- Slides: 58
Ecosystems Part 1
• An ecosystem includes all of the organisms as well as the nonliving things in a given area. Ecosystem Community Population Organism
• A community is a group of different species that live together in one area. Community Population Organism
An ecosystem includes both biotic and abiotic factors. anything that is LIVING is considered biotic. Examples: plants animals fungi Bacteria plants
Abiotic factors are nonliving things. – anything that is NON-LIVING is sunlight considered abiotic. Examples: – moisture – temperature – wind – sunlight – Soil – https: //www. youtube. com/watch? v=E 1 pp_7 -y. TN 4
Carrying Capacity and Limiting Factors
Carrying Capacity What exactly is carrying capacity? Carrying capacity refers to the number of individuals a certain habitat or area can support given the resources that are available
Carrying Capacity All animals need basic things to survive and they must get these things from their habitat Animals need Food Water Shelter Space
Carrying Capacity No matter where you are on planet Earth, there will be some resources that are in short supply For In instance: a desert water is very scarce and hard to find In a rainforest space is limited In the mountains food might be hard to come by
Carrying Capacity: Home Life Think about your home Everyone might have their own bed, a place to put their clothes, enough food to eat and water to drink, as well as an area they can go to and relax
Carrying Capacity: Home Life Now imagine that 5 people moved in What would happen? What would happen if 10 people moved in? How about 30 people?
Carrying Capacity: Home Life Just like in nature, your home has a carrying capacity: a certain number of individuals that can live there and still find everything they need Once you go above that number, life becomes very difficult!
All Habitats Have a Carrying Capacity All places have a certain number of individuals that can live there and still gain everything they need Once the number of individuals pass that number, life gets harder and harder
Ecosystems Limiting Factors
Let’s suppose…. We have two mice…: and they produce the standard 56 “pups” (baby mice) each year. and each of these mice goes on to have 56 babies each year….
Soon…. . We’d be over-run with mice on the planet!! Why doesn’t this occur?
Limiting Factors A limiting factor is an abiotic or biotic factor that limits the number of individuals in a population.
Limiting Factors Limiting 1. 2. 3. 4. factors can include: Space Food Water Disasters: fire, flood, drought, disease
SPACE Human activities play a large role Development, damming rivers, clear cutting forests.
Predators: Food As the prey population increases, the predator population increases. As the prey population decreases, then so does the predator population.
Example: Lynx and Hare:
Disaster: Drought If a drought comes along, the water supply goes down. The number of animals living in or near the water would decrease because there would not be enough water to support a larger number of animals.
https: //www. youtube. com/watch? v =8 FPMP 41 LYJ 8
Part 2: Producers and Consumers
Producer Makes food by changing light energy of the sun into chemical energy, or food Also called Autotrophs Ex. Plants, algae, some bacteria
Consumers Organisms that do not make their own food Also known as HETEROTROPHS Ex. Rabbits, Deer, Mushrooms
Heterotrophs Consumers A. Herbivores – eat ONLY plants Ex. – Cows, Elephants, Giraffes
Heterotrophs Consumers B. Omnivores – eat BOTH plants and animals Ex. – Bears and Humans
Heterotrophs Consumers C. Carnivores – eat ONLY other animals Ex. – Lions, Tigers, Hawks https: //www. youtube. com/watch? v=O_ 4 Hoz. C 8 qww
Heterotrophs Consumers D. Scavengers/Detritivores – feed on the tissue of dead organisms (both plants and animals) Ex. – Vultures, Crows, and Shrimp
Heterotrophs Consumers E. Decomposers – absorb any dead material and break it down into simple nutrients or fertilizers Ex. – Bacteria and Mushrooms
Part 3: Food Chains https: //www. youtube. com/watch? v=Cd 1 M 9 x. D 482 s
Food Chains The energy flow from one trophic level to the other is know as a food chain. 1. The SUN begins ALL food chains. 2. Next, are the PLANTS, AKA Primary Producers 3. After producers are PRIMARY CONSUMERS 4. Then, SECONDARY CONSUMERS 5. Next, the TERTIARY CONSUMERS Some food chains will go to another level, but most don’t go beyond four levels. ALL food chains end with DECOMPOSERS.
Each step in a food chain is called trophic level a ______. The trophic level indicates: the organism’s position in the sequence of energy transfers. Trophic Level The first trophic level in a food chain is always made up producers of _____. These organisms are referred to as primary producers _________. The second trophic level is occupied by the _____ herbivores producers that feed on the _____. These organisms are Primary consumers referred to as _________.
Trophic Levels (feeding levels) Secondary Consumers (carnivores or omnivores) Primary consumers (Herbivores) Primary Producers (Autotrophs)
__________ Predators of herbivores belong to the third level. These organisms are referred to as: secondary consumers. Each consumer depends on the: trophic level below it for energy. Most ecosystems contain only ______ three or four trophic levels.
Trophic Levels: Primary Producer, Primary Consumer, Secondary Consumer, Tertiary Consumer? Grass Mouse Grasshopper Frog Owl Hawk
Trophic Level: Producer, primary consumer, secondary consumer, tertiary consumer Grass Producer Mouse Primary consumer Grasshopper Primary consumer Frog Secondary consumer Owl tertiary consumer Hawk Secondary consumer
Part 4: Food Webs http: //studyjams. scholastic. com/studyjams/ja ms/science/ecosystems/food-webs. htm
Food web: The network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem. A food web links all the food chains in an ecosystem together.
In an ecosystem, the feeding relationships between organisms are much too complex to be shown in a …. . single food chain. Food Webs There are many complex interactions between many different food chains. Many consumers eat: more than one type of food. More than one species may feed on: the same organism.
A QUICK REMINDER…
What is the primary source of energy for an ecosystem?
What do the plants do with the glucose they produce? half of the glucose About ____ is used immediately in cellular respiration _________. Respiration is the conversion of: glucose into molecules of ATP, the energy source for a cell. Some of the glucose molecules are used as raw materials (building blocks) for the building of other _______ organic compounds within the cell. Much of the glucose is…. . stored by the plant for future use.
Part 5: Energy Pyramids
Energy Transfer Between Trophic Levels The amount of energy or matter in an ecosystem can be represented by an: …. . ecological pyramid. Ecological pyramid: A diagram that shows the amount of energy contained within each trophic level in a food chain or a food web.
Roughly 10% ____ of the total energy _____ consumedin one trophic level is passed to the next trophic level organisms in the ________. The pyramid shape of the diagram to the right represents the low percentage of energy transfer from one trophic level to the next.
Why is the transfer of energy to the next trophic level so low? energy possessed by the organisms at one trophic level Not all of the ______ passed up to the next trophic level. will be _______ consume for their own use much of the energy they ____ Organisms ____ life processes such as respiration, movement, or reproduction. ______ Many organisms at one trophic level will escape being eaten _________ by the _____ predators at the next level. The energy _______ of these “_______” escapees will not be passed to the organisms at the higherlevel. _______
The following is a hypothetical food chain: grass ---> grasshopper ---> toad ---> black snake The grass occupies what trophic level? It is the producer. The grasshopper occupies what trophic level? The grasshopper is the primary consumer. The toad occupies what trophic level? Secondary consumer The black snake occupies what trophic level? Tertiary consumer If the energy content of grass is approximately 5, 000 calories per square meter of land surface, then the energy content of the black snakes should be approximately how many calories per square meter? Answer: About 5 calories per square meter.
The low rate of energy transfer between trophic levels explains why: food chains rarely contain more than a few trophic levels. Organisms occupying the lower trophic levels are usually much abundant than organisms more _____ belonging to the highest level. There are many more grasses, shrubs, and trees than there are herbivores _____. There are many herbivores (deer, antelope, gazelles) for carnivore (lion) each _______. Higher trophic levels energy and contain less ______, therefore, they can support individuals fewer _____.
Transfer of Energy When a lion eats a zebra, it does not get all of the energy from the zebra (much of it is lost as heat) Only 10% of the energy from one trophic level is transferred to the next – this is called the 10% rule https: //www. youtube. com/watch? v=Scizkx. Ml. E OM
Ecological Pyramid • • Which level has has the the most energy? most organisms? least energy?
Three hundred trout are needed to support one man for a year. The trout, in turn, must consume 90, 000 frogs, that must consume 27 million grasshoppers that live off of 1, 000 tons of grass. -- G. Tyler Miller, Jr. , American Chemist (1971)