Exploring Biodiversity & Interdependence
Eagle School is fortunate to be located near a variety of ecosystems - prairie, woodland, marsh and pond - that we've explored and investigated over the years. Our aim has been to get to know how diverse nature is by mapping out, drawing and listing the community of organisms we find within those different and neighboring ecosystems. Perhaps we’ll only see evidence that organism has visited or lives in this space. Or we may capture an image of more elusive species by the pond as they trigger our field camera. In this unit, we'll also try to untangle the relationships among the variety of organisms we find and understand how they are dependent upon one another. How do these organisms get the 5 things they need to survive and reproduce in their habitat, and how might they provide it to the other organisms in the same ecosystem?
Below you'll find A LOT of reading material. I used to keep it short, but found that students needed more explanation. We'll be discussing this in class, but I hope that the reading will be helpful to your understanding. There are also 3 videos and an interactive game that introduce you to the idea of biodiversity and interdependence. You are required to watch the video and click on the interactive called "What's the Big Idea about Biodiversity." Bill Nye and Life in the Dzanga Bai are optional.
Below you'll find A LOT of reading material. I used to keep it short, but found that students needed more explanation. We'll be discussing this in class, but I hope that the reading will be helpful to your understanding. There are also 3 videos and an interactive game that introduce you to the idea of biodiversity and interdependence. You are required to watch the video and click on the interactive called "What's the Big Idea about Biodiversity." Bill Nye and Life in the Dzanga Bai are optional.
Questions
- What is biodiversity?
- LIST & DEFINE the 3 types of biodiversity, and GIVE EXAMPLES of each type.
- The "3 Levels of Biodiversity" interactive discusses "species interdependence." They explain how one form of species interdependence involves the habitat resource, Food, and can be demonstrated in food chains and webs. Can you think of a different habitat resource where organisms in a particular ecosystem depend on each other? Provide an example of species interdependence that involves a habitat resource other than food and EXPLAIN it. Please do not include humans in your example.
- LIST the main cause(s) of biodiversity loss right now and EXPLAIN how this is reducing biodiversity.
- Remembering that biodiversity is “VARIETY of life,” EXPLAIN a) why an ecosystem that is higher in biodiversity is important and b) why should this variety of life be protected?
When answering Part (a) of this question, focus on telling me why the variety of life is a GOOD thing! What are the benefits of greater biodiversity?? Over the years I’ve noticed that students focus on catastrophic losses of species due to global effects. Please DO NOT tell me why having less biodiversity is a bad thing in Part (a). While this is indeed occurring, I want you to think about a normal ecosystem and why genetic variation and species variation is important. Focus on the positives of biodiversity!! In (b) you can tell me why protecting that variety is important and, yes, you can tell me the consequences of not doing so.
Introduction to Biodiversity & Interdependence
Three Types of Biodiversity
Species biodiversity: The total number of different species in a given area
Ex. The total number of species that live in the school prairie, such as milkweed, big bluestem, grasshoppers, ladybugs, Monarchs, 13-lined ground squirrels and hawks. Genetic biodiversity: The genetic differences within a single species Ex. Different eye color in Canis lupus Ecosystem biodiversity: The different types of ecosystems in a given area Ex. The area around Eagle school has woodland, prairie, pond and cultured lawn ecosystems Click on the image on the right to go more in-depth into the 3 different levels of biodiversity. Follow all the possible tabs as they become available because one of them relates to a Google Classroom question. This link may not open for some of you. I think you can answer the question, however, based on our class discussion and the reading below.
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The importance of biodiversity
Watch the 2 videos below to learn about and understand the interdependence of organisms and the importance of biodiversity. This should help you explain why it's so important to preserve biodiversity. For a more detailed explanation, go to the section below. Interdependence of organisms means how different species rely (or depend) on each other for their habitat needs (air, space, shelter, food, water.) In the interactive above, it shows how the bear relies on the fish, which relies on the crayfish for food. But these species depend on each other for other habitat resources as well. For example, a tree transpires (releases water vapor into the air through its leaves) and can affect the rainfall in the ecosystem, providing the pond with water for the bear, fish and crayfish.
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Why is biodiversity important and why should we protect it?
Why is biodiversity important?
First of all, make sure to watch the 2 videos above. They do a great job of explaining why biodiversity is so important. In our discussions, many of you have focused on the point that the losing a single species can cause an ecosystem collapse. But this isn't usually the case in a highly biodiverse ecosystem. Some species are very important to all the other species' survival, so this IS a possibility. BUT, if the ecosystem is highly biodiverse, this is less likely to happen because the loss of one species is not felt so strongly when other organisms can fill the needs of those organisms that depended on that lost species. High biodiversity helps keep an ecosystem in balance and more able to bounce back from (or be more resilient to) a species loss.
A example of this may be in our own Promega Woods. There is a great variety of bushes, trees and other plants in those woods that can provide food, shelter, air and water to a variety of organisms (species biodiversity). A squirrel, for example, may depend on: oak, cherry, black walnut and hickory trees for food (nuts and fruit), shelter (leaves and twigs to make nests in the branches, or tree cavities), water ( leaves, fruits and nuts contain water, but water can also collect on the leaves), and air (when the trees photosynthesize, one of the byproducts is oxygen, which is needed for respiration). There is a fungal disease called oak wilt. If it infects the oaks in the woods, the oak trees may all die out. If they do, the squirrel has other trees it can depend on for its habitat resources. But, since there is also genetic biodiversity (just like you, no two oaks are exactly alike) within the species of oak, maybe one or two of the oak trees have greater resistance to oak wilt and may not die out. The gene for resistance will be passed on to the oak's progeny (the new baby trees), and the population of oak can increase again. Either way, the squirrels may not feel the effects of the loss of oak trees very strongly because they are "generalists" (organisms that consume a variety of foods) and can rely on the variety of other species for their habitat resources. So, species and genetic biodiversity helps to make the woods more stable and resilient to change.
A species such as the Monarch, however, will not fare very well should the milkweed die out. Monarch caterpillars are "specialists" and rely exclusively on the 2-3 species of milkweed in our area for their food. By far, the common milkweed is most abundant species of milkweed in our area, so if it were to die out, the Monarch population would drop dramatically, if not die out completely.
Also, if that one lost species is a keystone species (a species whose role in the ecosystem is critical (or essential) for holding an ecosystem together and maintaining its balance), the ecosystem will face a greater threat of collapse. An example explained in one of the above videos is the acidification of oceans due to air pollutants that dissolve into the water. Corals (an animal) are particularly sensitive to increased acidity. Coral provide habitat for 25% of the all the ocean's animals, even though coral reefs occupy less than a percent of the entire ocean. Loss of corals causes the entire coral reef ecosystem to collapse. In the second video, they show how losing the "google" hub has far-reaching consequences, but losing MaggiesScienceConnection, for example, is problematic for my class, but there are other resources from which to learn the same material.
We watched a Nature program called "Serengeti Rules" that discusses how scientists discovered the importance of keystone species. Often, the keystone species is a predator such as the wolf or a bass, which keep the herbivores from consuming all the plants and destroying the ecosystem. But, sometimes it is an herbivore, as is the case for the wildebeest on the Serengeti plains. By keeping the grasses short as they graze, there are fewer wildfires on the plain. This allows trees to survive and grow, which then create more habitat and increase species biodiversity. As is the case of the starfish, it doesn't even have to be a top predator, since the starfish is predated on by larger animals. The starfish consumes mussels, which, if left unchecked, would take over the available space in the tidepool ecosystem and crowd out the other organisms. These are explained in the video.
Also, read this National Geographic article on keystone species.www.nationalgeographic.org/encyclopedia/keystone-species/ The importance of a keystone species is that it helps hold the ecosystem together and increases biodiversity, which, in turn increases the stability of the ecosystem.
Even if an ecosystem is highly biodiverse - like the coral reef system or the rainforest - ecosystem collapse CAN happen if major global changes such as climate change affect a large number of species in the ecosystem at the same time. This collection of organisms would not have the adaptations (or enough genetic biodiversity) to cope with that great an environmental change. Imagine if the rainforest climate became extremely cold as the world entered a new polar ice age! This can cause a mass extinction where large numbers of species that are not adapted to the cold would go extinct within a short period of time. An elephant isn't going to suddenly grow a wooly coat like it's ancestor, the wooly mammoth! Right now, the climate is warming because of increased greenhouse gases being put into the air by man's activities. There is scientific evidence that this is causing another mass extinction on our planet. There is evidence of several mass extinctions in the Earth's history, most of which scientists find have been caused by climate change. The most recent mass extinction was 65 million years ago when a large meteorite impact near Mexico changed the climate around the world and killed off about 75% of all species, including almost all the dinosaur species.
On a more local level, a major change can occur by cutting down a forest, or applying herbicides (plant poison) and pesticides (insect poison) to a field so a farmer can plant a single crop (called monoculture). Monocultures don't exist normally in nature because they are not stable or resilient to change. If a farmer were to stop tending a field, you'll quickly see other organisms start to populate the field - first "weeds," then bushes and trees and all the other organisms that interact with and depend on each other.
Even still, a few species might have the right adaptations to survive the new conditions, or their may be enough genetic variation in a single species that one of the variants my survive. They will repopulate the habitats and undergo further normal mutations (genetic variation). Some of those mutations provide advantages in the new habitat, allowing them to survive, and others do not, causing them to die. New species then evolve over time from these variations. This is how mammals, including humans, and the great variety of birds came to be after the mass extinction of the dinosaurs. Evidence supports that this extinction was caused by a large meteor that struck the earth (and there is some argument that there was simultaneously a greater amount of volcanic activity). Either way, this caused significant and dramatic climate change. There were only a few small mammal species that survived, and from those species evolved all the mammals we have today! Humans would not have existed had it not been for the last catastrophic mass extinction!
In summary, high biodiversity is important (a good thing!) because the more biodiverse the ecosystem (which includes both greater genetic variation within a single species and the greater numbers of species within an ecosystem), the more stable the ecosystem is and the more resilient (able to withstand or recover quickly from difficult conditions) it is to disruptions and change.
Why should we protect biodiversity?
Humans are a part of (not apart from) the ecosystems in which they live. Humans are among the few organisms that have the adaptation (our highly creative brain) that enables them to survive and reproduce in many of the world's different ecosystems. As part of those ecosystems, we contribute to, influence and change them by our activities, just like all the other species in that ecosystem. Think of all the pollinators that influence the reproduction of plants or the decomposers that make space or recycle nutrients to the soil and then back to the plants. Because there are such large numbers of humans living in a variety of ecosystems, our activities can be even more influential than other species. (Think of what New York City or Chicago would look like if humans didn't live there!) Humans activities can even change ecosystems in which they don't live (ex. coral reefs) by affecting the amount of harmful gases such as carbon dioxide or other air pollutants that dissolve into the warm reef waters.
Humans depend on other species for ALL of their habitat resources - oxygen from plants, food from plants and all the animals we eat that depend on plants as the basis for their food chain (or animals we depend on for pollinating the plants), shelter from plants, water that is purified by plants or provided in the plants we eat, and decomposers that provide space by removing dead organisms and nutrients that are recycled back to plants. We also rely on organisms for our medicines, our art and simply to make us feel good. Who doesn't feel better when they spend time in nature? If major changes occur in an ecosystem that cause significant reduction in biodiversity, we are just as likely to suffer as the other species in that ecosystem.
In summary, humans should protect biodiversity to keep ecosystems operating at their best so we and the organisms that depend on each other can survive and thrive.
First of all, make sure to watch the 2 videos above. They do a great job of explaining why biodiversity is so important. In our discussions, many of you have focused on the point that the losing a single species can cause an ecosystem collapse. But this isn't usually the case in a highly biodiverse ecosystem. Some species are very important to all the other species' survival, so this IS a possibility. BUT, if the ecosystem is highly biodiverse, this is less likely to happen because the loss of one species is not felt so strongly when other organisms can fill the needs of those organisms that depended on that lost species. High biodiversity helps keep an ecosystem in balance and more able to bounce back from (or be more resilient to) a species loss.
A example of this may be in our own Promega Woods. There is a great variety of bushes, trees and other plants in those woods that can provide food, shelter, air and water to a variety of organisms (species biodiversity). A squirrel, for example, may depend on: oak, cherry, black walnut and hickory trees for food (nuts and fruit), shelter (leaves and twigs to make nests in the branches, or tree cavities), water ( leaves, fruits and nuts contain water, but water can also collect on the leaves), and air (when the trees photosynthesize, one of the byproducts is oxygen, which is needed for respiration). There is a fungal disease called oak wilt. If it infects the oaks in the woods, the oak trees may all die out. If they do, the squirrel has other trees it can depend on for its habitat resources. But, since there is also genetic biodiversity (just like you, no two oaks are exactly alike) within the species of oak, maybe one or two of the oak trees have greater resistance to oak wilt and may not die out. The gene for resistance will be passed on to the oak's progeny (the new baby trees), and the population of oak can increase again. Either way, the squirrels may not feel the effects of the loss of oak trees very strongly because they are "generalists" (organisms that consume a variety of foods) and can rely on the variety of other species for their habitat resources. So, species and genetic biodiversity helps to make the woods more stable and resilient to change.
A species such as the Monarch, however, will not fare very well should the milkweed die out. Monarch caterpillars are "specialists" and rely exclusively on the 2-3 species of milkweed in our area for their food. By far, the common milkweed is most abundant species of milkweed in our area, so if it were to die out, the Monarch population would drop dramatically, if not die out completely.
Also, if that one lost species is a keystone species (a species whose role in the ecosystem is critical (or essential) for holding an ecosystem together and maintaining its balance), the ecosystem will face a greater threat of collapse. An example explained in one of the above videos is the acidification of oceans due to air pollutants that dissolve into the water. Corals (an animal) are particularly sensitive to increased acidity. Coral provide habitat for 25% of the all the ocean's animals, even though coral reefs occupy less than a percent of the entire ocean. Loss of corals causes the entire coral reef ecosystem to collapse. In the second video, they show how losing the "google" hub has far-reaching consequences, but losing MaggiesScienceConnection, for example, is problematic for my class, but there are other resources from which to learn the same material.
We watched a Nature program called "Serengeti Rules" that discusses how scientists discovered the importance of keystone species. Often, the keystone species is a predator such as the wolf or a bass, which keep the herbivores from consuming all the plants and destroying the ecosystem. But, sometimes it is an herbivore, as is the case for the wildebeest on the Serengeti plains. By keeping the grasses short as they graze, there are fewer wildfires on the plain. This allows trees to survive and grow, which then create more habitat and increase species biodiversity. As is the case of the starfish, it doesn't even have to be a top predator, since the starfish is predated on by larger animals. The starfish consumes mussels, which, if left unchecked, would take over the available space in the tidepool ecosystem and crowd out the other organisms. These are explained in the video.
Also, read this National Geographic article on keystone species.www.nationalgeographic.org/encyclopedia/keystone-species/ The importance of a keystone species is that it helps hold the ecosystem together and increases biodiversity, which, in turn increases the stability of the ecosystem.
Even if an ecosystem is highly biodiverse - like the coral reef system or the rainforest - ecosystem collapse CAN happen if major global changes such as climate change affect a large number of species in the ecosystem at the same time. This collection of organisms would not have the adaptations (or enough genetic biodiversity) to cope with that great an environmental change. Imagine if the rainforest climate became extremely cold as the world entered a new polar ice age! This can cause a mass extinction where large numbers of species that are not adapted to the cold would go extinct within a short period of time. An elephant isn't going to suddenly grow a wooly coat like it's ancestor, the wooly mammoth! Right now, the climate is warming because of increased greenhouse gases being put into the air by man's activities. There is scientific evidence that this is causing another mass extinction on our planet. There is evidence of several mass extinctions in the Earth's history, most of which scientists find have been caused by climate change. The most recent mass extinction was 65 million years ago when a large meteorite impact near Mexico changed the climate around the world and killed off about 75% of all species, including almost all the dinosaur species.
On a more local level, a major change can occur by cutting down a forest, or applying herbicides (plant poison) and pesticides (insect poison) to a field so a farmer can plant a single crop (called monoculture). Monocultures don't exist normally in nature because they are not stable or resilient to change. If a farmer were to stop tending a field, you'll quickly see other organisms start to populate the field - first "weeds," then bushes and trees and all the other organisms that interact with and depend on each other.
Even still, a few species might have the right adaptations to survive the new conditions, or their may be enough genetic variation in a single species that one of the variants my survive. They will repopulate the habitats and undergo further normal mutations (genetic variation). Some of those mutations provide advantages in the new habitat, allowing them to survive, and others do not, causing them to die. New species then evolve over time from these variations. This is how mammals, including humans, and the great variety of birds came to be after the mass extinction of the dinosaurs. Evidence supports that this extinction was caused by a large meteor that struck the earth (and there is some argument that there was simultaneously a greater amount of volcanic activity). Either way, this caused significant and dramatic climate change. There were only a few small mammal species that survived, and from those species evolved all the mammals we have today! Humans would not have existed had it not been for the last catastrophic mass extinction!
In summary, high biodiversity is important (a good thing!) because the more biodiverse the ecosystem (which includes both greater genetic variation within a single species and the greater numbers of species within an ecosystem), the more stable the ecosystem is and the more resilient (able to withstand or recover quickly from difficult conditions) it is to disruptions and change.
Why should we protect biodiversity?
Humans are a part of (not apart from) the ecosystems in which they live. Humans are among the few organisms that have the adaptation (our highly creative brain) that enables them to survive and reproduce in many of the world's different ecosystems. As part of those ecosystems, we contribute to, influence and change them by our activities, just like all the other species in that ecosystem. Think of all the pollinators that influence the reproduction of plants or the decomposers that make space or recycle nutrients to the soil and then back to the plants. Because there are such large numbers of humans living in a variety of ecosystems, our activities can be even more influential than other species. (Think of what New York City or Chicago would look like if humans didn't live there!) Humans activities can even change ecosystems in which they don't live (ex. coral reefs) by affecting the amount of harmful gases such as carbon dioxide or other air pollutants that dissolve into the warm reef waters.
Humans depend on other species for ALL of their habitat resources - oxygen from plants, food from plants and all the animals we eat that depend on plants as the basis for their food chain (or animals we depend on for pollinating the plants), shelter from plants, water that is purified by plants or provided in the plants we eat, and decomposers that provide space by removing dead organisms and nutrients that are recycled back to plants. We also rely on organisms for our medicines, our art and simply to make us feel good. Who doesn't feel better when they spend time in nature? If major changes occur in an ecosystem that cause significant reduction in biodiversity, we are just as likely to suffer as the other species in that ecosystem.
In summary, humans should protect biodiversity to keep ecosystems operating at their best so we and the organisms that depend on each other can survive and thrive.
What causes loss of species biodiversity?
Species biodiversity loss (the reduction in the number of different species) can be caused by both natural and human-caused events. A natural cause might be a wildfire destroying a forest, a new disease that affects a particular organism, a volcano erupting or even a meteorite hitting the earth. Extinction is a normal part of life on earth. Some species die out simply because they may no longer have the right adaptations to survive in their habitat as it changes. An example may be a new disease such as the oak wilt disease that kills oak trees. A mass extinction, however, occurs when a large number of species go extinct over a very short period of time due to big changes in the planet - particularly climate change. Mass extinctions have occurred a few times in the last 3.5 billion years.The most recent mass extinction occurred when a meteorite hit the earth 65 million years ago and the circulating dust around the planet caused the average temperatures to drop. Many of the plants and the large dinosaurs were not adapted to live in cooler temperatures and went extinct.
Evidence now shows that the ever-increasing human population is causing great losses of species to the point where the Earth is experiencing another mass extinction. One reason is because a growing population of humans is using more and more space and destroying habitat. Habitat loss is caused by a variety of things, such as construction (building homes, highways and other construction), deforestation (removing forests) for wood or clearing land for crops for raising meat or dairy animals, and mining for minerals that we use for a great variety of things. Humans are also using more and more more habitat resources which takes them away from other organisms. And humans are polluting water and air, which has global effects. For example, air pollution is causing global warming and a significant change in climate, which can then cause organisms that are not adapted to these conditions to go extinct. Global warming does this by changing or destroying habitats by increasing wildfires and severe weather events (flooding, hurricanes, drought) as well as melting glaciers and the polar ice caps. Increases in sea level will cause coastal lands and some islands to become submerged underwater. It also changes the convection currents in the ocean (such as the Gulf Stream), which affects climate in the northern regions of the planet. Air pollution is also changing the acid levels in the ocean water, which affects coral reefs.
Please read this article from the National Wildlife Federation. Not only does it explain biodiversity, but it talks about it's importance, what threatens it and what you could do. One of the most important things you can do is reduce your consumption, reuse and recycle materials and, above all - don't waste resources! The more you know, the more you can make a difference!
Evidence now shows that the ever-increasing human population is causing great losses of species to the point where the Earth is experiencing another mass extinction. One reason is because a growing population of humans is using more and more space and destroying habitat. Habitat loss is caused by a variety of things, such as construction (building homes, highways and other construction), deforestation (removing forests) for wood or clearing land for crops for raising meat or dairy animals, and mining for minerals that we use for a great variety of things. Humans are also using more and more more habitat resources which takes them away from other organisms. And humans are polluting water and air, which has global effects. For example, air pollution is causing global warming and a significant change in climate, which can then cause organisms that are not adapted to these conditions to go extinct. Global warming does this by changing or destroying habitats by increasing wildfires and severe weather events (flooding, hurricanes, drought) as well as melting glaciers and the polar ice caps. Increases in sea level will cause coastal lands and some islands to become submerged underwater. It also changes the convection currents in the ocean (such as the Gulf Stream), which affects climate in the northern regions of the planet. Air pollution is also changing the acid levels in the ocean water, which affects coral reefs.
Please read this article from the National Wildlife Federation. Not only does it explain biodiversity, but it talks about it's importance, what threatens it and what you could do. One of the most important things you can do is reduce your consumption, reuse and recycle materials and, above all - don't waste resources! The more you know, the more you can make a difference!
This Bill Nye video on Biodiversity is optional. Make sure you do your other homework before watching this!
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Where do our Fossil Fuels Come From?
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I love how these videos explain where we get the energy we use and why fossil fuels are causing climate change. Climate change is a big threat to biodiversity.
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