2.  An ecological system - consists of a living community and all of the physical aspects of its habitat - physical factors are known as abiotic factors and can include: light, temperature, precipitation, soil type, water availability, soil and water pH, etc… - the members of the living community are known as the biotic factors in an ecosystem - the biotic and abiotic factors in an ecosystem influence each other.

3.  Ecosystems rely on energy -The amount of energy available in an ecosystem determines how many organisms can live in that ecosystem

4.  How does energy enter an ecosystem? - Sunlight is the primary source of energy for most ecosystems on earth No sun = No energy No Energy = No Life No Life = BUMMER!

5.  Sunlight needs to be converted to be used in an ecosystem.  Who converts the sunlight? - plants, algae, some bacteria - organisms that convert the energy from sunlight into a useable form are known as producers - How do they do convert the energy? Photosynthesis

6.  Why is it important? - traps the sun’s energy and stores it in a sugar called glucose. - The stored energy is used by living things

7. 6 CO 2 + 6 H 2 O + Energy C 6 H 12 O 6 + 6 O 2 Carbon Water Sunlight Glucose Oxygen Dioxide

8.  Who uses the energy trapped by producers? - All living things use the energy trapped by producers - producers use this energy themselves - Other living things, called consumers eat producers for their energy

9. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + Energy Glucose Oxygen Carbon Water ATP Dioxide Living things break down glucose and the energy stored in it, using a process called cellular respiration

10.  Herbivore – plant eater  Carnivore – animal eater  Omnivore – eats both plants and animals

11.  Photosynthesis  6 CO 2 + 6 H 2 O + Energy C 6 H 12 O 6 + 6O 2  Cellular Respiration  C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + Energy  The two processes are the opposite of each other - the products of one process are the reactants of the other

12.  Divided into Trophic (feeding) levels.  Primary producers/autotrophs  Primary consumers/herbivores-plant eaters  Secondary consumers/carnivores –meat eaters  Tertiary consumers/carnivores  Detritivores/decomposers- vital part of the ecosystem. They recycle abiotic materials from dead organisms – without them, life would stop. - they play a role in nutrient cycling

13. Primary Consumers Producers Detritus Feeders Producers Primary Consumers Secondary Consumers Tertiary Consumers Decomposers

15.  90% of the energy available is lost as energy is transferred to the next trophic level - the energy is lost as heat  Only 10% is of passed on to the next level 100,000 J of sunlight 100 J Rats 10 J Snakes 1,000 J Grasshoppers 10,000 J wheat

16.  Food Chain – the path of energy through the trophic levels of an ecosystem - all food chains begin with a producer

17.  = a series of multiple interconnected food chains. - in most ecosystems, energy doesn’t follow a simple path - many consumers eat at different trophic levels - food webs are a representation of the complex relationships between organisms in an ecosystem

19.  Productivity is a measure of the amount of energy available in a ecosystem  Gross Primary Productivity:–a measure of the total energy captured by plants through photosynthesis  Net Primary Productivity=net primary productivity is the energy available to consumers - the difference between the amount of energy trapped by photosynthesis and the amount used by the plants through cellular respiration

20.  NPP=GPP-Rs NPP =Net Primary Productivity GPP = Gross Primary Productivity -the total amount of sun’s energy trapped and converted into useable form by photosynthesis Rs= Plant Respiration : - the amount of energy consumed by the plant for its own needs Net Primary Productivity is important because it is the energy available to consumers.

21.  12% decline due to deforestation  Use 28 % used for food, building materials, energy  Together 40% of Earth’s NPP is committed to the use of humans.

22. Abiotic factors Food Chain Biotic Factors Food Web Producers Gross Primary Productivity Consumers Net Primary Productivity Photosynthesis- Definition Photosynthesis – equation Cellular Respiration - Definition Cellular respiration-equation Trophic levels Herbivore Carnivore Omnivore Detritivores/ Decomposers

23. Energy Flow Questions 1.Most food chains only have 4 levels. Why? 2.Use your knowledge of energy flow through an ecosystem to explain why we could feed more of the Earth’s people by eliminating meat from our diet.

24.  Assuming all primary plant growth was utilized by humans and no other effects (pollution, disease) are taken into account then the theoretical carrying capacity is  100%/40% x 6 billion people=15 billion