Terrestrial Biomes: Near Equator - Online Tutor, Practice Problems & Exam Prep

Tropical rainforests, located near the equator, boast high biodiversity, housing over 50% of the world's species. They experience consistent high temperatures and significant rainfall, fostering dense vegetation with vertical layering that creates diverse habitats. In contrast, savannahs, or tropical grasslands, feature scattered trees and a long dry season, leading to frequent wildfires that shape the ecosystem. Deserts, characterized by low precipitation and variable temperatures, require plants and animals to adapt for water conservation. Understanding these biomes is crucial for grasping ecological dynamics and biodiversity conservation.

Tropical Rainforests

This video, we're going to cover the very first terrestrial biome in our lesson, which are the tropical rainforests. Now to orient you a bit with what you can expect to see moving forward, we'll always show you some plant and animal species that you could potentially find in that biome. We'll also always show you a world map color coded to the biome, and we'll always include a graph of climate data for a specific city or region whose position we indicate with a flag on the map. Now tropical rainforests are known for having extremely high biomass and biodiversity. In fact, they're home to more than 50% of the world's animal and plant species.

And these tropical rainforests are found on or along the equator, and that gives them relatively hot climate all year round, which you can see here in this graph with, the red line being relatively high all year long. Also, as their name implies with the term rain, tropical rainforests have pretty high rainfall or precipitation throughout the entire year, and that supports dense vegetation. And that dense vegetation creates vertical layering that creates a wide array of habitats. So to give you a sense of what we mean by vertical layering, here at the top left, we've got this image showing you some of the different layers that you can find in the vegetation of a rainforest. So this here concludes our lesson, and I'll see you all in our next video.

Savannas (Tropical Grasslands)

This video, we're going to talk about savannahs, which are also sometimes referred to as tropical grasslands. Now savannahs are really just a mixture of expansive grasslands with scattered trees, and those scattered trees are what differentiate them from regular grasslands. Now these savannas are found along the equator in tropical and subtropical regions, which is what gives them a pretty warm climate all year long. What's really important to note is that these savannas have a long dry season, which you could see here in this climate graph where most of the months are going to have relatively low precipitation bars, and it's really only these few months here that have significantly high precipitation bars. So that's a wet season.

And so the long dry season that's characteristic of these savannas causes frequent wildfires, and those wildfires are an important disturbance in these savannas. And so many of the plant and animal species have evolved adaptations to survive the droughts and the dry season and to tolerate the wildfires. So that concludes this video. I'll see you all in our next one.

Hot & Cold Deserts

In this video, we're going to talk about hot and cold deserts. Now, deserts are characterized by having extremely low annual precipitation, as you can see in this climate graph down below with these really low bars. They have really low net productivity, meaning they have low amounts of vegetation, and they have low biomass, meaning that there's not a lot of life in general. Now the temperature in deserts is actually highly variable, seasonally, daily, and regionally. So notice that in this map of the world here, we've tried to classify deserts as being either hot or cold deserts to give you a sense that the temperature varies drastically.

Now plants and animals in deserts have evolved to conserve water and to tolerate the dry conditions since, again, liquid water is quite scarce in deserts. So this here concludes our video, and I'll see you on our next one.

Terrestrial Biomes: Near Equator Example 1

So here we have an example problem that wants us to appropriately label each biome on the following climograph, which we can see down below right here. A climograph is really just a graph of climate data. Notice on the x-axis, we have the annual mean precipitation in units of millimeters, and on the y-axis, we have the annual mean temperature in units of degrees Celsius. The three biomes that we need to label are Savannah, desert, and tropical rainforest. The three regions on the graph are this green region, this pink region, and this yellow region on the far left. Recall from our previous lesson videos that tropical rainforests are found in tropical and subtropical regions very close to the equator and therefore have a relatively warm climate throughout the year with very little variation in temperatures.

We expect that the plot here to have, you know, very little variation on the y-axis, to be kind of squished vertically, if you will. As the term rain implies, tropical rainforests have the highest annual precipitation of any terrestrial biome. Notice that this green curve corresponds exactly with what we described. It has extremely high annual precipitation and has very little variation vertically on the y-axis and is appearing quite high on the y-axis, so it has warm temperatures. This green plot that you can see here is going to correspond with the tropical rainforest, which is letter c.

Now, the desert, recall from our previous lesson video, is quite variable in terms of its temperature. There are hot deserts and cold deserts. However, what is common to all deserts is that they have extremely low annual precipitation. Notice that the plot with the lowest annual precipitation is this yellow plot that you can see right here on the far left, and it does have quite a lot of variation here in terms of the annual temperature. But even this plot right here would be considered more of a warm or hot desert because colder deserts, like Antarctica, would have average temperatures that are well below 0. However, we can still label this yellow plot as a desert, which is option b here, so we can move on.

And then, of course, the last region here in pink must be the savannah, which we know that savannahs are going to be in tropical and subtropical regions, so they have warmer temperatures, but their temperatures vary a little bit more than the tropical rainforests do. They also have dry and wet seasons, so we expect the annual rainfall to be, you know, kind of in between somewhat what you can see here. This here concludes this example problem, and I'll see you in our next video.

What is the primary reason that the 3 warmest biomes (tropical rainforests, savannas & hot deserts) are located in equatorial & subequatorial regions?

• A. Less annual rainfall in this region.
• B. Less vegetation in this region to absorb heat from the sun.
• C. The sunlight strikes this region from a more direct and higher angle.
• D. All of the above.

In which biome is native vegetation best adapted to survive long droughts?

• A. Tropical rainforests.
• B. Savannas.
• C. Deserts.
• D. All of these.

Which of the following is the reason that deserts have a far lower net productivity & biomass than tropical rainforests & savannas?

• A. Deserts are too hot for any organisms to thrive.
• B. Extreme conditions such as lack of water & precipitation.
• C. Deserts have a lower biodiversity than tropical rainforests & savannas.
• D. Tropical rainforests & savannas are warmer than deserts.