Ecology - Grade 9 Biology
Ecology - Grade 9 Biology
Intro to Ecology
Terms:Â
An ecosystem- is a geographic area where plants, animals and other organisms, weather and landscapes work together to form a bubble of life.Â
Biotic factors: include plants, animals and other organisms.Â
Tide pools- contain seaweed, a kind of algae that uses photosynthesis to create food.
Also, depending on the changing level of the ocean water
Biomes- are a large section of land, sea or atmosphere
Forests, ponds, reefs, tundra
Canopies- ecosystems at the top of the rainforest
Tall, thin trees such as fig grow in search of sunlightÂ
Epiphytes- other plants in the canopy ecosystem
Understory- ecosystem under the canopy ecosystem
Delicate coral reef- an ecosystem in the south pacific at risk due to rising ocean temps. And decrease sanityÂ
InterdependenceÂ
Organisms and their environment are interdependentÂ
Every organism relies on other organisms to surviveÂ
Everything depends on something elseÂ
Levels of organization
Study of ecology ranges from the study of an individual organism to the study of the entire plant as the followingÂ
Individual
Population
Community
Ecosystem
Biome
Biosphere
Species
A group of individuals similar to one another that can breed and create fertile offspring
Population
Organisms of one species that interbreed and live together within a defined areaÂ
Examples
Herd of sheep
Flock of geeseÂ
Colony of ants
Culture of bacteriaÂ
Sleuth of BearsÂ
Brood of chickensÂ
Pack of dogs
Communities
Groups of populations comprised many species that live together in a defined area
EcosystemÂ
Combination of the communities and the physical (nonliving) environmentÂ
Is all living and nonliving factors in a particular placeÂ
Can be large and small
Rotting log
Koi pond
Lake
Clump of dirt
Field
Old maple tree
Bog marsh
BiomeÂ
A large area that has a particular climateÂ
Particular species of plants and animals that live thereÂ
TundraÂ
Rainforest
Desert
A large group of many ecosystemsÂ
BiodiversityÂ
Variety of organismsÂ
Organisms genetic differencesÂ
Ecosystems in which they occurÂ
Ecological diversityÂ
Different ecosystems in a regionÂ
Species diversityÂ
Different species within certain ecosystemsÂ
Tropical rainforests have the highest biodiversity of all biomesÂ
Factors that affect ecosystemsÂ
Abiotic
Nonliving factorsÂ
Soil
Pollutants
Natural disasters
Climate
Biotic factors
Living factorsÂ
plants and animals
Biotic and abiotic both determine the survival of growth of individual organisms and ultimately the ecosystemsÂ
HabitatÂ
Where particular populations liveÂ
Include biotic and abiotic factorsÂ
How do ecosystems form?Â
Constantly changingÂ
SuccessionÂ
Progression of species of replacement over timeÂ
Ecosystems evolvingÂ
Typically slowÂ
Natural disasters or human disturbances can make sudden changesÂ
Primary successionÂ
Occurs when no soil previously existed is called thisÂ
The first species to populate the are called pioneer speciesÂ
Secondary successionÂ
Occurs in areas where soil exitsÂ
But has been damaged or disturbedÂ
Forest fire - exampleÂ
Nutrient cyclesÂ
Biogeochemical cyclesÂ
The matter is neither created nor destroyed
Can be transformed and passed on
How carbon, nitrogen and phosphorus pass from the physical environment to living organismsÂ
About themÂ
Bio-life Â
Geo-earthÂ
Chemical-elements and moleculesÂ
3 biogeochemical essential cyclesÂ
Water cycle
Carbon cycle
Nitrogen cycleÂ
Materials to recycle they have to changes/transform statesÂ
Death and decay contribute to the cycles
Animals and plants die
Bacteria other decomposers break them down in raw elementsÂ
Can be absorbed by plants and passed on to animalsÂ
Water cycleÂ
All living things need water to survive
Moves betweenÂ
OceanÂ
Atmosphere
Land
By cycling from water vapour to liquid water
EvaporationÂ
Liquid water returns to the atmosphere (vaporizers)
TranspirationÂ
Evaporation of water from plantsÂ
Both occur during the daytime when the sun heats up the atmosphere
   CondensationÂ
Atmosphere cools
Water vapour in the air condenses to form cloudsÂ
   PrecipitationÂ
Water droplets that form cloudsÂ
Become large enoughÂ
Droplets fall to the earthÂ
Informs ofÂ
RainÂ
Sleet
Snow
   PercolationÂ
When water returns to earth some is absorbed by plants through their rootsÂ
Other seeps into the soil to become groundwater
   Runoff
Surface water found on landÂ
That eventually carries back to a lake or oceanÂ
Water cycle diagramÂ
Carbon cycleÂ
CarbonÂ
Is an essential element for all living thingsÂ
Is found inÂ
Living tissuesÂ
Rocks
Atmosphere
Ocean
Less than 1 % is found on earth is in the carbon cycleÂ
Carbon dioxideÂ
Which is in the air is or dissolved in water is used by photosynthesizingÂ
PlantsÂ
AlgaeÂ
BacteriaÂ
 As raw materials to build organic molecules such as glucoseÂ
Ways (3) carbon can return to air or waterÂ
RespirationÂ
All living organisms undergo cellular respiration
Use oxygen to break down foodÂ
CO2 is a byproduct of the reaction (exhaled)
ErosionÂ
Marine organisms use it to make sheetsÂ
calcium carbonate
When they die the calcium carbonate breaks downÂ
CO forms and returns to the atmosphereÂ
CombustionÂ
When carbon returns to the atmosphere through combustion or burning fossil fuels
Carbon is locked beneath the earthÂ
Dead organisms sediment may gradually transform by heat
And pressure into fossil fuelsÂ
This process of fossil fuels releases CO2Â
Creates greenhouse gases
Nitrogen cycleÂ
Makes up 78% of the atmosphereÂ
Most organisms are unable to use it in this form
Bacteria in the soil is very importantÂ
Can use atmospheric nitrogen
Fix into compounds usable by other living thingsÂ
Organisms need nitrogen to build proteins and nucleic acids
Nitrogen fixationÂ
Bacteria combine nitrogen from the atmosphere with hydrogenÂ
To make ammonia (NH3) in the soilÂ
AmmonificationÂ
Production of ammonia by bacteria during the decay of organic matter
NitrificationÂ
Production of nitrates and nitrites from ammonia (NO3)
Bacteria are responsible for nitrificationÂ
Plants can use nitrites and nitrates to make proteinsÂ
AssimilationÂ
Absorption of nitrogen into organic compounds by plantsÂ
Absorbed through rootsÂ
DenitrificationÂ
Conversion of nitrate to nitrogen gasÂ
Which is released back into the atmosphere
Phosphorus cycleÂ
Is necessary to build DNA moleculesÂ
Also RNA
Not very common in the biosphere and does not enter the atmosphereÂ
Locked into the land or waterÂ
Is found in rocks and minerals in the soilÂ
Rock gradually wear down phosphorus is released into soil or waterÂ
When organisms dieÂ
Decomposers in the soil or water break them down into raw elementsÂ
Including phosphorus which can then be reusedÂ
When plants absorb phosphate from soilÂ
Can be passed along from plants/producers to other trophic levels
Nutrient limitationÂ
The amount that is available directly affects the primary productivity of an ecosystem
Primary productivityÂ
The rate at which producers produce energyÂ
Limited nutrientÂ
Sometimes ecosystems are limited by a single nutrient that is very scarce or cycles slowlyÂ
FertilizersÂ
Are so popularÂ
They contain 3 important nutrientsÂ
NitrogenÂ
PhosphorusÂ
PotassiumÂ
By using this farmers can ensure that there are enough nutrients
Their corps grow to their fullest potential
Earthâs sphereÂ
Any time matter can occupy one of the four spheres that make up the earth
Lithosphere - solid earthÂ
Atmosphere - gases (the air)
Hydrosphere - all waterÂ
Biosphere - all lifeÂ
BiosphereÂ
The lithosphere, hydrosphere, atmosphere are abiotic spheresÂ
Are found on other planets including earthÂ
Earth has fourth called the biosphere
No other planet in the solar system is known to have thisÂ
The biosphere is the living surface of the earthÂ
Is not separate from abiotic spheresÂ
Many life forms are foundÂ
Underground
WaterÂ
AtmosphereÂ
Energy transfer in the biosphere
All living things in here needÂ
SpaceÂ
WaterÂ
NutrientsÂ
To surviveÂ
Nutrients are stored as energyÂ
Energy is continuously cycled by mean of the food chainÂ
A food chain shows how each living thing gets foodÂ
How energy is transferred from one organism to anotherÂ
A diagram to show what it looks like
Food chains vs food webs
AÂ food chain is a linear flow of energy through an ecosystem
A food web shows multiple food chains interconnected in an ecosystemÂ
Multiple energy pathsÂ
Food chains and food webs represent the transfer of energy in a communityÂ
Trophic levelsÂ
In ecology, this level is a position that an organism occupies in a food chainÂ
Energy moves through food webs from one trophic level to the nextÂ
First Trophic Level: Â ProducersÂ
organisms that make their own food through photosynthesis (plant, algae, cyanobacteria)
Second Trophic Level: Primary Consumers
animals cannot make their own food â they eat producers
called herbivores (plant-eaters)
Third Trophic Level: Secondary ConsumersÂ
animals that eat primary consumers
called carnivores (meat-eaters) and omnivores (eat both animals and plants)
Fourth Trophic Level: Tertiary ConsumersÂ
animals at the top level of the food chain
called top carnivores but can be omnivores as well
The end of the food chainÂ
Decomposers
Organisms that break down dead plants and animals
Puts nutrients back into the soil â energy for producers
Examples: Â bacteria, fungi (mushrooms)
Detritivores
a type of decomposer
decomposers like bacteria and fungi don't eat their food, they break it down.
detritivores eat large amounts of decaying material and excrete nutrients.
Examples: millipedes, dung beetles, earthworms, slugs, snails
Grassland food web
Toxins in food chainsÂ
Each time an organism eats another organism, it gains that organism's energy and nutrients.  Unfortunately, it also gains any toxins that might be stored in that organism's cells.
BioaccumulationÂ
the increase in the concentration of a toxin, such as a pesticide, in an individual organism.
Biomagnification- the increase in the concentration of a toxin in a food chain.Â
toxins accumulate in living things at the top of the food chain when they eat infected organisms lower in the food chain.
Ecological pyramidsÂ
The sun and ecosystemsÂ
The fuel for an ecosystem is energy from the sun.
Light energy is used by green plants in the process of photosynthesis to make chemical energy.
Chemical energy is passed up the trophic levels in a food chain.Â
Energy transfer in food chainsÂ
The greatest amount of energy is found at the 1st trophic level. They are the first organisms to use the energy of the sun.
As one organism eats another, some energy is used for survival and some energy is lost as heat to the environment.
Energy Flows In as Sunlight and Out as Heat
Ecological pyramidsÂ
An ecological pyramid helps us visualize the transfer of energy between the trophic levels in a food chain.
There are 3 major types of ecological pyramids:
Pyramids of numbersÂ
A pyramid of numbers shows the relative number of organisms at each stage of a food chain
Pyramids of numbersÂ
A pyramid of numbers can have various shapes. The width of each block should represent the number of organisms.
Pyramid of biomassÂ
A pyramid of biomass shows the total mass of organisms at each stage of a food chain.
Pyramid of energyÂ
This pyramid compares the amount of energy trapped at each stage of the food chain.
Pyramid of energy - 10%
As one organism eats another, 10% of energy passes from one trophic level to the next up the food chain.Â
Since there is less energy moving up the food chain, the population size of organisms at higher trophic levels decreases.
Interactions in ecosystems
Biotic factors in an ecosystem include all living thingsÂ
And the interactions among those living thingsÂ
Interactions define the ecological niche of speciesÂ
What it feeds onÂ
What it eatsÂ
How it behavesÂ
Examples of interactions among living thingsÂ
SymbiosisÂ
Predation
CompetitionÂ
Interactions - symbiosisÂ
Is the interaction between two different organisms living in a close physical relationship
Example - sea anemones and hermit crabsÂ
Sea anemones hitchhike on the back of hermit crabs
Scoring a ride across the seabed and extending their tentacles to est the crabâs leftoversÂ
In return, the anemones fend off hungry octopusesÂ
The other predators use their barbed tentaclesÂ
Types of symbiosisÂ
Mutualism
A relationship where both species benefit from the interaction
Example - sea anemones and hermit crabs,Â
Insects and flowers (pollination)
ParasitismÂ
A relationship where one species benefits(the parasite)
The other is harmed (the host) by the interactionÂ
For example - mosquitos (the parasite) sucks the blood of humans (the host)
CommensalismÂ
A relationship where one species benefits
The other is unaffected (no benefit or harm) by the interaction
Example- egrets (benefits) and the cattle (unaffected)
Remora (benefits) and sharks (unaffected)Â
InteractionsÂ
PredationÂ
Occurs when one organism consumes another organism for foodÂ
The organism eaten is called prey
Organism consuming prey is called predatorÂ
Carnivorous plants - venus fly trapÂ
Affects insects with its flowerlike reddish colour and ripe fruity smellÂ
Insects seek the nectarÂ
It will inevitably touch the highly sensitive hairs on the leaves causing the trap to snap shut at lightning speedÂ
CompetitionÂ
Occurs when two or more organisms complete for the same resource such asÂ
FoodÂ
Water
Mates
Shelter
Example - sarcastic fringeheadÂ
Lives in a small area on the ocean floor where resources for food and space are scarce
When an intruder invades that space,Â
the fringehead attacks fearlessly and aggressively
Photosynthesis and cellular respiration
Energy flow in ecosystems
2 processes that drive energy flow in ecosystems
Photosynthesis
Converts light energy into chemical energy and stores it as food
Cellular respirationÂ
Release stored chemical energy as food
The reverse process of photosynthesis
PhotosynthesisÂ
Occurs in green plants
AlgaeÂ
Some bacteriaÂ
Green plants have an organelle called a chloroplast
It contains chlorophyll which traps light energy from the sunÂ
Carbon dioxide enters in through small openings called stomataÂ
Carbon dioxide, water and light react to make a sugar called glucoseÂ
Some glucose is used to feed that plant and some are stored for later useÂ
During chemical reaction, oxygen is released into the air through stomataÂ
Photosynthesis equationsÂ
Cellular respirationÂ
Occurs in all organismsÂ
Cells break down stored energy (glucose) and release useable forms of energy for body movementÂ
Body heatÂ
ReproductionÂ
Etc.Â
Chemical reactions occur in the mitochondria of cellsÂ
Stored sugar is converted into carbon dioxideÂ
WaterÂ
Chemical energy (ATP)
Carbon dioxide is put back into the atmosphere to be used againÂ
Photosynthesis vs Respiration
Products (ending materials) of one process are the reactants (starting materials) of the otherÂ
Population LimitsÂ
Population and habitatsÂ
PopulationÂ
All individuals of one species that are in a specific area at a certain time
HabitatÂ
In an environment in which a population lives and gets its need metÂ
Food
Shelter
Reproduction
Etc.
What influences population size?
Abiotic factorsÂ
Influence where species can live
Are determined byÂ
Temp.
Soil
Light
SalinityÂ
Etc
Biotic factorsÂ
Influence a species successÂ
Are determined by competition for resources
Food
Water
Mates
IntraspecificÂ
With members of their own speciesÂ
InterspecificÂ
Also with other speciesÂ
Competition in populationsÂ
Is the demand for resourcesÂ
FoodÂ
MatesÂ
WaterÂ
Etc
Intraspecific is competition for mates in different speciesÂ
Interspecific is competition for food in the same speciesÂ
Limiting factorsÂ
Population canât keep growing forever
Once the population is too big for its environmentÂ
The limiting factors regulate its sizeÂ
ExamplesÂ
Food and water supplyÂ
Mates
Predation/competitionÂ
DiseaseÂ
Sunlight
Space (to live and hide)
TemperatureÂ
Natural disastersÂ
Population densityÂ
Is to measure the number of organisms that make p populations in a defined areaÂ
Density-dependent factorsÂ
Population becomes too large for its environmentÂ
High densityÂ
Certain factors will reduce the numbers to bring it back to carrying capacity
Examples- predation, Â competition, disease, etc
Density-independent factorsÂ
Factors that limit population size regardless of the densityÂ
Affects all populations in a similar wayÂ
Examples- the destruction of habitat, forest fires, droughts, etc
Top downregulationÂ
Top-down limiting factorsÂ
Interactions between top predators and their prey influence population sizes at lower trophic levelsÂ
Increase in top predators
Population decreases in lower levels
Decrease in top predators
The population varies in lower levelsÂ
Bottom-up regulationsÂ
Bottom-up limiting factorsÂ
Limits the availability of resources to lower trophic levels (producers)
Lack of resources at the bottom of the food chain decreases population in all the higher trophic levelsÂ
Population growthÂ
Exponential growthÂ
No limiting factorsÂ
J shaped graph
Logistic growth
Limiting factors are in placeÂ
S-shaped graphÂ
Carrying capacityÂ
Limiting factors determine the carrying capacity for a populationÂ
DefinitionÂ
The maximum number of organisms an environment can support
ExponentialÂ
When resources are readily available population grow rapidlyÂ
Once resources become limitedÂ
The growth rate slows down and reaches a maximum populations size for the environmentÂ
Northern fur seal
In the 1800s, the fur trade led to a drastic reduction in the northern fur seal population. Â
This decline prompted the first international treaty to conserve wildlife
The fur seal population underwent exponential growth following protection
but eventually levelled out at the ecosystemâs carrying capacity
EquilibriumÂ
When the population is maintained at its carrying capacityÂ
The population size is at equilibrium (balance) - logistic growthÂ
Predator-prey relationshipsÂ
Predation
is a biological interaction where one organism, the predator, kills and eats another organism, its prey
Because the predator relies on the prey as a food source, their population levels are dependent on each other
If the prey population drops, predator numbers will decrease due to competition
If the prey population rises, predator numbers will increase due to an over-abundance of a food source
Arctic fox VS snowshoe hareÂ
Species at riskÂ
Species at riskÂ
BiodiversityÂ
The variety of life on earthÂ
The greatest threat to biodiversity species becoming extinct
Extinct speciesÂ
is one that has died outÂ
No longer exists anywhere on earthÂ
Extinction can result fromÂ
Natural disastersÂ
OverhuntingÂ
Habitat loss
Climate changesÂ
Poor reproductivityÂ
Sea minkÂ
Lived around rocky coasts of New EnglandÂ
Also southernmost Maritime ProvincesÂ
Until hunted to extinction in the late 19th or 20th centuryÂ
Risk categoriesÂ
Committee on the status of endangered wildlife in Canada (COSEWIC)
Monitors the status of species Â
Uses data on extinction species to separate species at risk into four categories
ExtirpatedÂ
EndangeredÂ
ThreatenedÂ
Special concernÂ
ExtirpatedÂ
Species that no longer exists in a specific area but does appear elsewhere
Example
Paddlefish extirpated in CanadaÂ
Grizzly bears extirpated in the prairie provincesÂ
EndangeredÂ
Species in immediate danger of becoming extirpated or extinctÂ
 Example
Caribou
North Atlantic right whaleÂ
ThreatenedÂ
Species likely to become endangered if no action is takenÂ
ExamplesÂ
Barn owl
Eastern hognose snakeÂ
Special concernÂ
Species that may become threatened or endangered because of various factorsÂ
ExamplesÂ
Polar bearÂ
Great blue heronÂ
Invasive speciesÂ
The intro to non-native species to ecosystems by humans is a major cause of species lossÂ
Most native species die out because they canât tolerate an entirely new environmentÂ
Some species survive because there are few predators or diseases to limit their growthÂ
An invasive speciesÂ
Is non-native species that have a negative impact on the natural environmentÂ
Can be accidentally or purposefully introducedÂ
Competes with native species for resourcesÂ
NicheÂ
a comfortable or suitable position in life or employmentÂ
Ecology - Grade 9 Biology
Ecology - Grade 9 Biology
Intro to Ecology
Terms:Â
An ecosystem- is a geographic area where plants, animals and other organisms, weather and landscapes work together to form a bubble of life.Â
Biotic factors: include plants, animals and other organisms.Â
Tide pools- contain seaweed, a kind of algae that uses photosynthesis to create food.
Also, depending on the changing level of the ocean water
Biomes- are a large section of land, sea or atmosphere
Forests, ponds, reefs, tundra
Canopies- ecosystems at the top of the rainforest
Tall, thin trees such as fig grow in search of sunlightÂ
Epiphytes- other plants in the canopy ecosystem
Understory- ecosystem under the canopy ecosystem
Delicate coral reef- an ecosystem in the south pacific at risk due to rising ocean temps. And decrease sanityÂ
InterdependenceÂ
Organisms and their environment are interdependentÂ
Every organism relies on other organisms to surviveÂ
Everything depends on something elseÂ
Levels of organization
Study of ecology ranges from the study of an individual organism to the study of the entire plant as the followingÂ
Individual
Population
Community
Ecosystem
Biome
Biosphere
Species
A group of individuals similar to one another that can breed and create fertile offspring
Population
Organisms of one species that interbreed and live together within a defined areaÂ
Examples
Herd of sheep
Flock of geeseÂ
Colony of ants
Culture of bacteriaÂ
Sleuth of BearsÂ
Brood of chickensÂ
Pack of dogs
Communities
Groups of populations comprised many species that live together in a defined area
EcosystemÂ
Combination of the communities and the physical (nonliving) environmentÂ
Is all living and nonliving factors in a particular placeÂ
Can be large and small
Rotting log
Koi pond
Lake
Clump of dirt
Field
Old maple tree
Bog marsh
BiomeÂ
A large area that has a particular climateÂ
Particular species of plants and animals that live thereÂ
TundraÂ
Rainforest
Desert
A large group of many ecosystemsÂ
BiodiversityÂ
Variety of organismsÂ
Organisms genetic differencesÂ
Ecosystems in which they occurÂ
Ecological diversityÂ
Different ecosystems in a regionÂ
Species diversityÂ
Different species within certain ecosystemsÂ
Tropical rainforests have the highest biodiversity of all biomesÂ
Factors that affect ecosystemsÂ
Abiotic
Nonliving factorsÂ
Soil
Pollutants
Natural disasters
Climate
Biotic factors
Living factorsÂ
plants and animals
Biotic and abiotic both determine the survival of growth of individual organisms and ultimately the ecosystemsÂ
HabitatÂ
Where particular populations liveÂ
Include biotic and abiotic factorsÂ
How do ecosystems form?Â
Constantly changingÂ
SuccessionÂ
Progression of species of replacement over timeÂ
Ecosystems evolvingÂ
Typically slowÂ
Natural disasters or human disturbances can make sudden changesÂ
Primary successionÂ
Occurs when no soil previously existed is called thisÂ
The first species to populate the are called pioneer speciesÂ
Secondary successionÂ
Occurs in areas where soil exitsÂ
But has been damaged or disturbedÂ
Forest fire - exampleÂ
Nutrient cyclesÂ
Biogeochemical cyclesÂ
The matter is neither created nor destroyed
Can be transformed and passed on
How carbon, nitrogen and phosphorus pass from the physical environment to living organismsÂ
About themÂ
Bio-life Â
Geo-earthÂ
Chemical-elements and moleculesÂ
3 biogeochemical essential cyclesÂ
Water cycle
Carbon cycle
Nitrogen cycleÂ
Materials to recycle they have to changes/transform statesÂ
Death and decay contribute to the cycles
Animals and plants die
Bacteria other decomposers break them down in raw elementsÂ
Can be absorbed by plants and passed on to animalsÂ
Water cycleÂ
All living things need water to survive
Moves betweenÂ
OceanÂ
Atmosphere
Land
By cycling from water vapour to liquid water
EvaporationÂ
Liquid water returns to the atmosphere (vaporizers)
TranspirationÂ
Evaporation of water from plantsÂ
Both occur during the daytime when the sun heats up the atmosphere
   CondensationÂ
Atmosphere cools
Water vapour in the air condenses to form cloudsÂ
   PrecipitationÂ
Water droplets that form cloudsÂ
Become large enoughÂ
Droplets fall to the earthÂ
Informs ofÂ
RainÂ
Sleet
Snow
   PercolationÂ
When water returns to earth some is absorbed by plants through their rootsÂ
Other seeps into the soil to become groundwater
   Runoff
Surface water found on landÂ
That eventually carries back to a lake or oceanÂ
Water cycle diagramÂ
Carbon cycleÂ
CarbonÂ
Is an essential element for all living thingsÂ
Is found inÂ
Living tissuesÂ
Rocks
Atmosphere
Ocean
Less than 1 % is found on earth is in the carbon cycleÂ
Carbon dioxideÂ
Which is in the air is or dissolved in water is used by photosynthesizingÂ
PlantsÂ
AlgaeÂ
BacteriaÂ
 As raw materials to build organic molecules such as glucoseÂ
Ways (3) carbon can return to air or waterÂ
RespirationÂ
All living organisms undergo cellular respiration
Use oxygen to break down foodÂ
CO2 is a byproduct of the reaction (exhaled)
ErosionÂ
Marine organisms use it to make sheetsÂ
calcium carbonate
When they die the calcium carbonate breaks downÂ
CO forms and returns to the atmosphereÂ
CombustionÂ
When carbon returns to the atmosphere through combustion or burning fossil fuels
Carbon is locked beneath the earthÂ
Dead organisms sediment may gradually transform by heat
And pressure into fossil fuelsÂ
This process of fossil fuels releases CO2Â
Creates greenhouse gases
Nitrogen cycleÂ
Makes up 78% of the atmosphereÂ
Most organisms are unable to use it in this form
Bacteria in the soil is very importantÂ
Can use atmospheric nitrogen
Fix into compounds usable by other living thingsÂ
Organisms need nitrogen to build proteins and nucleic acids
Nitrogen fixationÂ
Bacteria combine nitrogen from the atmosphere with hydrogenÂ
To make ammonia (NH3) in the soilÂ
AmmonificationÂ
Production of ammonia by bacteria during the decay of organic matter
NitrificationÂ
Production of nitrates and nitrites from ammonia (NO3)
Bacteria are responsible for nitrificationÂ
Plants can use nitrites and nitrates to make proteinsÂ
AssimilationÂ
Absorption of nitrogen into organic compounds by plantsÂ
Absorbed through rootsÂ
DenitrificationÂ
Conversion of nitrate to nitrogen gasÂ
Which is released back into the atmosphere
Phosphorus cycleÂ
Is necessary to build DNA moleculesÂ
Also RNA
Not very common in the biosphere and does not enter the atmosphereÂ
Locked into the land or waterÂ
Is found in rocks and minerals in the soilÂ
Rock gradually wear down phosphorus is released into soil or waterÂ
When organisms dieÂ
Decomposers in the soil or water break them down into raw elementsÂ
Including phosphorus which can then be reusedÂ
When plants absorb phosphate from soilÂ
Can be passed along from plants/producers to other trophic levels
Nutrient limitationÂ
The amount that is available directly affects the primary productivity of an ecosystem
Primary productivityÂ
The rate at which producers produce energyÂ
Limited nutrientÂ
Sometimes ecosystems are limited by a single nutrient that is very scarce or cycles slowlyÂ
FertilizersÂ
Are so popularÂ
They contain 3 important nutrientsÂ
NitrogenÂ
PhosphorusÂ
PotassiumÂ
By using this farmers can ensure that there are enough nutrients
Their corps grow to their fullest potential
Earthâs sphereÂ
Any time matter can occupy one of the four spheres that make up the earth
Lithosphere - solid earthÂ
Atmosphere - gases (the air)
Hydrosphere - all waterÂ
Biosphere - all lifeÂ
BiosphereÂ
The lithosphere, hydrosphere, atmosphere are abiotic spheresÂ
Are found on other planets including earthÂ
Earth has fourth called the biosphere
No other planet in the solar system is known to have thisÂ
The biosphere is the living surface of the earthÂ
Is not separate from abiotic spheresÂ
Many life forms are foundÂ
Underground
WaterÂ
AtmosphereÂ
Energy transfer in the biosphere
All living things in here needÂ
SpaceÂ
WaterÂ
NutrientsÂ
To surviveÂ
Nutrients are stored as energyÂ
Energy is continuously cycled by mean of the food chainÂ
A food chain shows how each living thing gets foodÂ
How energy is transferred from one organism to anotherÂ
A diagram to show what it looks like
Food chains vs food webs
AÂ food chain is a linear flow of energy through an ecosystem
A food web shows multiple food chains interconnected in an ecosystemÂ
Multiple energy pathsÂ
Food chains and food webs represent the transfer of energy in a communityÂ
Trophic levelsÂ
In ecology, this level is a position that an organism occupies in a food chainÂ
Energy moves through food webs from one trophic level to the nextÂ
First Trophic Level: Â ProducersÂ
organisms that make their own food through photosynthesis (plant, algae, cyanobacteria)
Second Trophic Level: Primary Consumers
animals cannot make their own food â they eat producers
called herbivores (plant-eaters)
Third Trophic Level: Secondary ConsumersÂ
animals that eat primary consumers
called carnivores (meat-eaters) and omnivores (eat both animals and plants)
Fourth Trophic Level: Tertiary ConsumersÂ
animals at the top level of the food chain
called top carnivores but can be omnivores as well
The end of the food chainÂ
Decomposers
Organisms that break down dead plants and animals
Puts nutrients back into the soil â energy for producers
Examples: Â bacteria, fungi (mushrooms)
Detritivores
a type of decomposer
decomposers like bacteria and fungi don't eat their food, they break it down.
detritivores eat large amounts of decaying material and excrete nutrients.
Examples: millipedes, dung beetles, earthworms, slugs, snails
Grassland food web
Toxins in food chainsÂ
Each time an organism eats another organism, it gains that organism's energy and nutrients.  Unfortunately, it also gains any toxins that might be stored in that organism's cells.
BioaccumulationÂ
the increase in the concentration of a toxin, such as a pesticide, in an individual organism.
Biomagnification- the increase in the concentration of a toxin in a food chain.Â
toxins accumulate in living things at the top of the food chain when they eat infected organisms lower in the food chain.
Ecological pyramidsÂ
The sun and ecosystemsÂ
The fuel for an ecosystem is energy from the sun.
Light energy is used by green plants in the process of photosynthesis to make chemical energy.
Chemical energy is passed up the trophic levels in a food chain.Â
Energy transfer in food chainsÂ
The greatest amount of energy is found at the 1st trophic level. They are the first organisms to use the energy of the sun.
As one organism eats another, some energy is used for survival and some energy is lost as heat to the environment.
Energy Flows In as Sunlight and Out as Heat
Ecological pyramidsÂ
An ecological pyramid helps us visualize the transfer of energy between the trophic levels in a food chain.
There are 3 major types of ecological pyramids:
Pyramids of numbersÂ
A pyramid of numbers shows the relative number of organisms at each stage of a food chain
Pyramids of numbersÂ
A pyramid of numbers can have various shapes. The width of each block should represent the number of organisms.
Pyramid of biomassÂ
A pyramid of biomass shows the total mass of organisms at each stage of a food chain.
Pyramid of energyÂ
This pyramid compares the amount of energy trapped at each stage of the food chain.
Pyramid of energy - 10%
As one organism eats another, 10% of energy passes from one trophic level to the next up the food chain.Â
Since there is less energy moving up the food chain, the population size of organisms at higher trophic levels decreases.
Interactions in ecosystems
Biotic factors in an ecosystem include all living thingsÂ
And the interactions among those living thingsÂ
Interactions define the ecological niche of speciesÂ
What it feeds onÂ
What it eatsÂ
How it behavesÂ
Examples of interactions among living thingsÂ
SymbiosisÂ
Predation
CompetitionÂ
Interactions - symbiosisÂ
Is the interaction between two different organisms living in a close physical relationship
Example - sea anemones and hermit crabsÂ
Sea anemones hitchhike on the back of hermit crabs
Scoring a ride across the seabed and extending their tentacles to est the crabâs leftoversÂ
In return, the anemones fend off hungry octopusesÂ
The other predators use their barbed tentaclesÂ
Types of symbiosisÂ
Mutualism
A relationship where both species benefit from the interaction
Example - sea anemones and hermit crabs,Â
Insects and flowers (pollination)
ParasitismÂ
A relationship where one species benefits(the parasite)
The other is harmed (the host) by the interactionÂ
For example - mosquitos (the parasite) sucks the blood of humans (the host)
CommensalismÂ
A relationship where one species benefits
The other is unaffected (no benefit or harm) by the interaction
Example- egrets (benefits) and the cattle (unaffected)
Remora (benefits) and sharks (unaffected)Â
InteractionsÂ
PredationÂ
Occurs when one organism consumes another organism for foodÂ
The organism eaten is called prey
Organism consuming prey is called predatorÂ
Carnivorous plants - venus fly trapÂ
Affects insects with its flowerlike reddish colour and ripe fruity smellÂ
Insects seek the nectarÂ
It will inevitably touch the highly sensitive hairs on the leaves causing the trap to snap shut at lightning speedÂ
CompetitionÂ
Occurs when two or more organisms complete for the same resource such asÂ
FoodÂ
Water
Mates
Shelter
Example - sarcastic fringeheadÂ
Lives in a small area on the ocean floor where resources for food and space are scarce
When an intruder invades that space,Â
the fringehead attacks fearlessly and aggressively
Photosynthesis and cellular respiration
Energy flow in ecosystems
2 processes that drive energy flow in ecosystems
Photosynthesis
Converts light energy into chemical energy and stores it as food
Cellular respirationÂ
Release stored chemical energy as food
The reverse process of photosynthesis
PhotosynthesisÂ
Occurs in green plants
AlgaeÂ
Some bacteriaÂ
Green plants have an organelle called a chloroplast
It contains chlorophyll which traps light energy from the sunÂ
Carbon dioxide enters in through small openings called stomataÂ
Carbon dioxide, water and light react to make a sugar called glucoseÂ
Some glucose is used to feed that plant and some are stored for later useÂ
During chemical reaction, oxygen is released into the air through stomataÂ
Photosynthesis equationsÂ
Cellular respirationÂ
Occurs in all organismsÂ
Cells break down stored energy (glucose) and release useable forms of energy for body movementÂ
Body heatÂ
ReproductionÂ
Etc.Â
Chemical reactions occur in the mitochondria of cellsÂ
Stored sugar is converted into carbon dioxideÂ
WaterÂ
Chemical energy (ATP)
Carbon dioxide is put back into the atmosphere to be used againÂ
Photosynthesis vs Respiration
Products (ending materials) of one process are the reactants (starting materials) of the otherÂ
Population LimitsÂ
Population and habitatsÂ
PopulationÂ
All individuals of one species that are in a specific area at a certain time
HabitatÂ
In an environment in which a population lives and gets its need metÂ
Food
Shelter
Reproduction
Etc.
What influences population size?
Abiotic factorsÂ
Influence where species can live
Are determined byÂ
Temp.
Soil
Light
SalinityÂ
Etc
Biotic factorsÂ
Influence a species successÂ
Are determined by competition for resources
Food
Water
Mates
IntraspecificÂ
With members of their own speciesÂ
InterspecificÂ
Also with other speciesÂ
Competition in populationsÂ
Is the demand for resourcesÂ
FoodÂ
MatesÂ
WaterÂ
Etc
Intraspecific is competition for mates in different speciesÂ
Interspecific is competition for food in the same speciesÂ
Limiting factorsÂ
Population canât keep growing forever
Once the population is too big for its environmentÂ
The limiting factors regulate its sizeÂ
ExamplesÂ
Food and water supplyÂ
Mates
Predation/competitionÂ
DiseaseÂ
Sunlight
Space (to live and hide)
TemperatureÂ
Natural disastersÂ
Population densityÂ
Is to measure the number of organisms that make p populations in a defined areaÂ
Density-dependent factorsÂ
Population becomes too large for its environmentÂ
High densityÂ
Certain factors will reduce the numbers to bring it back to carrying capacity
Examples- predation, Â competition, disease, etc
Density-independent factorsÂ
Factors that limit population size regardless of the densityÂ
Affects all populations in a similar wayÂ
Examples- the destruction of habitat, forest fires, droughts, etc
Top downregulationÂ
Top-down limiting factorsÂ
Interactions between top predators and their prey influence population sizes at lower trophic levelsÂ
Increase in top predators
Population decreases in lower levels
Decrease in top predators
The population varies in lower levelsÂ
Bottom-up regulationsÂ
Bottom-up limiting factorsÂ
Limits the availability of resources to lower trophic levels (producers)
Lack of resources at the bottom of the food chain decreases population in all the higher trophic levelsÂ
Population growthÂ
Exponential growthÂ
No limiting factorsÂ
J shaped graph
Logistic growth
Limiting factors are in placeÂ
S-shaped graphÂ
Carrying capacityÂ
Limiting factors determine the carrying capacity for a populationÂ
DefinitionÂ
The maximum number of organisms an environment can support
ExponentialÂ
When resources are readily available population grow rapidlyÂ
Once resources become limitedÂ
The growth rate slows down and reaches a maximum populations size for the environmentÂ
Northern fur seal
In the 1800s, the fur trade led to a drastic reduction in the northern fur seal population. Â
This decline prompted the first international treaty to conserve wildlife
The fur seal population underwent exponential growth following protection
but eventually levelled out at the ecosystemâs carrying capacity
EquilibriumÂ
When the population is maintained at its carrying capacityÂ
The population size is at equilibrium (balance) - logistic growthÂ
Predator-prey relationshipsÂ
Predation
is a biological interaction where one organism, the predator, kills and eats another organism, its prey
Because the predator relies on the prey as a food source, their population levels are dependent on each other
If the prey population drops, predator numbers will decrease due to competition
If the prey population rises, predator numbers will increase due to an over-abundance of a food source
Arctic fox VS snowshoe hareÂ
Species at riskÂ
Species at riskÂ
BiodiversityÂ
The variety of life on earthÂ
The greatest threat to biodiversity species becoming extinct
Extinct speciesÂ
is one that has died outÂ
No longer exists anywhere on earthÂ
Extinction can result fromÂ
Natural disastersÂ
OverhuntingÂ
Habitat loss
Climate changesÂ
Poor reproductivityÂ
Sea minkÂ
Lived around rocky coasts of New EnglandÂ
Also southernmost Maritime ProvincesÂ
Until hunted to extinction in the late 19th or 20th centuryÂ
Risk categoriesÂ
Committee on the status of endangered wildlife in Canada (COSEWIC)
Monitors the status of species Â
Uses data on extinction species to separate species at risk into four categories
ExtirpatedÂ
EndangeredÂ
ThreatenedÂ
Special concernÂ
ExtirpatedÂ
Species that no longer exists in a specific area but does appear elsewhere
Example
Paddlefish extirpated in CanadaÂ
Grizzly bears extirpated in the prairie provincesÂ
EndangeredÂ
Species in immediate danger of becoming extirpated or extinctÂ
 Example
Caribou
North Atlantic right whaleÂ
ThreatenedÂ
Species likely to become endangered if no action is takenÂ
ExamplesÂ
Barn owl
Eastern hognose snakeÂ
Special concernÂ
Species that may become threatened or endangered because of various factorsÂ
ExamplesÂ
Polar bearÂ
Great blue heronÂ
Invasive speciesÂ
The intro to non-native species to ecosystems by humans is a major cause of species lossÂ
Most native species die out because they canât tolerate an entirely new environmentÂ
Some species survive because there are few predators or diseases to limit their growthÂ
An invasive speciesÂ
Is non-native species that have a negative impact on the natural environmentÂ
Can be accidentally or purposefully introducedÂ
Competes with native species for resourcesÂ
NicheÂ
a comfortable or suitable position in life or employmentÂ