Food Chains and Food Webs DO NOW TUESDAY

+ Food Chains and Food Webs

+ DO NOW TUESDAY n Create a food chain using the following organisms:

n. TODAY’S • To describe the transfer of energy in relationships. n. TODAY’S • • PLAN DO We will watch a video: “Of Ice and Fire” and answer questions about the video. We will write some definitions of food chain vocabulary on our glossary sheet.

+ DO NOW THURSDAY n Observe both the aquatic and terrestrial ecosystem for your group. Person 2 in each group should fill out the information for your ecosystem only. n DO NOT MOVE THE ECOSYSTEMS from the place where they have been put because we need to observe the natural behaviors of these animals.

n. TODAY’S • To describe the transfer of energy in relationships. n. TODAY’S • • • PLAN DO We will complete the Pond Ecosystem Gizmo with your table partner. This Gizmo must be completed today. You will receive a grade for this Gizmo.

+ DO NOW FRIDAY n Create a food chain using the following organisms: Raccoon Algae Small fish Phytoplankton Big fish

n. TODAY’S • To describe the transfer of energy in relationships. n. TODAY’S • • PLAN DO We will discuss food chain and food web vocabulary. You will create a food web for the Mono Lake Ecosystem. You will draw the food web and label each organism in the food web as a producer, consumer, or decomposer. You will label each consumer as an herbivore, carnivore, or omnivore.

+ What are we learning? n We are learning about food chains and food webs in ecosystems. n Food chains and food webs show us feeding relationships and, therefore, how energy moves from organism to organism in an ecosystem. n Food chains and food webs show us how all things in an ecosystem and on Earth are dependent upon each other for survival. n They also allow us to predict how a change in one part can affect all of the other parts of an ecosystem.

+ Why are we learning this? n We need to learn about food chains and food webs because we are part of them. n We need to know how we depend upon other organisms for survival and they depend upon us. n We need to know this so we can be more aware of how things that we do can affect our environment. n We need to be more conscious of our activities so we might make better choices when we do things that alter our environment. n Can you give some examples of things you do that affect the environment (negatively or positively)?

+ What is a food chain? n Shows the feeding relationships in an ecosystem.

+ What is a food web? n Shows interconnected food chains in an ecosystem. n Is a better representation of the feeding relationships in an ecosystem

+ What about the arrows in a food chain or food web? n The arrows point in the direction of energy flow. n This means that the arrows point to the organism that is DOING THE EATING, since it is the one that is getting the energy.

+ What kinds of organisms are in food chains and food webs? n There are 3 basic kinds of organisms in food chains and food webs. n Producers n Consumers n Decomposers

+ Producers n Produce their own food (usually through photosynthesis) n Are at the bottom of a food chain n Includes plants, algae, etc.

+ Consumers n Have to eat other organisms n Are in the middle and at the top of the food chain n Includes animals that eat plants or other animals

+ Decomposers n Break down dead organisms and return their nutrients to the environment n Includes fungi (mushrooms, etc. ) and bacteria

+ What types of consumers are there? n There are 3 different kinds of consumers: n Herbivores n Carnivores n Omnivores

+ Herbivores n Eat only producers (plant materials)

+ Carnivores n Eat only other animals (meat)

+ Omnivores n Eat both plants and animals

+ Rules for Creating Food Chains and Food Webs n Always begin your food chain/web with a producer. draw the arrows so that they point to the organism that is DOING THE EATING, since this is the direction of energy flow in the feeding relationship. n Always n Assignment: • • • You will create a food web for the Mono Lake Ecosystem. You will draw the food web and label each organism in the food web as a producer, consumer, or decomposer. You will label each consumer as an herbivore, carnivore, or omnivore.

+ Food Chains and Food Webs Involve Us All!!

+ DO NOW MONDAY n Observe both the aquatic and terrestrial ecosystem for your group. Person 3 in each group should fill out the information for your ecosystem only. n DO NOT MOVE THE ECOSYSTEMS from the place where they have been put because we need to observe the natural behaviors of these animals.

n. TODAY’S • To describe the transfer of energy in relationships. n. TODAY’S • • • PLAN DO We will review the Mono Lake Food Web you drew on Page 3 of your packet on Friday. We will discuss energy transfer and the energy pyramid of a food chain/web. We will create our own energy pyramid for a food web and label it.

+ MONO LAKE FOOD WEB Halobacteria (Decomposers) Planktonic Algae (Producer) Brine Shrimp Eared Grebe Red-necked Phallarope Wilson’s Phallarope California Gull Benthic Algae (Producer) Brine Flies Snowy Plover Coyote Caspian Tern

+ Energy Transfer in Food Chains and Food Webs n When one organism eats another, energy is transferred from the one who was eaten to the one who did the eating. n For example, when a snake eats a mouse, energy is transferred from the mouse to the snake.

+ Energy Transfer in Food Chains and Food Webs n However, the snake doesn’t get 100% of the mouse’s energy. n Only 10% of the energy from the mouse gets passed on to the snake. n The other 90% of the energy that was in the mouse was used by the mouse to live and/or released as heat from the mouse’s body.

+ Energy Transfer in Food Chains and Food Webs

+ Energy Pyramid Activity

+ Materials n 1 pair of scissors n Tape n 1 roll adding machine tape n 1 meter stick n Sharpie

+ Information n For this lab 1 mm = 1 kcal (kilocalorie) of energy! n Remember only 10% of energy is passed up through the trophic levels.

+ Step one – Producer Level n Cut a strip of adding machine tape 1, 000 mm (1 m) long. n This represents 1, 000 kca of energy. n In the middle of the adding machine tape label it “Producers” with the sharpie.

+ Step two – 1 st Level Consumers (Herbivores) Also call Primary Consumers n Only 10% of the energy is passed from the producer level to the primary consumer level. So…. . n 10% =. 1 n 1, 000 mm X. 1 = 100 mm (10 cm) n Our 1 st Level Consumer strip needs to be 100 mm long. n Cut a strip 100 mm long and label it “ 1 st Consumers” with the sharpie.

+ Step Three – 2 nd Level Consumers (Eat 1 st Level Consumers) Also called Secondary Consumers n Only 10% of the energy is passed from the primary consumer level to the secondary consumer level. So…. . n 10% =. 1 n 100 mm X. 1 = 10 mm (1 cm) n Our 2 nd Level Consumer strip needs to be 10 mm long. n Cut a strip 10 mm long and label it “ 2 nd Consumers” with the sharpie.

+ Step Four – 3 rd Level Consumers (Eat 2 nd Level Consumers) Also called Tertiary Consumers n Only 10% of the energy is passed from the secondary consumer level to the tertiary consumer level. So…. . n 10% =. 1 n 10 mm X. 1 = 1 mm n Our Third Level Consumer strip needs to be 1 mm long. n Cut a strip 10 mm long. You cannot label this. It is too small!

+ Step five – tape it all together n Tape all of this together and attach to a sheet of poster paper!!!!

+ Step Six – Finish Labeling n First title your model “Energy Pyramid” n Next, label your 3 rd Level Consumers.

+ Step six Continued – Add Organisms n Use this food web as reference. n Draw the organisms on the appropriate trophic level!

+ DO NOW TUESDAY n Create a food web with the following organisms: grass mouse fox owl grasshopper snake rabbit

n. TODAY’S • • Describe limiting factors. Explain environmental limiting factors that influence the growth of populations. n. TODAY’S • • PLAN DO We will create a class food web and answer questions. We will discuss limiting factors and carrying capacity.

Factors that Affect Population Size + in an Ecosystem n There are many factors that affect how large a population can become. n Can n n you think of any? Predators Natural disasters Availability of food, water, shelter Disease Human Activity n Things like these that keep a population from growing out of control are called LIMITING FACTORS.

LIMITING FACTORS KEEP A + POPULATION AT ITS CARRYING CAPACITY n Carrying capacity is the maximum number of individuals that the resources of an ecosystem can support. n When a population is at its carrying capacity, the birth rate and death rate in the population are about the same so the population remains a stable size. n Limiting Factors keep a population at its carrying capacity.

+ Limiting Factors and Carrying Capacity

+ CARRYING CAPACITY

Practice + Problem Q: What’s the carrying capacity of this population? A: Around 65 rabbits Q: When did this population reach its carrying capacity? A: Around August 1