorporated into sedimentary rock
Rock weathers - it is a cycle
Big takeaways from the Phosphorus Cycle: it happens really slowly
The major reservoirs of phosphorus are rock and sediments that contain phosphorus-bearing minerals
There is no atmospheric component in the phosphorus cycle, and the limit this imposes on the return of phosphorus from the ocean to land make phosphorus naturally scarce in aquatic and many terrestrial ecosystems
Human Disruptions to the Phosphorus Cycle:
In undistributed ecosystems, phosphorous is the limiting factor in biological systems
To solve that problem, humans add fertilizer containing phosphorus, which runs off the land. Phosphate stimulates the growth of algae, which consume large amounts of dissolved oxygen during decomposition, potentially suffocating fish and other marine animals, This is known as eutrophication
Unit 1.7: The Hydrologic (Water) Cycle
Processes and Interactions
The hydrologic cycle, which is powered by the sun, is the movement of water in its various solid, liquid, gaseous phases between sources and sinks
The oceans are the primary reservoir of water at the Earth’s surface, with ice caps and groundwater acting as much smaller reservoirs
Making connections
Climate change intensifies the hydrologic cycle because as air temperatures increase, more water evaporates into the air
Warmer air can hold more water vapor, which can lead to more intense rainstorms, extreme flooding
Warmer water intensifies hurricanes and severe tropical storms
Warmer climates melt land ice causing sea levels to rise
Unit 1.8: Primary Productivity
Primary Productivity is the rate at which solar energy is converted into organic compounds via photosynthesis over a unit of time
Productivity is measured in units of energy per unit area per unit time (e.g., kcal/m^2/yr)
Productivity: “battery” that drives the rest of the food webs in most ecosystems
“Rate” of energy/area/time via photosynthesis
There is a connection between productivity and overall biodiversity of species richness; productivity in desert/tropical rainforest might influence the biodiversity or species richness
Gross Primary Productivity (GPP) and Net Primary Productivity (NPP):
Gross primary productivity is the total rate of photosynthesis in a given area
Net primary productivity is the rate of energy storage by photosynthesizers in a given area after subtracting the energy lost to respiration
Gross means everything
Sunlight hits the grass and makes GPP (products of photosynthesis) and the vast majority of that is used back by the plant for its own cellular respiration
After energy is lost through cellular respiration, what is left over is the NPP
This amount of organic compounds can be turned into tissues for the plant for it to grow
NPP = GPP minus cellular respiration
NPP drives the rest of the food web!
Unit 1.9: Trophic Levels
In terrestrial and near-surface marine communities, energy flows from the sun to producers in the lowest trophic level and then upward to higher trophic levels
The living things in the biosphere are decomposing waste and that connects the biosphere with the rest of the biogeochemical cycles (carbon cycle, nitrogen cycle, sulfur cycle, phosphorus cycle, water cycle)
Why does this trophic level diagram have a pyramid shape?
That has to do with the energy flow; more about this in unit 10
Unit 1.10: Energy Flow and the 10% Rule
Energy decreases as it flows through an ecosystem
Every time an organism eats another organism that energy moves up but some energy is lost due to the second law of Thermodynamics
The 10% rule approximates that in the transfer of energy from one trophic level to the next, only about 10% of the energy is passed on
First Law of Thermodynamics: energy cannot be created or destroyed; it can only be changed from one form to another
Second Law of Thermodynamics: whenever energy is transformed, there is a loss of energy through the release of heat
Unit 1.11: Food Chains and Food Webs
A food web is a model of an interlocking pattern of food chains that depicts the flow of energy and nutrients in two or more food chains
Positive and negative feedback loops can each play a role in food webs. When one species is removed from or added to a specific food web, the rest of the food web can be affected
Food Chain:
Disturbances within communities include invasive species, poaching, logging, etc
If crickets decreased, frogs would decrease, grass would then increase, mice would increase and the influence of the others are unclear
Trophic Levels:
When you think of biomes, they come in two major categories: terrestrial and aquatic. Biomes are categorized by the climate (temperature and precipitation) and the biomass (plants and animals) living in them. Due to Earth's tilt, the sun's distribution of energy varies, and this difference is what allows scientists to classify certain regions as biomes. For the major biomes, we classify them based on factors such as yearly rainfall and temperature. AP Environmental Science emphasizes key terms such as environmental conditions, , , and throughout this unit.
Cycles
Every biome relies on natural cycles to move matter from one form to another. The rate and intensityof these processes can help in biome classification. The major cycles we are going to study are the carbon, nitrogen, phosphorus, and hydrologic cycles. Since Earth is a closed system, one which recycles matter rather than losing it, these cycles are essential to understanding our planet. Here are the major topics pertaining to each cycle:
:
Nitrogen and Phosphorus Cycles: Large Scale Farming, Growth and Development
Water Cycle: ,
Ecosystem Interactions
Ecosystems build food chains and require constant interactivity with other species and surrounding environments. Since resources are limited, adaptation and evolution are required to sustain oneself and survive.
Species Interactions
: 😀-😀
: 😀-😐
: 😀-😟
Predator and Prey: 😀-😟
Trophic levels
In any ecosystem, we can follow the flow of energy from one trophic level to another. Like a tier chart, trophic levels show distribution of consumption similar to a food chain and this corresponding energy output. As a rule, it takes a lot more energy to create an organism in a 3rd or 4th trophic level than something at the bottom. Here is a diagram to help us better visualize the movement of energy.
In conclusion, Unit One examines the elementary of Earth's functions and how these simple concepts help the planet's natural functions occur properly.
Key Terms to Review (13)
: Biodiversity refers to the variety of living organisms in a particular ecosystem or on Earth as a whole. It includes diversity within species, between species, and of ecosystems.
: The carbon cycle is the movement of carbon atoms between living organisms (plants and animals), the atmosphere (as carbon dioxide), bodies of water (as dissolved carbon dioxide), and fossil fuels (as stored carbon).
: Clean water access refers to the availability of safe and uncontaminated water for human use and consumption. It means having access to water that is free from pollutants, pathogens, and harmful substances.
: Climate change refers to long-term shifts in temperature and weather patterns on a global scale. It is primarily caused by human activities, such as burning fossil fuels and deforestation, leading to an increase in greenhouse gas concentrations in the atmosphere.
: Commensalism is a type of symbiotic relationship between two different species where one organism benefits while the other remains unaffected. The benefiting organism uses the presence of the other for resources like shelter or transportation without causing harm.
: Conservation refers to the sustainable management and protection of natural resources, including land, water, plants, animals, and ecosystems. It aims to maintain biodiversity, preserve habitats, and ensure the long-term well-being of both human and non-human species.
: Environmental conditions refer to the physical factors that influence an organism's survival and well-being in its habitat. These factors include temperature, humidity, light levels, soil composition, and availability of food and water.
: The hydrologic cycle, also known as the water cycle, refers to the continuous movement of water on, above, and below the Earth's surface. It involves processes such as evaporation, condensation, precipitation, and runoff.
: Mutualism is a type of symbiotic relationship between two different species where both organisms benefit from each other's presence. They rely on each other for resources like food, shelter, protection, or reproduction.
: The nitrogen cycle is the process by which nitrogen is converted between its various chemical forms in the environment. It involves nitrogen fixation, nitrification, assimilation, ammonification, and denitrification.
: Parasitism is a type of symbiotic relationship where one organism, called the parasite, benefits at the expense of another organism, called the host. The parasite relies on the host for resources and can harm or weaken it.
: The phosphorus cycle involves the movement of phosphorus through rocks, water bodies, soil, and living organisms.
: Water pollution refers to the contamination of water bodies, such as rivers, lakes, and oceans, by harmful substances or pollutants. This can include chemicals, sewage, oil spills, and other waste materials that degrade water quality and harm aquatic life.