Terrestrial Biomes: Near Equator: Videos & Practice Problems

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

Tropical rainforests represent the first terrestrial biome we explore, characterized by their remarkable biomass and biodiversity. These ecosystems are home to over 50% of the world's animal and plant species, making them vital to global ecology. Located near the equator, tropical rainforests experience a consistently hot climate throughout the year, as illustrated by climate graphs showing high temperature averages.

Rainfall is another defining feature of tropical rainforests, with substantial precipitation occurring year-round. This abundant moisture supports dense vegetation, which in turn fosters a complex structure known as vertical layering. This layering creates diverse habitats, allowing various species to thrive at different heights within the forest. Understanding these characteristics is crucial for appreciating the ecological significance of tropical rainforests and their role in sustaining global biodiversity.

Savannas (Tropical Grasslands)

Savannahs, often referred to as tropical grasslands, are unique ecosystems characterized by expansive grasslands interspersed with scattered trees. This distinct feature sets them apart from typical grasslands. Located primarily along the equator in tropical and subtropical regions, savannahs experience a warm climate throughout the year.

A key climatic aspect of savannahs is their long dry season, which is evident in climate graphs that show low precipitation for most months, with only a few months experiencing significant rainfall, marking the wet season. This prolonged dry period contributes to the occurrence of frequent wildfires, which play a crucial role as a natural disturbance within these ecosystems.

Many plant and animal species in savannahs have developed specific adaptations to endure the challenges posed by droughts and wildfires. These adaptations are essential for survival in an environment where water availability fluctuates dramatically and where fire can reshape the landscape. Understanding these dynamics is vital for appreciating the ecological balance and biodiversity found in savannahs.

Hot & Cold Deserts

Deserts are unique ecosystems defined by their extremely low annual precipitation, which results in minimal vegetation and low biomass. This lack of moisture leads to a net productivity that is significantly lower than in other biomes. The climate in deserts is characterized by highly variable temperatures, which can fluctuate dramatically both seasonally and daily, as well as regionally. Deserts are typically classified into two main categories: hot deserts and cold deserts, reflecting these temperature variations.

In response to the harsh conditions, both plants and animals in desert environments have developed specialized adaptations to conserve water and endure the arid climate. These adaptations are crucial for survival, given the scarcity of liquid water in these regions. Understanding the characteristics and adaptations of desert ecosystems is essential for appreciating their complexity and the resilience of life within them.

Terrestrial Biomes: Near Equator Example 1

A climograph is a graphical representation of climate data, displaying annual mean precipitation (in millimeters) on the x-axis and annual mean temperature (in degrees Celsius) on the y-axis. Understanding how to interpret a climograph is essential for identifying different biomes based on their climate characteristics.

In this example, we are tasked with labeling three biomes: tropical rainforest, savannah, and desert, represented by distinct regions on the climograph. The green region corresponds to the tropical rainforest, which is typically found in tropical and subtropical areas near the equator. This biome is characterized by consistently warm temperatures with minimal variation throughout the year, resulting in a vertically compressed plot on the climograph. Additionally, tropical rainforests receive the highest annual precipitation of any terrestrial biome, which is evident in the green curve that shows high precipitation levels and low temperature variation.

The yellow region represents the desert biome. Deserts are known for their extremely low annual precipitation, regardless of whether they are classified as hot or cold. The yellow plot, located on the far left of the climograph, exhibits the lowest precipitation levels and significant temperature variation, indicating it is a desert. While this plot may represent a warm or hot desert, it is important to note that colder deserts, such as Antarctica, would show much lower average temperatures.

Finally, the pink region corresponds to the savannah biome. Savannahs are also found in tropical and subtropical regions, characterized by warmer temperatures that exhibit more variation than those of tropical rainforests. This biome experiences distinct wet and dry seasons, leading to annual rainfall levels that fall between those of tropical rainforests and deserts. The pink plot reflects these characteristics, making it identifiable as the savannah.

In summary, the climograph effectively illustrates the climate conditions that define each biome: the tropical rainforest (green) with high precipitation and low temperature variation, the desert (yellow) with low precipitation and high temperature variability, and the savannah (pink) with moderate precipitation and temperature variation.

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.

Answer: (C)

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

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

Answer: (C)

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.

Answer: (B)

Here’s what students ask on this topic:

What are the key characteristics of tropical rainforests near the equator?

Tropical rainforests near the equator are known for their high biodiversity, housing over 50% of the world's plant and animal species. They experience consistent high temperatures throughout the year due to their equatorial location. These biomes also receive significant rainfall year-round, which supports dense vegetation. This dense vegetation creates vertical layering, providing a wide array of habitats for various species. The combination of high biomass and biodiversity makes tropical rainforests crucial for ecological balance and biodiversity conservation.

How do savannahs differ from regular grasslands?

Savannahs, also known as tropical grasslands, differ from regular grasslands primarily due to the presence of scattered trees. These trees are not found in regular grasslands. Savannahs are located in tropical and subtropical regions near the equator, giving them a warm climate year-round. They have a long dry season with low precipitation, leading to frequent wildfires. These wildfires are an important ecological disturbance, and many plant and animal species in savannahs have evolved adaptations to survive droughts and tolerate wildfires.

What adaptations do plants and animals in deserts have for water conservation?

Plants and animals in deserts have evolved various adaptations to conserve water and survive the dry conditions. For example, many desert plants have thick, waxy cuticles to reduce water loss, deep root systems to access groundwater, and the ability to store water in their tissues. Animals may exhibit behaviors such as being nocturnal to avoid daytime heat, burrowing to stay cool, and having efficient kidneys to minimize water loss. These adaptations are crucial for survival in an environment with extremely low annual precipitation and variable temperatures.

Why is understanding tropical rainforests important for biodiversity conservation?

Understanding tropical rainforests is crucial for biodiversity conservation because these biomes house over 50% of the world's plant and animal species. The high biodiversity in tropical rainforests supports complex ecological interactions and contributes to global ecological balance. Conservation efforts in these areas help protect numerous species from extinction, maintain genetic diversity, and preserve ecosystem services such as carbon sequestration and climate regulation. Additionally, tropical rainforests play a vital role in sustaining indigenous communities and their traditional knowledge.

What role do wildfires play in the savannah ecosystem?

Wildfires play a significant role in the savannah ecosystem by acting as an important ecological disturbance. The long dry season in savannahs leads to frequent wildfires, which help maintain the balance between grasslands and scattered trees. These fires clear out dead vegetation, recycle nutrients back into the soil, and promote the growth of fire-adapted plant species. Many animal species in savannahs have also evolved to tolerate or even benefit from wildfires. Overall, wildfires help shape the structure and dynamics of the savannah ecosystem.