Energy in Ecosystems Notes

Energy in Ecosystems Notes



hey guys mr. Wilhelm here today we are going to discuss energy specifically energy in an environment energy in an ecosystem that is about the Sun and the energy that the Sun provides plants and then also the energy that flows from one organism to the next such as in food chains and in food webs to begin with we're going to review a little bit of vocabulary that you should already know however if you don't then you'll be able to pick this up pretty quickly and for those of you that do know this and it should start bringing things back to you and helping you remember a producer her producer is an organism that can make its own food these are also known as autotrophs Otto Otto is self Otto means it can be done on its own okay if you write an autobiography that means you're about writing a book about yourself an autotroph is an organism that can make its own food these are usually plants they can use the sun's light to create food for themselves these are producers they produce food a herbivore a herbivore is an animal an organism they eat only plants okay herb herbs are plants therefore a herbivore is an organism that only eats plants a carnivore is an organism that only eats animals carne carne means meat okay so a carnivore is an organism that only eats other animals or eats meat an omnivore is an organism that eats both plants and animals humans are omnivores we both plants and animals bears are omnivores they eat plants and animals okay decomposers decomposers are small organisms that break down the remains of dead organisms into simpler substances the decomposers are considered to be different types of bacteria worms fungus and so forth they break down dead organisms decompose dead organisms and those decomposed remains go back to the soil and ultimately those nutrients are used by plants so it kind of completes the whole circle and we'll look at that a little bit more detailed just a second okay so what are some examples of how energy flows through ecosystems there are different levels of energy and where it can be found in and throughout the ecosystem these levels are called trophic levels t ro pH IC trophic levels energy begins with the Sun if you ever see a question about where does the energy start where does everything all the energy in an ecosystem begin it begins with the Sun okay and then energy flows from the Sun to producers with your plants they use the Sun energy to make their own food now producers that is the bottom trophic level the next trophic level is what we call primary consumers okay producers are making their own food consumers have to obtain their food from an outside source they have to eat consumers have to consume they have to eat in order to get their food the first level of consumers the consumers that eat producers are called primary consumers now consumers that eat other consumers consumers that eat primary consumers are called secondary consumers ok secondary consumers eat primary consumers and then this continues on until we get to the top level of consumers those are called tertiary consumers ok this word tertiary tertiary consumers eat secondary consumers okay now a single line like the one you seen right now is called the food chain it's a direct line they're directly links direct links in this chain okay it's a straight line if you will okay that is a food chain that is slightly different from a food web a food web which also includes the decomposers is not just like a simple line like you see here but it is where all of the different organisms start to overlap okay so we have the Sun start off with the Sun energy goes from the Sun to producers in this case phytoplankton phytoplankton or organisms plant type organisms that we find in the ocean okay fish eat the phytoplankton then you have something like a seal to eat the fish then you've got the killer whale or the Orca these the seal all of these things when they are when they die and their bodies start to decompose are broken down by decomposers which in this example are worms right here these are worms not snakes but worms okay and then those nutrients go back to the ecosystem okay so a little bit more about food chains and a food chain it shows how energy is passed from one organism to another the way we show how energy has passed from one organism to the number to the other is by the arrows okay so to begin with I start off with a producer okay start off with a producer now in this case I've got a mouse okay got the mouse the mouse eats the plants okay the mouse eats the plants so all of the food that is in and all the energy that is in that plant goes to the mouse that's the direction the arrow is showing us the arrow is not showing us who eats who the aerial is showing us where the energy is going so all of that chemical energy we study chemical energy before food is chemical energy so all of the chemical energy in the plant goes to the mouse when the mouse eats the plant if we continue on down this single line when the snake okay eats the mouse all of the energy all of that chemical energy in the mouse is gonna go to the snake when the hawk eats the snake all of that chemical energy in that snake is going to go to the hawk so the the arrows show us the direction of energy flow they show us where the energy is going and again not to eat ooh and that can sometimes confuse some people so in this example the plant here is our producer okay we start our food chain with our producer the first in line and the first to eat is what we call the primary consumer the primary consumers are eaten or the energy goes to the secondary consumers the secondary consumers are eaten by the tertiary or all that Energy's going to the tertiary consumers and again we mentioned this earlier producers are also called autotrophs and consumers are called heterotrophs okay producers can make their own food consumers have to get their food from the outside source so producers are called autotrophs consumers are called heterotrophs now the difference between a food chain and a food web is that food webs are simply overlapping food chains food webs are a combination of food chains in a food web I have three four five six different food chains and they all interconnect they all are intertwined okay and a food web or even a food chain prey are the animals that get hunted versus predators are the organisms that are doing the hunting and again the energy shows us the direction that the energy is traveling or the direction that the energy is going so here is a food web so now I don't have a single line of arrows and food chain I have a single line of arrows it's a straight line here I've got arrows going every which direction I've got several food webs mixed together here's a food web and the energy goes from the grass to the caterpillar energy goes from the caterpillar to the lizard and then the energy goes from the lizard to the hawk that's a food chain here I've got the energy going from the grass to the rabbit and then I got the energy going from the rabbit to the hawk that's another food chain okay and then all of a sudden my food chains start to crisscross so if here for example I've got the energy going from the grass to the caterpillar and then all sudden the grass is going from there the energy is going from the caterpillar to the bird so food webs are overlapping food chains and it kind of looks like a web it's a bunch of Criss crossing that's taking place here's an example of a Texas food web this is one we would find around here fish and alligators or our alligators in West Texas or Scooby East Texas East Texas butterflies birds rabbits okay beetles and so forth so let's look at the different parts of this particular food web so looking right now which of these organisms are producers or autotrophs okay in this example I've got three I've got the leaves up here I've got the algae algae is a water plant water autotroph and I've got the sunflower so those are my three producers and the Texas food web okay which of these guys are primary consumers remember primary consumers are the first in line they're the ones that are gonna eat the producers now I can go ahead and look at my arrows where my arrows at well I've got arrows going from the sunflower to the cricket the arrows going from the sunflower to the beetle got arrows going from the leaves to the rabbit and also the leaves to the cricket there's my energy flow and the leaves to the butterfly I've got the arrows going from the algae to the fish so which one of these would you think would be the primary consumers it's where the energy is going it's going from the producer to the primary consumers and there we have it the ones we already identified okay we got the cricket and the rabbit and the butterfly the beetle and the fish then we have secondary consumers secondary consumers are the ones that are eating the primary consumers again look for your arrows going from the primary consumers to the secondary consumers so here for example I've got the beetle being a primary consumer and the energy is going to the Frog and the rabbit being a primary consumer and the energy is going to the snake okay and I've the fish being a primary consumer and the energy goes into the alligator okay and I've got some others such as the butterfly being a primary concern and going to the bird so which of these are secondary consumers again the one we identified now you're gonna say well you had the energy going from the rabbit to the snake and you had the energy going from the fish the alligator so what are those guys well those guys are our tertiary consumers these are the guys that are on top of the food web on top of the food chain okay they pretty much eat everything else and you'll start to see that sometimes a top-level consumer will eat a producer us for example humans for example we're not only tertiary consumers but we're also primary consumers we eat lettuce and we eat different plants and vegetables and so forth but we also eat meat we're at the top of our food chain and food web but we do eat primary producers so we can can be considered to be tertiary consumers we can be considered also to be primary consumers so there's not always one way there's multiple ways to look at it okay energy pyramid now you gotta pay attention cuz this is a little bit more difficult to understand now an energy pyramid shows us how much energy is transferred from one level such as a producer level to the next level okay such as a primary consumer level how the energy gets transferred from one trophic level to the next trophic level okay only about 10% of the energy gets transferred from one trophic level to the next now why is it not a hundred percent well because the other ninety percent of energy escapes into the environment in the form of sweat and perspiration waste respiration release of heat a lot of it is in the form of heat so whenever energy is transferred from the grass to the cricket that energy transfer is not 100 percent clean so the energy is essentially wasted or lost only 10% of that energy goes on so if we looked at what we call a food pyramid or an energy pyramid you see that the vast majority of the energy and the energy pyramid pyramid is at the bottom in the producer level down here at the bottom that's in the form of trees and grasses that's where the vast majority of the organisms on earth are also located there are more plants on this earth than any other type of animal now as we move up the pyramid you're gonna see that the levels of the pyramid get smaller because some of that energy is being lost so there's more energy in the producer level the bottom level then there is at the okay next level up which would be herbivores okay our primary consumers that level is a little bit smaller as we continue to move up okay to our secondary consumers okay our triangle our little piece of the pie gets a little bit smaller and then when we get to the top the triangle is the smallest that's where there's the least amount of energy every single time we go from one trophic level to the next so we start here at the bottom every single time we move up the energy pyramid okay only 10% of that energy is moving upwards the other 90% is being lost into the environment heat okay into the environment so the energy pyramid shows us where all the energy is which is in the peruse level and it also shows us while the energy is not which is at the tertiary consumer level the highest level consumer and that's also where they have we have the fewest levels or the fewest number of consumers there's fewer tertiary consumers than there are any other type of consumers okay there's way more producers than there is tertiary consumers there's also way Mary more primary consumers and remember primary consumers can also be like insects okay and birds and rabbits and all those small lizards and reptiles and animals so there's way more primary consumers than there are tertiary consumers so that is the energy pyramid big thing to remember here is that as you go up the levels get smaller because not all the energy is transferred from one level to the next energy is lost when those things eat each other all right so let's do a little bit of a learning check see how we're doing at this point so here is a food web okay it's a desert food web okay in this part Joshua Tree National Park which organisms are both secondary and tertiary consumers in this desert food web so you're looking at the energy and where the arrows are pointing we're looking for secondary and tertiary so which organisms are both okay so if I answer this question I can go ahead and look at the bottom the Joshua Tree that's gonna be my producer okay now the wood rat and then also the termite they are eating that producer the energy is going from the Joshua Tree to those organisms so those guys are primary consumers okay now the snake and the lizard okay the snake energy is going from the wood rat to the snake energies going from the termite to the lizard so these guys are secondary consumers okay and then we have the hawk this guy is on top so therefore he is our tertiary consumer so the question is asking which organisms or organism is both secondary and tertiary well we know that the hawk is on top he's our tertiary consumer okay that Hawk is our tertiary consumer but if you look at this look at this right here the hawk also also eats the woodrat it skips the snake right there it also eats that wood rat so that would also make the hog a secondary consumer so the hawk is a secondary second in the line here's producer primary secondary and then he's also a third in line which make him to tertiary primary excuse me producer primary secondary tertiary here's another question using the same food web what would happen if the lizard population became extinct if we took the lizard out of this scenario he's gone what would you think would happen to this particular food web look at what the lizard eats and also look at what eats the lizard okay you have the hawk the hawk eats the lizard but is that the only thing the hawk eats no that's not the only thing he eats but he does eat the lizard okay if he took him out with the hawk starve to death probably not because the hawk has still got the snake the hawk has still got the wood rat okay what about the moth okay the lizard eats the moth what happens if there's nothing around to eat the moth or there's nothing around to eat the termite okay let's look and see what happens in that particular situation so the hawk and the snake population would probably decrease now they wouldn't go out an extinct but the hawk and the snake are losing a food source okay the hawk and the snake both eat the lizard the energy goes from the lizard to both of those guys so if lizards died out there'd be a slight decrease in probably the hawk and snake population there's not as much food also the termite mouth population would probably increase because there's nothing to eat the tert the the termite and the moth okay they don't have a predator anymore there's nothing to keep them in check so the termites and moths are gonna be living really really well because they won't have to worry about getting eaten because they're eaten primarily by the lizard so their population is gonna be getting the opportunity to get later increase because there won't be anything eating them okay cycling matter now matter is anything that has mass and takes up space okay cycling means reusing so we're reusing matter okay so on this example we're talking about how energy is flowing and matter is flowing from one organism to the next it's another term that we give a food web it's a whole circle cycling means going around and around and around so on both these diagrams you can see how the arrows are making the circled arrows go around and around and they're all interconnected there's no really starting point there's no really stopping point okay thus it's a cycle it continues on and on like the water cycle it goes on and on and on where do you say there's a start at the starting point of a little water cycle is it when it rains or is it when it evaporates neither okay it continues so there's no starting point no stopping point it continues over and over again biomass now you've seen this word bio before okay we've talked about this word bio bio means life okay so mass that deals with life biomass is a renewable energy source from biotic factors biotic biotic are living factors okay such as plants and animals okay usually thought of as being as trash coal petroleum gasoline these are all materials that come from living things therefore we call them biomass okay it's it's energy it's like using firewood okay burning corn corn is also when you break it down you might see it in some cases is also known as ethanol okay corn turning corn into a fuel for cars that's biomass using living resources living material things for fuels to either power our cars or warm our homes or whatever it may be that's biomass some examples of biomass are wood crops garbage okay alcohol fuels which come from grapes and other fruits and vegetables okay so these are all types of biomass there are substances that we can use living substances that we can use in the environment as a fuel okay decay we know what decay means decay means to rot okay to breakdown you have decaying banana it's a rotting banana okay decomposers help in this process decomposers help things make things decay decomposes break down organisms into simpler substances decomposers would be things such as bacteria fungus earthworms beetles these are all animals or organisms that break down the dead remains of plants and animals okay they cause things of decay if we didn't have bacteria and fungus and these different things to cause organisms to break down then organisms would not rot organisms plants and animals both would not break down we'd have dead organisms all over the place I know that sounds kind of nasty but we need decomposers to break down the bodies of dead plants and animals so that they will go back to the soil so they could continue the whole cycling process so that those nutrients from those organisms can be continued used again and again again remember whatever is here on this planet has been here Cayenne will continue to be here it's just going in a circle okay it's growing it's being the food for something else it's decomposing and going back to the earth okay that's the whole cycling process and decomposers cause decay and the breakdown of these dead organisms very important compost now composting is when something collects some living factors biotic factors okay and they decompose and then we use that decompose matter for our own benefit okay you might have a composting bin or know somebody that might have a composting pile in the their backyard it's where you put banana peels and leaves and grass clippings and you put them in this bin and then they start to break down into this material okay this composting material that we can use as a fertilizer that's a natural fertilizer plants grow wonderfully in this stuff okay and also we're recycling these materials this is usually called houmous okay it's a report it's a result of composting it's a dark soil light mixture okay very very very high in nutrients that we can take materials and we can essentially reuse them it can recycle them and use them again so that banana peels stead of throwing it into the trash can into that plastic garbage bag you could put it in your compost bin and over time a couple months it'll break down and it'll turn into this nutrient-rich soil that I could use to fertilize flowers or you could use the fertilizer the plants okay composting it's a way to reuse the the materials that we have here's an example of a composting bin you might find in your backyard okay it's just a pile some are enclosed we have composting bin outside of the school that we're gonna take a closer look at has all these dead materials in them they're broke broken down and they don't stink they don't smell there's no odor it's very very clean okay because all that deccan decaying and rotting material it's not rotting anymore it's broken down to the final process okay it's gone back to the earth in a soil like material so they can be used to recycle and continue the cycle for plants and so forth organisms help in the composting process such as worms like in the picture worms if you have a composting bin you'd added worms and other microorganisms to work on that composting process and they help break down those materials okay so that will do it for our energy and ecosystems notes I hope you payed attention obviously if you need to go back and listen to something again I hope you do so

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4 thoughts on “Energy in Ecosystems Notes

  1. Isn't the snake also a tertiary consumer (the question did say organisms so there should have been at least two) if it ate the lizard, after the lizard either ate the moth or the termite

  2. thank you so so soooo much i cant thank you enough i was having trouble understanding this stuff but you made it so easy. i am all ready for my midterm tomorrow thank you 

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