Introduction to Terrestrial Biomes - Online Tutor, Practice Problems & Exam Prep

Terrestrial biomes are large land areas characterized by distinct climates, flora, and fauna. Each biome hosts unique ecosystems, with variations even among similar biomes globally. Disturbances, such as wildfires, can significantly alter these ecosystems, influencing species distribution and resource availability. Some biomes depend on regular disturbances to maintain ecological balance, preventing destructive events by managing fuel accumulation. Understanding these dynamics is crucial for grasping ecosystem resilience and biodiversity.

Introduction to Terrestrial Biomes

In this video, we're going to begin our introduction to terrestrial biomes. Now a biome can be defined as a large area on Earth with a distinctive climate, dominant plants that we call flora, and typical animals that we call fauna. Now, terrestrial biomes are those that are specifically found on land. And later in our course, we will shift our focus over to aquatic biomes, those found on water, but for now, we focus on terrestrial biomes. Terrestrial biomes are primarily characterized by their climate and by their vegetation.

Now, it's important to note that each of these biomes is going to host unique ecosystems, which means that the same biomes found across the globe on different continents are going to be very similar to each other, but they're not going to be perfectly identical to each other. And so, although that may seem obvious, it's important to point out. For example, if we take a look at our world map down below color-coded to the terrestrial biomes, notice that the ones in yellow here are deserts. And although deserts are found across the globe on different continents and all share similar characteristics, like low precipitation, they're not all perfectly identical to each other. So, for example, the desert in North Africa, the Sahara Desert, has camels in it, but the deserts in North America do not.

Now another important point is that the boundaries between each biome on this map look like they're very clear and distinct. However, in reality, the boundaries between neighboring biomes are going to slowly and gradually transition into each other, creating what's known as an ecotone. And so an ecotone is a transitional zone between two or more biomes, often with mixed characteristics between each of the neighboring biomes, making it extremely difficult to determine the boundaries of these biomes, which is why there are slightly different versions of maps like this with slightly different boundaries. Now moving forward in our course, we're going to talk about each of these terrestrial biomes in their own separate videos. So that concludes this introduction.

I'll see you in our next video.

Introduction to Terrestrial Biomes Example 1

So here we have a really straightforward example problem asking, which of the following is considered a biome? And we've got these 4 potential answer options down below. Now recall from our last lesson video that a biome is defined as a large area on earth with distinctive climate, dominant plants, and typical animals. And so after looking at these options, there's only one that is clearly a biome, and that's going to be option d, the desert. So we can indicate that d is the correct answer to this example.

Now option a says Miami Beach, but that does not meet the criteria for a biome. Option b says a giant sequoia tree. That's just an individual organism. Again, doesn't meet the criteria for a biome. And then option c says a public park, but once again, does not meet the criteria for a biome.

So do you hear us correct? And I'll see you all on our next video.

Which of the following statements is correct?

• A. All biomes can be found at high latitudes.
• B. All biomes can be found at tropical & subtropical latitudes.
• C. Each biome can be found on multiple different continents.
• D. Each biome is exclusive to one continent.

Disturbances Make Biomes Dynamic

In this video, we're going to talk about how disturbances make biomes dynamic. A disturbance can be defined as a relatively short-lived event that significantly changes or disrupts the structure and function of an ecosystem, often influencing resource availability and, therefore, also influencing species distribution, including the distribution of both plants and animals. This is because a disturbance can create new opportunities for species to disperse and spread. Now, down below the left-hand side, we have a list of some examples of disturbances that include things such as wildfires. Although it's true that a disturbance can be considered a bad thing for a community, it's not always necessarily considered a bad thing because some biomes actually have regular or predictable disturbances called a disturbance regime that the community actually depends on or relies on for its long-term survival.

As an example, let's take a look at these giant sequoia trees that can be found in California and rely on a regular disturbance regime, mainly regular wildfires. It's important to note that over time, branches, twigs, trees, pine needles, leaves can fall to the ground floor and serve as fuel for a wildfire. Initially, there will be a low amount of fuel, and with a regular disturbance regime, a low amount of fuel can only support a small fire. However, without a regular disturbance regime, the fuel on the ground floor will continuously build up, leading to an eventual large and destructive fire that can completely wipe out the community. With a regular disturbance regime, regular wildfires, the regular small fires can somewhat prevent fuel accumulation on the ground floor and, therefore, prevent larger, more destructive fires that can wipe out the community, allowing the community to survive long term.

So this here concludes our lesson on disturbances, and I'll see you all in our next video.

Introduction to Terrestrial Biomes Example 2

So here we have a pretty straightforward example problem that asks, which of the following would not be considered a disturbance to a community? And we've got these 4 potential answer options down below. Now, of course, we know from our last lesson video that a disturbance can be defined as a relatively short-lived event that significantly changes or disrupts the structure and function of an ecosystem. And we know from our last lesson video that some examples of disturbances include droughts, such as a prolonged drought, floods, including flash floods, and hurricanes as well. And so we can go ahead and eliminate those answer options because, again, we're looking for the option that is not considered a disturbance and all of these options, a, b, and d, are considered disturbances.

And so this leaves option c, which is the correct answer, a day with no rainfall. It turns out that there is no region on earth that gets continuous rainfall every single day of the year, even the regions on earth that have the most annual rainfall will get at least a few days with no rainfall at all, and so a day without rainfall is not going to have a significant change or a significant disruption to the structure and function of any particular community. So that is not considered a disturbance, and we can indicate that c here is the correct answer to this example. So I'll see you all in our next video.

Which of the following is least likely to be influenced by a single disturbance to an ecosystem?

• A. The amount of annual precipitation.
• B. The abundance/dispersal of vegetation.
• C. The abundance/dispersal of animals.
• D. Cleanliness of water.