Science- Ecosystems (Unit 2)

ecosystems

Ecosystems include all living things and nonliving things
Living things include : plants, animals, and organisms
nonliving things include : weather, sun, soil, climate, rocks, etc.
- Each organism in the ecosystem has its own niche, or role
- Organisms interact with one another in their ecosystem
- Habitats are where animals live
Ecosystems have abiotic and biotic factors
- Abiotic- Nonliving (examples: sunlight, water, soil, oxygen, carbon, rocks)
  - Abiotic factors are needed for biotic organisms to survive
- Biotic- Living (examples: people, plants, animals)
Climate and soil determines what types of producers can grow in each ecosystem

Types of Biomes

Terrestrial: Terre means land, Terrestrial relates to land

Aquatic: Aqua means water, Aquatic relates to water
- There are two types of aquatic ecosystems: Freshwater and saltwater

Freshwater ecosystems: do not have salinity (salt)
- Examples: Lake, Pond, River, Stream, Creek

Saltwater ecosystems: have salinity (salt)
- Examples: Ocean, estuaries, Salt Lakes, salt marshes

Estuaries: mixture of salt and freshwater
- Estuaries are the place where rivers slow down and empty into the ocean
- Also known as a baby nursery because the area is rich in nutrients and producers

Food Chains, Food Webs, and Energy Pyramids

Ecosystems have many types of food chains and food webs
- Food Chain: show the movement of energy between organisms
  - Food chains represent the cycle of life
- Food Webs: show how food chains are interconnected within an ecosystem
If one link in a food chain is destroyed or becomes endangered then the entire ecosystem may fail
Energy flows in the direction that the arrow faces in the diagram

Energy Pyramids: shows us how energy transfers from one organism to the next on the food chain
- The energy we get from food depends on where it sits in the energy pyramid.
- The higher up the pyramid, the less energy it contains because energy filters out as it passes from organism to organism
  - Tertiary consumers (top of the pyramid): eat the secondary consumers
  - Secondary consumers: eat the primary consumers
  - Primary consumers: eat producers (insects, birds, and krill)
  - Producers: (bottom of the pyramid) brings energy from the sun
- Energy flow is shown as a pyramid because the consumers at the top have much less energy available to support them than those closer to the bottom.
  - That is why their numbers are relatively few in most communities
- If one consumer is taken out of the food chain, the others will either increase or decrease over a gradual period of time
  - If a carnivore is removed, the herbivores would increase

Food pyramid

Ecosystem Failure- Ways the environment can be harmed

Humans:
- Humans are the number one cause for ecosystem failures
- over hunting animals or killing for sport
- oil spills in bodies of water
- building and taking away habitats and food sources
- over fertilizing
- adding chemicals to producers to kill insects
- Toxins are what humans put in the ecosystem
Natural disasters:
- Flooding
- Hurricanes
- Tornados
Greenhouse effect and global warming is due to pollution

Producers

Producers: produce their own food through the process of photosynthesis
Photosynthesis: allows plants to create their own food by using light energy from the Sun, carbon dioxide from the air, and water from the soil
- Producers determine what type of consumers live in each ecosystem
- All food chains and food webs begin with producers (plants)
- Ocean producers include: seaweed, seagrass, algae, coral
- Pond producers include: water lilies, lily pads, duckweed, algae, cattails
If there were a drought, or a long period of time without water, the producers would be the first part of the food chain to suffer and then would gradually affect herbivores, carnivores, and omnivores

IMPORTANT:

When producers and consumers are taken out of an ecosystem, animals have to compete for everything a producer provides (shelter, food, habitat and protection)

Consumers

Consumers: consumes or feeds on plants or other animals for energy
Many consumers can live in the same habitat because they eat from different sources

There are four types of consumers

Herbivores: consumers that only eat plants
- Examples: deer, rabbits, cows, goats, elephants, giraffes, pandas
Carnivores: (‘carni’ means flesh) consumers that only eat meat
- Examples: Wolves, mountain lions, hawks, snakes, toads
Omnivores: (‘omni’ means all) consumers that eat both plants and meat
- Examples: humas, ants, chickens, mice, bears

Decomposers

Decomposers: break down dead or decaying organisms and returns nutrients back into the soil
- Worms, mushroom, fungi, bacteria
- Without decomposers eventually everything in the food chain would die out
- Dead plants and animals become nutrients for the soil because of the work of decomposers
Nitrogen Cycle:
- 78% of the atmosphere is nitrogen
- Nitrogen in its gas (gaseous) form is almost entirely unusable to people and animals
- Nitrogen must be “fixed” in order for it to be used by producers.
- Bacteria works to fix nitrogen so that it can be used by plants and animals

Carbon Dioxide and Oxygen are cycled between consumers and producers

Types of decomposers

Scavengers

Scavengers: work as nature’s clean up crew
- Scavengers go to work before decomposers
- Buzzards (or vultures) are considered scavengers
  - They do not kill their own food, but eat roadkill or whatever is left after the predator is finished eating from the prey

Unicellular

Also known as single celled or one celled
These cells CANNOT be seen with your eyes
Must use a microscope to see single celled organisms
Unicellular Organisms are the recyclers of the ecosystem

Multicellular

Also known as complex cells or many cells
These cells CAN be seen with your eyes
Multicellular organisms are in each food chain and food webb

Symbiosis/Predator and prey relationships

Symbiosis is a close relationship between two different kinds of organisms
There are three main types of symbiosis
Mutualism: a relationship in which both organisms benefit (+ +)
- Example: bacteria live in the digestive system of cows and help the cows to break down the plants that they eat and in return the cows provide a place for the bacteria to live and a source of food for the bacteria
Parasitism: a relationship which one organism (the parasite) benefits from the relationship at the expense of the other (+ -)
- Example: Fleas and mosquitoes feed on blood from other organisms
Commensalism: a relationship in which one organism benefits while the other is not affected
- Example: A hermit crab taking up residence in an empty seashell or a spider building a web in a tree

Ecosystem

Vocabulary

|[List 1]|

Abiotic: nonliving parts of an ecosystem
Biotic: living parts of an ecosystem
Ecosystem: a community of organisms and their environment
Terrestrial: living in or relating to the land
Aquatic: living in or relating to water
Diverse: a variety of differences
Fertile: able to grow plants easily because of an abundance of nutrients
Nutrients: substances that provide nourishment for plants and animals (minerals in the soil/food eaten)
Organism: any living thing that can reproduce and grow

|[List 2]|

Population: all of the organisms that belong to one species found in an area
Species: a specific group of organisms that can reproduce
Wastes: an unusable or unwanted substance that is eliminated from an organism’s body
Decomposer: an organism that breaks down dead plant or animal material and returns the nutrients to ecosystem (examples: bacteria and fungus)
Photosynthesis: The process where green plants use sunlight, water, and carbon dioxide to make food (sugars)
Consumer: an organism that must eat to get energy/nutrients
Producer: an organism that can make its own food and provides a source of stored energy for the entire ecosystem

|[List 3]|

Carbon cycle: a natural cycle that involves producers taking in carbon dioxide and releasing oxygen, and consumers taking in oxygen and releasing carbon dioxide
Nitrogen cycle: a natural cycle where decomposers break down dead plant and animal materials and return their nutrients to the ecosystem; plants then absorb these nutrients through their roots and pass the nutrients along until the plant or an animal dies again
Temperate: a moderate climate; not too hot or too cold
Salinity: The amount of salt in a substance like water
Continental Shelf: The underwater edge of a continent
Food Chain: a diagram showing the movement of energy between organisms in a single path according to what they eat
Food web: a diagram showing the interconnecting food chains from an ecosystem
Energy pyramid: a diagram that shows the amount of energy available to be passed from one organism to another when eaten

|[List 4]|

Estuaries: an area where freshwater streams mixes with saltwater from the ocean
Salt marsh: a coastal wetland that is flooded and drained by salt water brought in by the tides; soil is often composed of peat
Ocean: a large body of saltwater that covers over 70 percent of Earth’s surface
Lakes: a body of fresh or salt water that is large, and fed by rivers and streams and ponds
Ponds: a small body of freshwater that is often times formed by humans
Rainforest: an ecosystem located near the Equator that experiences more than 100 inches of rain per year and has tall, broadleaf evergreen trees that form a continuous canopy
Deciduous Forest: an ecosystem that has a moderate climate, four seasons, and trees that lose their leaves in the Fall and grow their leaves back in the Spring
Conifers: Trees that produce their seeds in cones and often have needle like leaves
Grasslands: an ecosystem that does not receive enough rainfall to support the growth of trees but can support various types of grass; also known as prairies, savannas, pampas, and steppes

|[List 5]|

Primary Consumer: a consumer that eats producers in a food chain (herbivore or carnivore)
Secondary Consumer: a consumer that eats the primary consumer in a food chain (carnivore or omnivore)
Tertiary Consumer: a consumer that is in the top trophic level. It normally consists of large carnivores or omnivores
Predator: a consumer that hunts and kills other animals for food
Prey: an animal that is hunted and killed for food
Interdependence: a term describing how organisms depend on each other for survival in an ecosystem
Herbivore: a consumer that only eats producers
Carnivore: a consumer that only eats other consumers
Omnivore: a consumer that will eat both producers and other consumers

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