Biotic and abiotic factors in Earth’s natural systems

0:00This right over here is a picture of Earth Not likely a surprise for most of y'all But what we're gonna talk about in this video and future video is how we can view Earth as a system Many of y'all might be familiar with the term, system We talk about systems as a bunch of things interacting together in very very complex ways Now the first-division that we could think about, the constituent pieces of the system we could think about what is living and what is not living and that's where the title of this video comes from biotic and abiotic factors Now, what do you think biotic means?

0:45And I'll give you a hint. It has the word bio in it, which refers to life Well, a biotic factor is a living factor So this is a living factor. Now, what's a living factor in a system For example, our bodies are a system. Our bodies are alive, but you also have biotic factors within that system.

1:10For example, you have gut bacteria inside of your intestines. That bacteria, they can live on their own if they needed to, but they are also part of your body's system. So the bacteria in your gut is a biotic factor. And some of you might be saying, "Hey, yeah, sometimes when I'm sick, my parents have given me antibiotics."

1:32And antibiotics are against living factors that are in your body. Now, antibiotics are usually if you have bad bacteria that are floating around in your blood or some other place that you wanna get rid of, but it can also affect your good biotic factors, say, the gut bacteria that you actually need to help with your digestion.

1:54So we now know that a biotic factor is a living factor. So what do you think abiotic means? Well, generally, when you have A in front of something, it means not, or the opposite of. So, an abiotic factor is a non-living factor. Now, if you're thinking about an abiotic factor inside of a system, it might be the soil around you.

2:21it might be the air pressure, the molecules. It might be the water pressure, the temperature, things that are actually not living. And you can imagine that these, in many systems, will interact with each other. So now we have the basics of living factors And non-living factors, biotic and abiotic, Let's start to break down Earth as a system into some of the highest level systems that people will describe it.

2:49And these tend to be described as spheres. Now, why spheres? Well, Earth itself is a sphere. And the four main spheres that Earth scientists, biologists, other scientists will talk about, are, in no particular order, the atmosphere, which is probably a term that you have heard of, and the atmo prefix is referring to all of the air around the Earth We have about a 60-mile-thick layer of atmosphere.

3:22Now, 60 miles sounds thick to us, but it's a very thin layer if you think about it from Earth's point of view. You can barely see the little thin atmospheric layer in this image of Earth that I got from NASA. But the atmosphere is all the gases that surround the Earth.

3:41And why is it a sphere? If you don't consider all of the water, all of the land, all of the living organisms, but Earth were to somehow maintain its shape, well, then that air, all of the gases around the Earth would still be a sphere. What other spheres are there?

3:56Well, there's the biosphere, which you can imagine is all of the living organisms on Earth. So once again, remove all the gas, or don't consider the gas, the land and the water But if all of the living organisms stayed in place where they are, and we're talking about trillions and trillions of organisms all over Earth, they are for the most part at the surface or very close to the surface of Earth, it would still resemble a sphere.

4:21And then another sphere that we could consider is all of the water. Not only on the surface of the Earth, but also below the surface of the Earth, the hydrosphere. So when you look at this picture, it's obvious that the oceans and seas are the part of that, but also lakes and rivers, and actually any form of water.

4:41We could even be talking about precipitation. We could be talking about rain. We could be talking about icebergs because that, too, is water. And then the last sphere, which would really make up the bulk of the mass of Earth, all of the interior and surface of the Earth, including the rocks, the continents, and the oceans floor, well, then you are talking about the geosphere All of the non-water, non-gas, non-living things that make up Earth, which is really most of Earth.