Introduction to Ecology and Ecosystems Notes

____________ - combines the Greek words oikos, meaning “the place where one lives” with logos meaning “the study of” The study of where we and other organisms live

Habitat - the _______________________________________ an individual needs to survive

Niche - an organism’s _________ within its habitat

Abiotic – ________________ factors in an ecosystem

Biotic – ____________ components of an ecosystem

Levels of Ecological Organization (from smallest to largest)

Organism - a ______________________ of a specific species

Population - all the members of the __________________ living in the same habitat

Community - a collection of ___________________ of many different species in a certain area at a certain point in time

Ecosystem - The relationship between _________________ and __________________ components of a biological community

Biome - many ecosystems in the same ____________ that share the same climate

Biosphere – all of the earth's crust, waters, and atmosphere that supports life

Roles in the EcosystemDifferent organisms all have their own role within an ecosystem. They can be categorized into some common groups.

• _____________: An organism that uses light energy to produce sugar and other organic compounds through the process of photosynthesis is called a producer.

• _____________: Organisms that rely directly or indirectly on producers are called consumers.

• All animals are consumers!

3 Categories of Consumers: primary, secondary, and tertiary.

• Primary Consumer (herbivore): an organism that eats ___________________.

• Example:

• Secondary consumer: an organism that eats _____________________.

• Example:

• Tertiary consumer: an organism that eats _______________________.

• Example:

Other Terms:

• A _______________ is an organism that eats other animals.

• A ______________ is an organism that eats both plants and animals.

• __________ are good examples of omnivores

• They eat fish and other small animals, as well as berries

• Can you think of another familiar omnivore?

• __________________

• A _______________ is an animal that feeds off dead or decaying animals but does not kill them.

• A _______________ is an organism that breaks down complex organic molecules into simpler molecules. This returns nutrients to the soil.

Energy Flow in the Biosphere - Notes Autotrophs – organisms that can make their _____________ from basic nutrients and sunlight or some other non-living source. Also called ________________.- Auto means self, and “troph” comes from Greek word meaning “feeder”. Therefore autotroph means “_____________”

Heterotrophs – consumers at any level that __________________ their own food, and therefore must obtain their food and energy from autotrophs or other heterotrophs. Includes consumers, scavengers, and decomposers. (Hetero means different or other – so heterotroph = “____________________”)

___________ Level – a category of living things defined by how it gains energy.-The trophic levels are numbered based on the number of steps they are away from the _________

___________ Trophic Level: Producers (autotrophs)Second ____________ Level: Primary Consumers (eat producers)Third Trophic Level: ________________ Consumers (eat primary consumers)Fourth Trophic Level: Tertiary Consumers (eat secondary consumers)

Example Food Chain Sun grass mouse snake falconRole in Food Chain Producer Primary

ConsumerTertiary

ConsumerTrophic LevelSteps from the Sun 1 2 3 4

Try it!

Label the organisms with the

terms below.

herbivore producer

carnivoredecomposer

autotroph

primary consumersecondary consumer

heterotroph first trophic levelsecond trophic level third trophic level

Energy and Food Chains- food chains are a way of showing a one way, step-by-step, sequence of who eats whom in an ecosystem.-we use____________ to show energy flow – that’s why the arrow always points to the ________ trophic level

Sun ______ producer _______ primary consumer _______ secondary consumer _______ tertiary consumer

Food Webs

- food chains are unlikely to include all the organisms in a natural ecosystem- each individual organism in an ecosystem is involved in ________ food chains- the chains all interlock to form a feeding relationship called a ________________

The Role of Producers

Food webs always begin with ______________ –photosynthetic organisms at the first trophic level (ie. plants) - _________________ ultimately provides the energy required by the entire ecosystem.

Equation for Photosynthesis:

_________________ + water + ___________ ____________ + oxygen

Using the Energy:

All organisms (including plants) undergo _____________________________ in order to use the energy in their food.

Equation for Cellular Respiration:

___________ + oxygen _______________ + water + ___________

Biodiversity

Biodiversity – the number of species in an ecosystem, and the _____________ within those species

Ecosystems with the greatest ________________ are the most stable.

- they have such complex and well-developed food webs that reduced numbers or even the complete removal of one type of organism may only have a _____________

Where abiotic factors limit the number of organisms, the web looks more like a food chain.- the relationship between organisms is more direct- the loss of one member would have a _______________ effect on the remaining organisms

Limits on Energy Transfer – Notes Energy Transfer between Trophic Levels

Every time energy is transferred between the components of an ecosystem, the amount of energy available to the next trophic level is ____________.

______________ of the energy captured in photosynthesis is available to the animal that eats the plant because the ___________ used most of that energy to carry out its life processes

Primary consumers do not ___________ all of a plant meal, some is lost in the feces. Of the remaining energy, some is lost __________________________ from the chemical transformations of digestion and through cellular respiration and the animal’s activity.

_________ of the energy plants receive is stored, and therefore is passed on to the primary consumers

_________ of the energy that primary consumers receive is stored and passed on to Secondary consumers

-the farther up the food chain, the less energy that is available-this usually limits the number of trophic levels in a food chain to about 5

Thermodynamics is the study of energy transformations

First Law of Thermodynamics: although energy can be changed from one _________ to another, it cannot be ___________________________.

Second Law of Thermodynamics: during any energy transformation, some of the energy is converted into an ___________________, (usually thermal energy) that cannot be passed on.

Human Use of Energy in Ecosystems

- humans are dependent on the ________________ through ecosystems just like all other living things.- we are part of many food chains at ________________________, dependent on what we are eating. Think about it: Are we more efficient when we eat like Herbivores or Omnivores? Why?

- we also used the energy for fuel for heat (example: burning wood)- humans have permanently ______________ many ecosystems in order to grow and hunt food.

Scientific Models of Energy in the Biosphere- scientists often construct ______________ to help them understand how living things work.- models are theoretical descriptions or ___________________ that help us visualize something that has not been directly observed.- they provide a pathway for making predictions.

Ecological pyramids – graphs used to represent ________________ flow in food chains and food webs or the ________________ of organisms in a food chain.- allow ecologists to visualize the relationships in an ecosystem and compare them.- NOTE: graphs of natural ecosystems may or may not look like a pyramid!

Pyramid of Numbers

A Pyramid of Numbers can be drawn by _____________ the number of organisms at each trophic level in an ecosystem. As you move up the trophic levels, the number of organisms decrease.

-That is why there is a ratio of about __________ grasshoppers to every _____ falcons.

-However something strange can happen with the number of producers – _____________ producer can support many smaller consumers

Pyramid of Biomass

Biomass is the total ______________ of all the living material in an ecosystem.

Since organisms store ___________ as organic molecules, biomass is a measure of stored

energy,

as well as the size of organisms at each level.

Pyramid of Energy

A Pyramid of Energy is created by measuring and graphing the amount of ______________________

at each trophic level.

It allows a ______________ understanding of the relationships and energy flow at each trophic level.

Large mass and the energy demands of hunting

limits the number of consumers that can be

supported at the top of the pyramid.

Water Cycle NotesThe Zones of the BiosphereThe biosphere is made up of three distinct zones:

1)________________ (land)2) _______________ (water)3) _______________ (air)

The HydrosphereEach year as glaciers melt, they release water from melting snow to form _____________streams, rivers and lakes. But snow, ice, water in rivers and lakes, and water vapour in the atmosphere make up only a _______________________ of all the water on Earth.

Most of the water is found in oceans where the water is ___________ so we can’t drink it.

All of the Earth’s water, both fresh and salt, forms what is called the ___________________

Water Distribution in the HydrosphereOnly a very small portion of the hydrosphere consists of fresh water. Most of this fresh water is ___________ in glaciers and in the ice caps around the North and South Poles.

In fact, if all the water in the world were represented by one litre of water, then all the fresh, unfrozen water in the atmosphere, lakes and rivers would be _______________________________!

With its vast freshwater supplies, Canada is one of the ____________________ countries in the world. Our population is just 0.5% of the world total, yet we have almost 10% of the world’s supply of fresh water.

The Water CycleBecause so much of the Earth’s surface is covered in water, the weather systems depend greatly on water in its three __________________: solid, liquid and gas.

Energy, mostly from the sun, causes water to _____________ (changing from liquid to gas), or ice to __________________ (changing directly from solid to gas) to become water vapour in the air. ____________________also occurs, which is evaporation of water from the leaves of plants.

As the gaseous water rises and the pressure and temperature of the atmosphere decrease, the water vapour ___________________ (changes from gas to liquid), into fog, mist and clouds. If the temperature is low enough, water vapour may form ice crystals by _______________________ (changing directly from gas to solid). _______________________ of some kind (rain, hail or snow) - then falls to the ground.

Once water is on the ground it can either run along the surface of the ground as _________________ to ________________ in streams, rivers, lakes, and the oceans (_________________); or it can seep down through the soil into underground reservoirs of

water called ______________ to become ____________________.

Humans and the Water CycleFresh water is vital for human ______________. Throughout human history, people have made their settlements near sources of __________ water.

Since a large portion of the population still lives __________________, both near fresh water and on coastlines where fishing provided food, human populations are still very tied to water.

___________________ on and near large bodies of water greatly affect large numbers of people, and changes in the amount of water available (__________________________) have a major impact on these populations. The effects will become greater as the population increases, and as climate change becomes more ______________.

The Carbon Cycle - NotesThe Carbon Cycle - the cycle of matter in which carbon atoms move from an ____________ form to an organic form and then back again

Living organisms get carbon from their________ (other organisms), and return carbon dioxide to the atmosphere by cellular respiration.

This creates a _______ because photosynthesis and cellular respiration are complementary processes

Photosynthesis: CO2 + H2O + energy C6H12O6 + O2

Cellular Respiration:

C6H12O6 + O2 CO2 + H2O + energy

Where do we find Carbon?____________________ can be found in the atmosphere, the ocean, and Earth’s crust____________________ is found in the bodies of living things and in other carbon sinks_______________ – a natural or artificial _______________ that accumulates and stores carbon-containing compounds for a particular length of time

Natural sinks include: _____________, living organisms, peat bogs & permafrostArtificial sinks include: _____________, carbon capture and storage projects

Human Impact on the Carbon CycleWe release carbon from organic reservoirs (carbon sinks) by burning ___________________We also increase the amount of carbon dioxide in the atmosphere by clearing ___________________

1. Greenhouse Effect – atmospheric gases that surround the Earth (such as ____________________ and _______________) trap the heat from the sun and warm the Earth’s surface.2. Global Warming – the burning of wood and ________________ have caused carbon dioxide levels to triple over the past 40 years. In that time global temperatures have increased by 1 degree Celcius.- Some Problems Include:

- In the Arctic _________________ will thaw, causing roads & buildings to collapse (releases more carbon)-_____________ and glaciers will melt, rivers will overflow, and ocean levels will _______ causing cities to flood or be submerged, and some island nations to disappear completely. This will create many _______________________.- Changing sea levels will also change ____________________________, leading to surprising changes in climates around the world (cooling in Europe due to the Gulf Stream disappearing)- Changing climates will drastically change _________________ – plants and animals will need to shift their ___________________ to new areas to survive.

- Many ______________________________will become more frequent, severe, and unpredictable.

Nitrogen Cycle NotesNitrogen Cycle – the cycle of matter in which nitrogen atoms move from ____________________ in the atmosphere, to inorganic forms in the _________, to organic forms in ___________________, and then back to inorganic forms in the soil and nitrogen gas in the atmosphere.

- Nitrogen is required for cells to make ____________ and _______- Although nitrogen gas in abundant in the ___________________ (79%), in order to be useful to plants, nitrogen must be in the form of a ______________ ion (NO3-).

Nitrogen fixation – two processes in which atmospheric or dissolved nitrogen is _______________ into ______________ ions.

- lightning- nitrogen-fixing bacteria, found in _______________

______________________ – the process in which nitrates are converted to nitrites and then to nitrogen gas which is released back into the atmosphere.

- carried out by bacteria that do not need ____________ (anaerobic)

- speeds up when soil is acidic or

____________________

As a result, gardeners often ____________ their lawns to increase oxygen levels and allow nitrates to remain in the soil.

Plants require nitrates to make chlorophyll. If nitrates are lacking, a plant’s leaves will not have a rich ____________ colour

Human Impacts on and Uses of the Nitrogen CycleHumans depend on the Nitrogen cycle just like all other organisms.

Since the very first use of agriculture, farmers have found that crops grown in the same plot of land every year start to suffer from nitrogen deficiency. _________

and _______________ in particular use up nitrogen (and phosphorus) very rapidly. One way to address this problem is to use crop rotation.

_____________________ – The practice of growing a series of different ___________________ in the same area in sequential seasons in order to replenish soil nutrients such as nitrogen.

-Crop rotation has been used since _______________ by early farmers in the Fertile Crescent, when they alternated planting legumes (with their nitrogen-fixing bacteria) and their other crops.

-The Romans also used goat, sheep, cattle, and other _________ to use as a natural fertilizer

____________________________ – Henry Cavendish found a way to synthetically fix atmospheric nitrogen into nitric acid in 1784, and the more modern Haber process to make ammonia was developed in the 1910s. Since then we have been able to create our own sources of nitrogen for plants, without the need for the bacteria found in legumes.

Use of some type of fertilizer (natural or synthetic) can increase yields by ___________

Synthetic fertilizers have become very important and are often over-used to try to raise crop yields even higher

The numbers on a bag of fertilizer tell you the Nitrogen, Phosphorus and Potassium content

Over use of FertilizersWhen fertilizers (especially synthetic ones) are over used, there are several problems that can occur:

_______________________ – when fertilizers wash off into streams or leach into ground water they can cause algal blooms which lead to dead zones in streams, lakes, and even the ocean

Fertilizer ________________ – many farmers are completely dependent on expensive fertilizers, and the soil becomes stripped of important trace nutrients etc., which requires more fertilizers

________________________ – regular use of fertilizers can lead to the soil becoming too acidic for plants to grow properly. In this case a base such as ground limestone, must be added.

Fertilizer ________ – plants can receive too much of certain nutrients, leading to damage to the plants.

High ____________Consumption – it takes a huge amount of energy to produce fertilizers synthetically.

For all of these reasons, there is a resurgence of crop rotation and the use of _________________ (non-synthetic) fertilizers.

Ecosystem Services & Biodiversity (Crash Course Ecology #10)

Healthy ecosystems provide humans with a range of ___________________ which benefit our lives, and would be extremely expensive to replace. The main types of ecosystem services can be classified as:

_____________Services – create and replenish the foundation of the earth’s biological systems. Such as recycling necessary compounds (biogeochemical cycles), forming new soils, producing oxygen for us to breathe_________________ Services – giving us the raw materials we need to live, such as food, water, fibre, fuel________________ Services – moderating many of the earth’s systems that can be dangerous if they “get out of whack”. Decomposing dead things, filtering the air and water, regulating the climate._______________ Services – ecosystems are just kind of awesome. Ecosystems give us places to play, scenes to inspire us, and things to discover and learn about.

Economists have calculated that if we had to do all the things that ecosystems do for us, it would cost _____________________ dollars per year…the output of the global economy is only ______ Trillion dollars per year!

*Ecosystems can only provide these services if they are intact,

specifically if their ______________ is intact.*BiodiversityBiodiversity makes ecosystems more resilient to change. Ecosystems with high biodiversity are way more resilient to ____________________ than those with low biodiversity. In high-biodiversity system if you take one species out of the mix, it’s less likely that the ecosystem will ____________. In a hectare of Amazonian rainforest there are more species of plants and animal than in all of Europe! If a species of insect goes extinct it is less likely that the house of cards will fall than in a low biodiversity ecosystem like the Sonoran desert where there are very few organisms, so the disappearance of one species could affect the _____________ ecosystem.

The best way to understand our impact on the environment is through how we affect ____________________.

6 Main Human Impacts on the Environment-__________________ – Removing what makes a forest a forest (trees!). Estimated that we are clear cutting about 8000 hectares of trees a day to graze cattle and use the wood. High biodiversity system becomes a low biodiversity system. Also leads to other problems such as erosion.-__________________ – overgrazing and over irrigation lead to productive ecosystems turning into dessert ecosystems. -______________________ – More CO2 (the Principle greenhouse gas) in the atmosphere = warmer climate. Deforestation means fewer plants to use up CO2, and at the same time we are releasing greenhouse gases into the atmosphere at high rates by burning fossil fuels. Changes ecosystems and habitats which harms species – and happening at a rate that is difficult for species to react to by adapting or moving; so this also reduces biodiversity.-____________________ – Introducing non-native species to an ecosystem either intentionally or unintentionally. These invasive species outcompete (or just eat) native species to the point that it “rocks the world of an entire ecosystem”-____________________ – Most direct impact on biodiversity is overharvesting certain species. We overfish the oceans to mean demand for food sources such as tuna, and we exterminate predators such as wolves to protect livestock. This reduces biodiversity, so those ecosystems become more vulnerable to other disturbances.A whole separate set of effects on the Biosphere: -________________ – putting the wrong amounts of certain stuff in the wrong place at the wrong time.

Pollution Video Notes: (Practice your note-taking skills during this video – aim for 5-8 notes on key points)

Population Dynamics – NotesThe total number of a certain species found in an area at a particular time is called a population. ________________________________ is the study of how populations change over time.

Four Population FactorsThe number of individuals in a population is affected by four major factors:

_____________ – number of births _____________ – number of deaths _________________ – individuals moving in from outside _________________ – individuals moving out of the population

Open and Closed Populations ___________ Populations are affected by all of the four factors

o Most natural populations are open populations ______________ Populations are populations where no one leaves or moves

in. Closed populations are only affected by the number of _________ and ____________.

o An isolated island populationo A population in a ________ or other preserveo Global ______________ population

Population HistogramsPopulation __________________ are used to study populations of long-lived organisms such as humans. They usually provide a profile of age groups by sex. This allows us to study the age structure of the population at a particular moment in time.

Limits on Populations• There are limits on all populations. The first type of limits are those limits

imposed by the species itself• ________________________: The maximum number of offspring an organism can

produce with unlimited resources in their habitat.

Four Factors of Biotic Potential1) ______________________: maximum number of offspring per birth–Whooping cranes lay two eggs per year, but only one survives–Rabbits can have litters of up to 11 kits

2) ________________________: Number of offspring that survive until they are able to reproduce

–Sea turtles lay dozens of eggs at a time, but only a few offspring reach the sea, and fewer still reach maturity

3) _________________: the number of times that a species reproduces each year–Elk mate only once per year, in the fall–Rabbits can breed up to 8 times per year

4) _______________________________: the age of sexual maturity and the number of years the individual can reproduce

–African elephants reach sexual maturity at 15 years of age, and may reproduce until age 90

Limiting Factors on Populations ___________Factors: non-living factors

o light, temperature, chemical environment (nutrient levels, toxin levels), water availability, weather

____________ Factors: living factorso food, predators, diseases, parasites, competition for resources

Density ___________________ Factors: affect members of a population regardless of population density

o Fire, flood, drought, other natural disasters, climate change, destruction of habitat

Density ______________ Factors: affect a population because of the density of the population

o Food supply, water quality, sunlight, disease, territory, predation, invasive species

________________________: the maximum number of individuals of a species that can be supported indefinitely by an ecosystem. The carrying capacity is determined by all of the limiting factors above.

Types of Growth ____________________ (S-curve): When a population increases quickly and

then the growth rate slows and the population stabilizes around the carrying capacity of the environment.

o An S-curve shows a population that is limited by factors such as disease, space, competition for resources, and famine.

o Theoretically the “S-curve” is smooth, but in reality the population tends to fluctuate somewhat around the carrying capacity.

_______________________ (J-curve): When a population increases at a constant rate, with no slowing or levelling off.

- The __________ population of Earth has been showing exponential growth throughout the modern age

- Can this kind of growth continue forever? – _____ Populations will always ________ when they run out of

resources

Sustainability & Sustainable Development - Notes

“We do not inherit the earth from our ancestors; we borrow it from our children”

– Moses Henry Cass

Sustainability (2 Definitions)- Improving the quality of human life while living within the _____________________ of supporting ecosystems- The capacity of our human society to continue ______________ within the natural

cycles of the earth.

Seven Generations Concept: an ecological concept that urges the current generation of humans to live sustainably and work for the benefit of the seventh generation (about ______ years) into the future.

-this idea comes from Iroquois teachings: Chief Oren Lyons of the Onondaga Nation has written that it is a responsibility of chiefs to “make every decision that we make relate to the welfare and well-being of the ______________ generation to come”

4 Basic Care Instructions for our Planet – developed by scientists in ________________ Reduce our dependence on ___________________ and heavy metals Reduce our dependence on __________________________ that persist in nature Reduce our ____________________ of nature Ensure we are not stopping people globally from meeting their

_________________

Sustainable Development: Development that meets the ____________________________ without compromising the ability of _________________________________ to meet their own needs

Think about it:1. Look back over all of the notes from this unit. What are some ways that humans

have been developing unsustainably? (Look at the 4 “care instructions”) Try to come up with at least 4 examples.

2. Suggest some actions that we could take to act more sustainably. Try to think of one for each category:

a. As individuals (what can YOU do?)

b. As a city (Regina)

c. As a Province (Saskatchewan)

d. As a country (Canada)