Natural Ecosystem Change

Summary

In this environmental science video, Mr. Andersen explores natural ecosystem changes, emphasizing the impact of climate on species and land. He discusses how ice core data from Antarctica reveals carbon dioxide levels and temperature fluctuations over 450,000 years, correlating with ice ages and desert expansions. Factors influencing climate include the Earth's position relative to the sun, solar output variations, and geological activities like volcanism and plate tectonics. These changes can lead to mass extinctions and adaptive radiation, with species adapting or going extinct. The video also covers primary and secondary succession, illustrating how life reclaims barren areas over time.

Takeaways

• 🧊 Ice cores from Antarctica's Vostok station provide a historical record of atmospheric carbon dioxide levels and temperature changes over 450,000 years.
• 🌡️ Climate changes, including ice ages, are associated with high dust concentrations in ice cores, indicating extensive deserts and increased wind activity.
• 🌍 Earth's climate is influenced by its position relative to the sun, changes in solar output, and factors like orbit variations, volcanic activity, and plate tectonics.
• 🌑 Ice ages are characterized by extensive ice coverage, affecting regions like Canada, Great Britain, Scandinavia, and parts of the US.
• 🌋 Volcanic eruptions, such as Mount Pinatubo in 1991, can release sulfur dioxide into the atmosphere, leading to a temporary cooling effect on the planet.
• 🌎 Plate tectonics, like the formation of the Isthmus of Panama, can alter ocean currents and significantly impact global climate patterns.
• 🦕 Mass extinctions, driven by events like asteroid impacts, have led to significant losses in biodiversity, followed by adaptive radiation where new species emerge.
• 🐾 As climate changes, species like polar bears are forced to adapt by moving into new areas and exploiting different ecological niches.
• 🌲 The distribution of plant species, such as birch, spruce, and pine, has shifted significantly over the last 21,000 years in response to retreating ice.
• 🌱 Succession, both primary and secondary, allows life to return to areas after significant changes, such as volcanic activity or forest fires, through a gradual process of colonization and ecosystem rebuilding.

Q & A

What is the significance of ice cores collected at Vostok station in Antarctica?

Ice cores collected at Vostok station in Antarctica are significant because they contain ancient atmospheres. By melting them in a lab, researchers can analyze how carbon dioxide levels have changed over the last 450,000 years, which corresponds with temperature changes.

How do ice ages correlate with dust concentrations in ice cores?

Ice ages correspond with high dust concentrations in ice cores because during these periods, massive deserts form on the planet. Increased wind activity traps sediment, which gets preserved in the glaciers.

What factors affect the Earth's climate according to the video?

The Earth's climate is affected by the Earth's position relative to the sun, changes in solar output, slight changes in Earth's orbit, volcanic activities, and plate tectonics.

What is the role of solar output in climate change?

Solar output plays a role in climate change by affecting the amount of energy Earth receives from the sun. Changes in the sun's output over thousands of years can lead to variations in climate.

How do volcanic eruptions impact the Earth's climate?

Volcanic eruptions, such as the 1991 Mount Pinatubo eruption, can increase the amount of sulfur dioxide in the atmosphere, which cools the planet. This can lead to a temporary cooling effect on the Earth's climate.

What is the difference between primary and secondary succession?

Primary succession occurs on bare rock where no soil or community exists, while secondary succession takes place where the soil and community remain after a disturbance, allowing for a faster recovery of the ecosystem.

How does the distribution of species change during climate shifts?

The distribution of species changes as they move into new areas and exploit new niches in response to climate shifts. This can be observed in the changing habitat of polar bears and the distribution of certain tree species over the last 21,000 years.

What is the significance of the asteroid impact mentioned in the video?

The asteroid impact mentioned in the video led to a mass extinction event, which in turn resulted in an adaptive radiation of mammals, illustrating the drastic effects climate change can have on species and ecosystems.

How does the video explain the process of succession after an environmental disturbance?

The video explains that succession is a process where life gradually returns to an area after a disturbance. It begins with weathering and the introduction of pioneer species, followed by grasses, forbes, bushes, and eventually larger trees, taking hundreds to thousands of years.

What is the potential impact of climate change on polar bears as discussed in the video?

The video suggests that climate change, particularly the melting of polar ice, could impact polar bears by reducing their habitat. If they do not go extinct, they may move into new areas and exploit new niches to survive.

Outlines

00:00

🌐 Climate Change and Ecosystems

This paragraph discusses the impact of natural ecosystem changes on climate and species. Researchers use ice cores from Antarctica to study historical carbon dioxide levels and their correlation with temperature changes. Ice ages are linked to high dust concentrations, indicating extensive deserts and increased wind activity. The Earth's position relative to the sun, changes in solar output, and geological factors like volcanic activity and plate tectonics all influence climate. These factors can lead to mass extinctions and adaptive radiation, where new species emerge. The paragraph also touches on the concept of species migration in response to climate shifts and the role of abiotic factors in shaping ecosystems. It concludes by emphasizing the significance of the Earth's position to the sun and the sun's variability in affecting climate and ecosystems.

05:03

🌿 Succession and Ecosystem Recovery

The second paragraph delves into the process of ecological succession, which is the gradual process of ecosystem recovery after a disturbance. It explains primary succession, where life colonizes an area from bare rock, and secondary succession, where life reestablishes itself in an area where the soil and community structure remain. The paragraph illustrates these concepts with examples, such as a lava flow and a forest recovering from a fire. It highlights the resilience of ecosystems and the natural mechanisms that allow them to rebuild and adapt over time, even after significant disruptions like mass extinctions. The paragraph concludes by reinforcing the interconnectedness of climate, ecosystems, and the processes that drive their evolution.

Keywords

💡Ice Cores

Ice cores are cylindrical samples of ice extracted from glaciers or ice sheets. They are valuable for studying past climates because they contain trapped air bubbles that can be analyzed to determine the composition of the atmosphere at the time the ice formed. In the video, researchers use ice cores collected from Vostok station in Antarctica to study how carbon dioxide levels have changed over the last 450,000 years, which is directly related to understanding climate change.

💡Carbon Dioxide

Carbon dioxide (CO2) is a greenhouse gas that plays a significant role in the Earth's climate system by trapping heat in the atmosphere. The video discusses how levels of carbon dioxide have fluctuated over time, corresponding with temperature changes, and how these fluctuations can be observed in ice cores. This is crucial for understanding the natural and human-induced changes in climate.

💡Ice Ages

Ice ages are periods in Earth's history when large areas of the planet are covered by ice sheets. The video mentions that ice ages correspond with high dust concentrations in ice cores, indicating colder periods. These periods are significant for understanding the natural variability of Earth's climate and how ecosystems have responded to such changes.

💡Solar Output

Solar output refers to the amount of energy emitted by the Sun, which is a critical factor in determining Earth's climate. The video explains how changes in solar output, such as variations in sunspot activity and long-term changes in the Sun's energy output, can affect the climate. This concept is essential for understanding the external forces that influence climate change.

💡Orbit

The Earth's orbit around the Sun is another factor that influences climate. The video discusses how slight changes in Earth's orbit can lead to climate variations. This includes concepts like precession, which is the slow wobble of Earth's axis, affecting the amount of sunlight received at different latitudes over thousands of years.

💡Volcanism

Volcanism refers to the geological process of volcanic activity, which can release gases and particles into the atmosphere, affecting climate. The video uses the example of Mount Pinatubo's eruption in 1991, which increased sulfur dioxide levels and cooled the planet, illustrating the impact of volcanic events on climate.

💡Plate Tectonics

Plate tectonics is the movement of Earth's lithosphere, which can lead to the formation or destruction of landmasses and affect climate patterns. The video gives an example of how the formation of the Isthmus of Panama changed ocean currents and influenced climate, demonstrating how geological changes can have significant climatic effects.

💡Mass Extinctions

Mass extinctions are events where a large number of species become extinct in a relatively short geological time. The video discusses how climate changes, such as those caused by volcanic eruptions or asteroid impacts, can lead to mass extinctions, which are critical moments in Earth's history that reshape ecosystems and the evolution of life.

💡Adaptive Radiation

Adaptive radiation is the rapid diversification of species into new forms and ecological niches following a mass extinction or other significant environmental change. The video explains how adaptive radiation can lead to the emergence of new species, as seen after past mass extinctions, highlighting the resilience and adaptability of life on Earth.

💡Succession

Succession is the process by which ecosystems change over time following a disturbance. The video describes two types of succession: primary, where the soil and community are completely gone, and secondary, where the soil and some community members remain. Succession illustrates the dynamic nature of ecosystems and their ability to recover after disturbances.

💡Polar Bears

Polar bears are used in the video as an example of species that are affected by climate change, particularly the melting of Arctic ice. The video discusses how polar bears may need to adapt to new habitats as their traditional range shrinks, highlighting the direct impact of climate change on wildlife and the need for species to adapt to changing conditions.

Highlights

Researchers at Vostok station in Antarctica collect ice cores to study ancient atmosphere.

Carbon dioxide levels and temperature changes are correlated over the last 450,000 years.

Ice ages correspond with high dust concentrations due to increased wind and desertification.

Changes in the Earth's relation to the sun affect climate and ecosystems.

Solar output variations, including sunspot cycles, influence climate.

Precession of the Earth's spin and orbit alters climate patterns over millennia.

Volcanic eruptions, like Mount Pinatubo in 1991, can cool the planet temporarily.

Plate tectonics, such as the formation of the Panama isthmus, affect ocean currents and climate.

Historical mass extinctions have been followed by adaptive radiation of new species.

Climate change impacts species distribution, such as polar bears' habitat.

Plants and animals respond to climate change by migrating to new areas and exploiting new niches.

Succession, both primary and secondary, is the process of life returning to changed or destroyed land.

Primary succession occurs on bare rock, while secondary succession happens where soil and seeds remain.

The video discusses the potential for a sixth mass extinction due to current climate changes.

Adaptive radiation allows for the emergence of new species following mass extinctions.

The video concludes by summarizing the impacts of climate change on ecosystems and the processes of succession.

Transcripts

Hi. It’s Mr. Andersen and this environmental science video 10. It is on natural ecosystem

change. In this picture these researchers are holding ice cores that they collected

at Vostok station in Antartica. We can take those ice cores, melt them in the lab and

it releases this ancient atmosphere. So we could look at, for example, how carbon dioxide

levels have changed over the last 450,000 years. Now that corresponds with temperature

changes. So we have had periods of time where it is warmer and what are called ice ages

where it is much colder. Now the ice ages actually correspond with high dust concentrations

in the ice core because during ice ages we also have these massive deserts on our planet.

Wind increases and that sediment is trapped in the glaciers. And so the climate has changed

and that has affected ecosystems on our planet. But what is affecting the climate? It is where

the earth is in relation to the sun. And so as we have had changes in solar output that

has affected our climate. As we have had slight changes in our orbit or volcanoes or plate

tectonics, all of those things have affected our climate and therefore are affecting the

ecosystems. Not only the life but also the land. At the worst level it can cause what

are called mass extinctions on our planet where a number of species simply go away.

Lots of times that is followed by adaptive radiation where different species come back.

But for the most part what happens is species have to respond. So species will move back

and forth as the climate changes. Now it also affects the abiotic factors. So the land on

our planet. And so what happens after the land is destroyed or changed is we have succession

as life moves back into that area. It can be either primary or secondary. In primary

succession the soil and the community is gone. In secondary the soil and the community actually

remain. And so what is affecting our climate? It is where the earth is in relation to the

sun. And scientists have noted that the sun changes over time. So we have these sun spot,

eleven year sun spot cycles. But we have these larger changes in the output of the sun over

thousands of years. We also find precession in the earth. As it spins it also starts to

wobble over thousands of years. And that causes changes in our climate. The pole starts to

point in different directions so we get varying amounts of light. And then we are also finding

that there is precession in the orbit itself. As it moves around over thousands of years

we have changes in the amount of energy that we are getting from the sun. So all of these

correspond to changes in energy from the sun. So if we look at how these models match up

with the data that we are collecting in ice cores we can see this cycling of our climate

over time. We are going to have these ice ages. And if we look down at the northern

hemisphere this is what it would be like during the worst ice age. That whole area that is

gray would be covered in ices. That means most of Canada, Great Britain, all of Scandinavia

would be covered. It would move down into the US as well. Massive ice sheets. And then

we would have times where there is not much ice at all. Just this dark area where Greenland

is and then along the coast right here. Another things that can affect climate is going to

be volcanoes. And so for example in 1991, in the Philippines Mount Pinatubo exploded.

That increases the amount of sulfur dioxide in the atmosphere and it cools the planet

so the planet cooled over the next three years just due to this one eruption. And then we

can have plate tectonics that are affecting the amount of energy that we get as well.

So a simple example, South America slid into North America and Panama was formed. What

happened? There used to be a current that moved through here and that changed the whole

current. And so that is going to affect the climate. Or at the largest level Pangea was

all of the continents coming together. We had massive deserts forming in the middle.

And that is going to change species on our planet. It lead to some of the worst mass

extinctions on our planet. Where a large percent of life actually went away. Now this changed

eventually as they broke apart, we had an adaptive radiation and all of these dinosaur

species showed up. What happened to them? We had a giant asteroid impact. Mass extinction.

And that led to adaptive radiation of the mammals. And some people are saying we are

headed into a sixth mass extinction. And so this is the worst way that climate can affect

species. Now as the climate changes animals can move. And so polar bears are going to

be impacted. This is a distribution of prime polar bear habitat. And you can see it is

being impacted all the way around the pole. Now if polar bears do not go extinct, what

are they going to do? They are going to move into new areas. And they are going to exploit

new niches. Plants will do the same thing. And so as the planet has gotten warmer and

warmer and warmer, this is a distribution of prairie birch, spruce and pine trees over

the last 21,000 years. And so watch what happens to their distribution. So now we are looking

at 12,000 years ago. And now 6,000 years ago. And now present day distribution. So you can

see that as the ice retreated the plants moved into that area. Now they are not like polar

bears. They cannot walk, and so this is a slow transition. But the movement of seeds,

the movement of pollen moves them into that area. Now as the ice moves away what is left?

It is just going to be bare rock. And so how do we go from bare rock to life? That process

is called succession. An so what happens, we have some weathering. We have some pioneer

species that start to move in. And then we have some grasses. Then we start to have some

forbes and some bushes move in. You can see the soil is starting to increase. Then we

have small trees. And then we have larger trees that start to move into that area. And

so it takes hundreds if not thousands of years for this to occur. But you can see it taking

place right here. This is a lava flow. And over time soil is going to start to form and

then life is going to move back into that area. This is primary succession because all

that is left is the rock. We can also have secondary succession. So this is a forest

one year after a forest fire came through. And so you can see that some of the life is

starting to come back. Let me show you what it looks like a year later. Way more of that

life has come back. And that is because the soil is still there and a lot of the seeds

are still there and it is a natural way that this forest can rebuild itself. And so did

you learn the following. Could you pause the video now and fill in the blanks? So again

climate is affected by the sun’s output, the orbit, volcanism and then plate tectonics.

That changes the ecosystems, both land and life. Extinctions, mass extinctions eventually

leads to adaptive radiation. And on the land we can have succession, either primary or

secondary. And I hope that was helpful.