2 Energy and matterThe Earth has internal (chemical) and external (solar) energy.That energy is used to move matter through the Earth’s systems.Energy changes the physical and chemical properties of matter.
3 Sustaining Life on Earth Requires Energy and Matter One-way flowof EnergySunChemicalsCyclingof Matter
4 Energy in Living Systems Living systems use energyEnergy used for growth, reproduction and metabolismNo organism can create energyCan store it, but not create it
5 Ecosystem energy flow Energy enters an ecosystem in 2 ways: Energy is “fixed” (stored in tissues) by organisms and moves through food webs.Heat energy is transferred (air, water, soil convection) and warms life on Earth.
6 Sunlight is primary source of energy for most life on Earth Exception: Chemicals used in deep sea vents
7 Primary ProducersPrimary producers capture sunlight or chemicals and convert it into useable energy.These organisms are called “autotrophs.”
8 Primary ProducersPrimary producers use solar or chemical energy to make complex organic compounds out of inorganic materials.Primary producers store energy.Used for their own energy needsAlso used by organisms that consume them
9 Primary ProducersPrimary producers include plants, algae and certain bacteria.Use eitherPhotosynthesis: use solar energy to make carbohydrates; release oxygenPhytoplankton (aquatic autotrophs) account for 50% of the oxygen producedChemosynthesis: use chemical energy to make carbohydrates
10 Consumers = heterotrophs Consumers (heterotrophs) rely on other organisms for energy and nutrients.Different types of consumers are classified by the way they get energy.
11 Types of Consumers: Carnivores Carnivores kill and eat other animals.The process of obtaining meat requires energy but meat is generally high in energy and nutrients and is easy to digest.
12 Types of Consumers: Herbivores Herbivores obtain energy from plants: roots, leaves, stems, seeds or fruits.Examples include koalas, cows, rabbits and deer.
13 Types of Consumers: Omnivores Omnivores eat a variety of foods including both plants and animals.Example: Bears eat other animals but also eat berries and other plant products.
14 What about the human diet? Humans who are vegans (plant products only) can be considered _______________.What about vegetarians who eat milk products? ___________________Humans who eat meat and fat only can be considered____________.Humans who eat meat, vegetables and fruit can be considered ________________.
15 Types of Consumers: Scavengers Scavengers eat animals that have been killed by other animals or have died of other causes.Vultures are scavengers.
16 Types of Consumers: Detritivores Detritivores help decompose organic matter by consuming detritus: dead animal and plant parts and organic wastes.Commonly digest decomposers that live on or in detritusEarthworms are detritivores.
17 Types of Consumers: Decomposers Decomposers chemically break down organic matter and use it for energy.Release inorganic compounds into soilDecomposers include bacteria and fungi.Mushrooms are types of fungi.
19 Energy Flow in an Ecosystem: Food Chains and Food Webs Energy flows through an ecosystem in one direction -- from producers to various levels of consumers.Producers and consumers are linked through feeding relationships.
20 Energy Flows Through “Trophic Levels” Each step of a food web or food chain is called a trophic level.Energy flows up from one trophic level to the next.
21 Trophic Levels First Trophic Level Second Trophic Level Third Trophic LevelFourth Trophic LevelProducers (plants)Primary consumers (herbivores)Feed directly on producersSecondary consumer (carnivores)Feed on Primary ConsumersTertiary consumerFeed on other carnivores
22 Food ChainsFood chains are the series of steps through which organisms transfer energy by eating or being eaten.Can be short or long
23 Food Webs Food Web = more complicated network of feeding interactions Include interconnected food chainsRemoval of one organism affects all other members of the web.Remember: Decomposers and detritivores play animportant role by releasing organic nutrients that canbe used by the primary producers.
24 Identify three food chains within this food web. Which is shortest?______________Which is longest?Describe thepossible effectsof a grasshopperextinction.Note: Energy flows in the directionof the arrow.
25 Ecological PyramidsDiagrams used to show the relative amounts of energy or matter in each trophic level of a food chain or food web.Three types:Pyramids of EnergyPyramids of BiomassPyramids of Numbers
26 Pyramid of EnergyShows the relative amount of energy available at each trophic level of a food chain or food web
27 Pyramid of Energy: 10% Rule As energy is transferred up to the next trophic level, 90% of the energy is lost.Only 10% of the energy within one trophic level is transferred to the next level.
28 Pyramid of Energy: 10% Rule Example: A bird (1st consumer) eats plant seeds (primary producer).Only 10% of the energy in the grass will be stored in the tissues of the bird.How much of the energy from the grass will be stored in the tissues of the hawk that eats the bird? ___________________
29 Pyramid of BiomassThe total dry mass of organisms in a trophic level is its “biomass”.A pyramid of biomass shows the relative amount of organic matter at each level.Most at primary producer level; least at the top trophic level
30 What does this say about the amount of primary producer biomass required to support tertiary consumers?
31 Pyramid of NumbersShows the relative number of individual organisms at each trophic levelGenerally follows the same pattern as the pyramid of biomass