About this video
Using Joshua Tree National Park as an example, the video explains that organisms need resources from biotic (living) and abiotic (non-living) factors to survive. The combination of these factors decides which organisms can live in a place, and because the factors are limited, organisms often compete for them.
You'll be able to
- define biotic and abiotic factors and give examples of each.
- explain how biotic and abiotic factors together decide which organisms live in a place.
- describe how organisms compete for limited biotic and abiotic factors.
Key words
- biotic factor
- A living part of an environment, such as plants, animals, fungi or bacteria.
- abiotic factor
- A non-living part of an environment, such as air, sunlight, water or temperature.
- resource
- Something an organism needs from its environment to survive.
- competition
- When organisms need the same limited resource, like water or shade.
Transcript
- [Presenter] This is Joshua Tree National Park, and it is a true desert climate. What does that mean? Well, for one, it means it gets very little rain over here, only about 4 to 5 inches in an entire year. And the air is extremely dry, which causes the land to heat up very quickly during the day and cool down very quickly at night.
So the daily temperatures can sometimes differ by about 50 degrees Fahrenheit or even more. And yet, some organisms live here just fine. For example, Joshua trees grow tall in the desert. We have kangaroo rats that survive without ever drinking liquid waters. And chuckwalla lizards can rest just fine on sun-warmed rocks.
But many organisms couldn't survive here at all. So, that begs the question, why can some organisms live in a particular place while others can't? The answer has to do with the conditions and resources available in the environment. Okay, what do I mean by that?
Every living thing from the largest plants and animals to the smallest microorganisms, need certain things, certain resources to survive, right? Now, those resources can come from the living parts of the environment, which we call the biotic factors, and the non-living parts of the environment, which we call the abiotic factors.
It's the combination of these biotic and abiotic factors that decide which organisms can live in a particular environment, and which can't. So let's talk about this in more detail. What are biotic factors? The biotic factors represent the living components of an environment necessary for survival of an organism, which means this includes all the living beings.
I'm talking about plants, animals, fungi, and even microorganisms like bacteria. And what are abiotic factors? They represent the non-living components of an environment necessary for an organism's survival. So think about air, sunlight, water, temperature, and so much more.
Let's take a couple of examples. Plants, for example, need sunlight and water in order to grow, right? These are abiotic factors. But many plants also depend on living organisms such as insects, to pollinate them, so these are biotic factors. Another example. Deer depends on grass for food, biotic factors, but it also depends on safe temperature ranges and access to water, for example, abiotic factors.
So together, the biotic and the abiotic factors explain why organisms live where they do and why they don't live elsewhere. So coming back to Joshua Tree National Park, what are some biotic factors over here? Well, think about this, grasshoppers and chuckwalla lizards, for example, depend on the bushes and the desert flowers that are available, so that's a biotic factor.
Kangaroo rats eat the seeds that are available over here, that's another biotic factor. Tarantulas feed on the grasshoppers, so they are also the biotic factors. So like I said, all the living things that you can think of are the biotic factors. They're necessary for the survival of other living things that live over here.
Okay, what are some abiotic factors over here? Well, they represent very limited rainfall, the extreme temperatures, the rocky and sandy soil that you find over here, and very intense sunlight. So the very specific combination of biotic in abiotic factors that you find over here, decides which organisms survive over here and which don't.
If either type of factor is missing or changes too much, survival becomes difficult or even impossible. And what's also important is that these biotic and abiotic factors are limited, so organisms can often compete for them. For example, in dry environments, plants may compete for water in the soil, and animals may compete for shade or for burrows that protect them from extreme heat during the day.
So to summarize, organisms require a combination of the biotic and the abiotic factors to survive in an environment. The biotic factors include all the living components, plants, animals, fungi, and microorganisms. And the abiotic factors will include all the non-living components.
And there are plenty of non-living components that are available here. Here are some of these examples. Survival always depends on a combination of both.
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