Energy Transfer p

Transcription

1 Energy Transfer 22-1 p

2 Essential Questions 1. Identify and describe the main types of producers and consumers in an ecosystem. 2. Calculate the amount of energy stored in biomass transferred from one trophic level to another based on a four level energy pyramid with 100 kilograms of energy available at the producer level. 3. Explain why the number of individuals in a population decreases as they get higher in the food chain.

3 Energy Transfer the passage of energy through the components of an ecosystem Organisms need energy for: Growth Movement Maintenance & repair Reproduction Energy flows through an ecosystem continuously Energy comes from the sun Photosynthesis coverts sunlight into chemical energy (food) Organisms use the energy to live & release energy as heat Energy is not recycled in ecosystems

4 Producers are organisms that make food for themselves & everyone else Autotroph is another term for producer! Types of producers: Photosynthetic (most common) use sunlight to make food Chemosynthetic use energy from molecules to make food Producers

5 Biomass Biomass is amount (or mass) of organic material in an ecosystem This is measured by the amount mass of all of the organic material in an organism, a trophic level or an ecosystem

6 Measuring Productivity Productivity of an ecosystem can be measured by how much energy is captured from the sun and converted into food Gross Primary Productivity (GPP) the rate at which producers in an ecosystem capture energy Net Primary Productivity (NPP) the rate at which biomass accumulates (GPP the respiration rate) Primary Productivity: Varies between different ecosystems Sets the energy limit for the entire ecosystem

7 Consumers Consumers must eat food made by other organisms (they cannot produce their own food) Heterotroph is another word for consumer Types of consumers: Herbivores eat producers Carnivores eat other consumers Omnivores eat producers and other consumers Detrivores eat decaying material (plant matter, animal waste, etc) Decomposers eat dead material & cause decay Decomposers make organic materials available to producers!

8 Energy Flow Energy flow diagrams are ecological models representing how energy moves through an ecosystem Trophic levels indicate an organism s position in the sequence of energy transfers

9 Trophic Level Pyramid Producers (autotrophs) photosynthetic organisms that make their own food Primary consumers herbivores that consume producers Secondary consumers small carnivores or omnivores Tertiary consumers large carnivores or omnivores Quaternary consumers top of the food chain (not always present) Decomposers & Detrivores organisms that consume dead or decaying Usually bacteria and fungi

10 Food Chain the sequence of food transfer from organism to organism

11 Food Webs shows all of the feeding relationships in an ecosystem Arrows show the direction of energy flow

12 Energy Pyramids show the cumulative loss of energy from a food chain 10 % of the energy is passed on to the next level 10% is the ecological rule of thumb There is some variation in different ecosystems 90% if the energy is: used by the organism to sustain life (through cellular respiration) lost as heat & waste

13 Humans in the Food Web Omnivores consume both plants & animals Primary Consumers when we eat grains, fruits, veggies & legumes Secondary Consumers when we eat beef, chicken & other herbivores Tertiary or Quaternary Consumers when we eat fish & other carnivores

14 Essential Questions 1. Identify and describe the main types of producers and consumers in an ecosystem. 2. Calculate the amount of energy stored in biomass transferred from one trophic level to another based on a four level energy pyramid with 100 kilograms of energy available at the producer level. 3. Explain why the number of individuals in a population decreases as they get higher in the food chain.