EOC Review Reporting Category 5

Interdependence within Environmental Systems

The student will demonstrate an understanding of the interdependence and

interactions that occur within an environmental system and their

significance

Langham Creek High School 2012-2013

Ecosystems • An ecosystem consists of all living and nonliving

things within a certain location.

• Ecosystems are made up of the interactions that occur among the living organisms of a particular place, and between those organisms and their surroundings.

• The living parts of an ecosystem are called biotic factors; ex. trees and animals

• The nonliving parts of an ecosystem are called abiotic factors; ex. soil, water, temperature, and light

Ecosystems • A population is a group of individuals that belong to the

same species and live in the same area.

• All of the populations in an area make up a community.

• A biome is a large area characterized by its climate and the organisms that live there.

• Due to limited resources, each ecosystem has a maximum number of individuals that it can support, called its carrying capacity.

Ecosystems • Talk to your neighbor…

– What is happening at b?

– What is happening at c?

– What is happening at d?

• What is the relationship between an individual and a community?

• How is an ecosystem different from a community?

Ecological Succession

11D – Describe how events and processes that occur during ecological succession can change populations and species diversity

Ecological Succession • Succession is a natural process of replacement

of one community by another community in the same location over time.

• A pioneer community is made up of the first living things to move into a new environment.

• Pioneer species are usually small, fast-growing plants. Ex. Lichens and mosses

11D – Describe how events and processes that occur during ecological succession can change populations and species diversity

Ecological Succession • Primary succession is the development of a

community in an area where no living things previously existed.

– Ex. - after volcanic eruptions or retreating glaciers.

• Secondary succession is the replacement of one type of community where an existing community was destroyed or removed.

– Ex. - following a forest fire or deforestation.

11D – Describe how events and processes that occur during ecological succession can change populations and species diversity

Ecological Succession • Talk to your neighbor…

– If a fire destroys a section of forest, what would you expect to see happen over time?

11D – Describe how events and processes that occur during ecological succession can change populations and species diversity

Ecological Relationships

12A – Interpret relationships, including predation, parasitism, commensalism, mutualism, and competition among organisms

Ecological Relationships • All organisms interact with others

and with their environment to meet their basic needs.

• Symbiosis is a relationship in which two different organisms live in a close association with each other.

12A – Interpret relationships, including predation, parasitism, commensalism, mutualism, and competition among organisms

Ecological Relationships • Mutualism is a symbiotic relationship in which

both species are helped.

– Ex. - mutualism exists between you and the bacteria E. coli which provides vitamins for your body, and in return, you provide nutrients and shelter (in your intestines)

12A – Interpret relationships, including predation, parasitism, commensalism, mutualism, and competition among organisms

Ecological Relationships • Commensalism is a symbiotic

relationship where one species is helped and the other species is neither harmed nor helped. – Ex. - Spanish moss grows on the branches of large trees.

The moss is helped because the trees provide a safe place to live with plenty of sunlight, but the larger trees are not harmed or helped.

12A – Interpret relationships, including predation, parasitism, commensalism, mutualism, and competition among organisms

Ecological Relationships • Parasitism is a symbiotic relationship

where a parasite benefits by harming a host. Ex. - A flea is a parasite of dogs.

• Parasites do not usually kill their hosts, because without a host, the parasite would die.

12A – Interpret relationships, including predation, parasitism, commensalism, mutualism, and competition among organisms

Ecological Relationships • Competition and predation are also important

interactions.

– Competition is an interaction between two or more species that use the same resources.

• Ex. – birds and mice compete for food (crickets)

– Predation is when one organism eats another.

• Ex. - hawks kill and eat other animals (like mice). Hawks are predators and mice are prey.

• Predation is an important relationship because it provides the predator with the energy it needs to carry out life functions.

12A – Interpret relationships, including predation, parasitism, commensalism, mutualism, and competition among organisms

Ecological Relationships • Predation also controls the size of predator

and prey populations.

• If the predators over-hunt its prey, the population of prey will decrease.

• Eventually, as the predators run out of food, the predator population will also decrease.

• With fewer predators, the number of prey will be able to increase.

• This causes a cycle of population increases and decreases over time.

12A – Interpret relationships, including predation, parasitism, commensalism, mutualism, and competition among organisms

Ecological Relationships • Talk to your neighbor…

– Use the graph to explain the relationship between the snowshoe hare and the lynx.

– Matching 1. Mistletoe A. Commensal

2. Pollinator B. Mutualistic

3. Barnacle C. Parasite

12A – Interpret relationships, including predation, parasitism, commensalism, mutualism, and competition among organisms

Energy Flow • The interactions that take place among

biotic and abiotic factors lead to transfers of energy and matter.

• Every species has a particular role, or niche, in an ecosystem.

• Autotrophs are organisms that use energy from the sun to produce their own food.

• Autotrophs are also known as producers.

12C – Analyze the flow of matter and energy through trophic levels using various models, including food chains, food webs, and ecological pyramids

Energy Flow

12C – Analyze the flow of matter and energy through trophic levels using various models, including food chains, food webs, and ecological pyramids

Energy Flow • Heterotrophs are organisms that depend on other

organisms for food.

• Heterotrophs are also known as consumers.

• A heterotroph that eats only plants is known as an herbivore.

• Heterotrophs that eat meat are called carnivores.

• Omnivores are heterotrophs that eat both plants and animals.

• Scavengers (detritivores) are heterotrophs that feed on animals that are already dead.

• Decomposers are consumers that break down and absorb nutrients from dead or decaying organisms.

• Many bacteria and most fungi are decomposers. 12C – Analyze the flow of matter and energy through trophic levels using various models, including food chains, food webs, and ecological pyramids

Energy Flow • Food chains and food webs are pictures that

show relationships among organisms.

• Each link in a food chain/ web represents a feeding step or trophic level.

• The arrows in a food chain or food web show the direction of energy flow.

• Arrows point to the organism that receives the energy.

12C – Analyze the flow of matter and energy through trophic levels using various models, including food chains, food webs, and ecological pyramids

Energy Flow • A food chain represents one possible path for the

transfer of energy in an ecosystem.

• A food web shows many possible feeding relationships.

12C – Analyze the flow of matter and energy through trophic levels using various models, including food chains, food webs, and ecological pyramids

Energy Flow • Trophic levels: steps that energy passes through.

• The passage of energy through an ecosystem is accurately represented as a pyramid because the producers contain the most energy.

• Only about 10% of energy passes from one level to the next. At each higher step, some energy is “lost” to the environment as heat.

12C – Analyze the flow of matter and energy through trophic levels using various models, including food chains, food webs, and ecological pyramids

Energy Flow • Talk to your neighbor…

– What percentage of energy is available to a hawk that eats a mouse which ate a cricket that ate a blade of grass?

– Which organisms in an ecosystem have the greatest amount of biomass?

12C – Analyze the flow of matter and energy through trophic levels using various models, including food chains, food webs, and ecological pyramids

Ecological Change

• Ecosystems face change on a regular basis.

• A stable ecosystem can cope with these fluctuations with out much change.

• Severe changes in an environment are likely to upset an ecosystem’s stability.

• If a population cannot overcome environmental changes and continue to reproduce then their numbers will decrease and may become extinct.

12F – Describe how environmental change can impact ecosystem stability

Ecological Change

• Biodiversity refers to the variety of organisms in a given area.

• The more diverse an ecosystem is, the more likely it will be to adjust to changing conditions.

– Ex. - if an ecosystem is disrupted and a species is lost, an ecosystem rich in biodiversity will likely have other species available to fill in for the loss.

12F – Describe how environmental change can impact ecosystem stability

Ecological Change

• Naturally occurring events such as, storms or forest fires, or man made events can cause ecological change.

• Human activities can cause habitat loss and pollution.

• Humans can also cause ecological change by introducing invasive species.

– Invasive species grow uncontrollably and harm the native species.

12F – Describe how environmental change can impact ecosystem stability

Ecological Change

• Talk to your neighbor… – A naturally occurring event would most likely cause

what process to start?

– Why are invasive species destructive to a stable ecosystem?

12F – Describe how environmental change can impact ecosystem stability

Carbon & Nitrogen Cycles • All living things depend on carbon compounds.

• The carbon cycle is a set of processes that moves carbon between Earth’s atmosphere, Earth’s surface, and living things.

12E – Describe the flow of matter through the carbon and nitrogen cycles and explain the consequences of disrupting these cycles

Carbon & Nitrogen Cycles • Disruptions to the carbon cycle

– Increasing levels of carbon dioxide from burning fossil fuels is putting more carbon dioxide in the atmosphere quicker than it can be removed through the carbon cycle.

– Thought to contribute to global warming.

– Also contributes to rising levels of acid in the oceans, called acidification, this negatively effects marine organisms that have a low tolerance for changes in pH.

12E – Describe the flow of matter through the carbon and nitrogen cycles and explain the consequences of disrupting these cycles

Carbon & Nitrogen Cycles • Nitrogen makes up 78% of Earth’s atmosphere.

• In the nitrogen cycle, nitrogen moves between the atmosphere, earth’s surface, and living things.

12E – Describe the flow of matter through the carbon and nitrogen cycles and explain the consequences of disrupting these cycles

Carbon & Nitrogen Cycles • Disruptions to the nitrogen cycle

– Farmers use nitrogen as part of the fertilizer to increase plant growth. Excess fertilizer runs off into bodies of water.

– This upsets the balance of nitrogen in the water and stimulates the growth of aquatic plants and algae. Then the bacteria that feed on the plants as the die and decay consume so much oxygen that fish and other organisms that need oxygen cannot survive.

– Excess nitrogen in the atmosphere can also be a cause of acid rain.

12E – Describe the flow of matter through the carbon and nitrogen cycles and explain the consequences of disrupting these cycles

Carbon & Nitrogen Cycles • Talk to your neighbor…

– Which biomolecules are cycled in the carbon cycle?

– Which biomolecules are cycled in the nitrogen cycle?

12E – Describe the flow of matter through the carbon and nitrogen cycles and explain the consequences of disrupting these cycles

A Little Practice

12E – Describe the flow of matter through the carbon and nitrogen cycles and explain the consequences of disrupting these cycles

A Little Practice

12E – Describe the flow of matter through the carbon and nitrogen cycles and explain the consequences of disrupting these cycles

A Little Practice

12E – Describe the flow of matter through the carbon and nitrogen cycles and explain the consequences of disrupting these cycles

A Little Practice

12E – Describe the flow of matter through the carbon and nitrogen cycles and explain the consequences of disrupting these cycles