Distribution of Biomes
Introduction
The savanna biome is a vast, grassy plain that spans across tropical and subtropical regions of the world, including Africa, South America, Australia, and India. Savannas are characterized by their open, grassy landscapes dotted with a few scattered trees and shrubs. The climate in savannas is typically hot and dry, with distinct wet and dry seasons.
The savanna biome is home to a diverse array of plant and animal species. Grasses dominate the landscape and provide food for large herbivores such as elephants, giraffes, and zebras, while predators like lions, cheetahs, and hyenas hunt for their prey in the open plains. The savanna biome is also home to a variety of bird species, reptiles, and insects.
Savanna Biome
The savanna biome is a type of grassland ecosystem characterized by a continuous cover of grasses, with scattered trees and shrubs. It is found in regions with a tropical or subtropical climate, and is typically located between tropical rainforests and deserts.
Tropical wet and dry climate is known as Savanna Climate
This Savanna biome extends in both the hemispheres between 10°-20° latitudes and includes Columbia and Venezuela; South Central Brazil, Guiana, Paraguay (all in South America); hilly areas of the Central America; Central and East Africa (maximum extent in Sudan); Northern Australia and some areas of India (not original and natural)
Savannas are home to a wide range of wildlife, including large herbivores like elephants, giraffes, and zebras, as well as predators like lions, cheetahs, and hyenas. In addition to these iconic animals, savannas also support a diverse range of bird species, reptiles, and insects.
The soil in savannas is often nutrient-poor, and fire plays a crucial role in maintaining the ecosystem. Grasses are able to recover quickly from fires, while the trees and shrubs are more susceptible to damage. As a result, savannas tend to be dominated by grasses, with only a few scattered trees and shrubs.
Human activities, such as agriculture, grazing, and deforestation, have had a significant impact on savannas. Many savannas have been converted to agricultural land, which has led to soil degradation and the loss of biodiversity. Overgrazing by domestic animals can also have a negative impact on savanna ecosystems.
Conservation efforts are aimed at protecting and restoring savannas by promoting sustainable land use practices and limiting human impacts.
Climate
The savanna biome has a unique climate that is characterized by distinct wet and dry seasons. Savannas are typically found in tropical and subtropical regions of the world and have a warm to hot climate throughout the year.
During the wet season, which usually occurs during the summer months, savannas receive a lot of rainfall. This rainfall supports the growth of lush grasses and provides water for animals to drink. The wet season also coincides with the breeding season for many animal species, which take advantage of the abundance of food and water to reproduce.
In contrast, the dry season, which typically occurs during the winter months, is characterized by little to no rainfall. During this time, the grasses in savannas dry out and become brown and brittle. Many animals migrate to other areas in search of food and water during this time, while others have adapted to the dry conditions and are able to survive on the limited resources available.
Overall, the climate in savannas is one of the key factors that shapes the ecosystem. The alternating wet and dry seasons, along with the hot temperatures, provide unique challenges and opportunities for the plants and animals that call the savanna biome home.
- The Savanna climate is characterized by distinct wet and dry seasons, mean high temperature throughout the year and abundant insolation.
- Mean annual rainfall ranges between 250-500mm on the desert fringes of the Savanna and 1300-2000mm on its border with the equatorial climate.
- COOL DRY SEASON is characterized by high day-temperature ranging between 26°C- 32°C,
but relatively low temperature during nights, usually 21°C
- WARM DRY SEASON – is characterized by almost vertical sun’s rays, high temperature ranging between 32°C to 350C due to abundant insolation
- WARM WET SEASON – receives between 5O to 90 percent of the total annual rainfall.
Here is a table format showing the typical climate characteristics of the Savanna biome:
| Climate Characteristic | Description |
|---|---|
| Temperature | Generally warm to hot year-round with average temperatures ranging from 20°C to 30°C (68°F to 86°F) |
| Precipitation | Generally between 500mm to 1300mm (20-50 inches) of rainfall annually, with distinct wet and dry seasons |
| Wet Season | Occurs in the summer months (December to February in the southern hemisphere and June to September in the northern hemisphere) with heavy rainfall and thunderstorms |
| Dry Season | Occurs in the winter months (June to August in the southern hemisphere and December to February in the northern hemisphere) with little to no rainfall |
| Humidity | Generally low humidity levels due to high temperatures and dry air |
| Wind | Moderate to strong winds are common in the Savanna biome |
| Fire | Frequent wildfires are common during the dry season, which helps to maintain the grassland ecosystem |
| Climate Change Impacts | Climate change is expected to cause increased temperatures, altered precipitation patterns, and more frequent and intense droughts and wildfires in the Savanna biome |
It’s important to note that the climate of the Savanna biome can vary depending on factors such as latitude, altitude, and local weather patterns.
Rainfall
Rainfall is a critical factor in the savanna biome, as it determines the growth and distribution of plant species and plays a major role in the overall ecosystem dynamics. Savannas typically have a distinct wet and dry season, with the amount of rainfall varying greatly between the two seasons.
During the wet season, which usually occurs during the summer months, savannas receive a lot of rainfall. In Africa, for example, the wet season typically lasts from May to October and can bring up to 30 inches (750 mm) of rain. This rainfall supports the growth of lush grasses and other plant species, providing food and habitat for the many animals that inhabit the savanna biome. Rivers and other water sources also fill up during the wet season, providing drinking water for animals and supporting aquatic species.
In contrast, the dry season, which typically occurs during the winter months, is characterized by little to no rainfall. In Africa, the dry season lasts from November to April and can see only a few inches (less than 100 mm) of rain. During this time, the grasses in savannas dry out and become brown and brittle, and many plants go dormant. Many animals migrate to other areas in search of food and water during this time, while others have adapted to the dry conditions and are able to survive on the limited resources available.
Overall, rainfall is a critical factor in the savanna biome, and the alternating wet and dry seasons have shaped the unique ecology of these grassy plains.
Here is a table format showing the typical rainfall patterns of the Savanna biome:
| Savanna Biome Rainfall Patterns | Description |
|---|---|
| Rainy Season | The rainy season in the Savanna biome typically occurs during the summer months in the southern hemisphere (December to February) and the winter months in the northern hemisphere (June to September). During the rainy season, there is typically heavy rainfall, thunderstorms, and occasional flooding. |
| Dry Season | The dry season in the Savanna biome typically occurs during the winter months in the southern hemisphere (June to August) and the summer months in the northern hemisphere (December to February). During the dry season, there is little to no rainfall, which can lead to drought conditions and wildfires. |
| Annual Rainfall | The Savanna biome typically receives between 500mm to 1300mm (20-50 inches) of rainfall annually. The exact amount of rainfall can vary depending on the location of the biome, with some areas receiving more rainfall than others. |
| Distribution of Rainfall | Rainfall in the Savanna biome is often unevenly distributed, with some areas receiving more rainfall than others. This can lead to a patchy distribution of vegetation, with some areas having denser vegetation than others. |
| Importance of Rainfall | Rainfall is critical for the Savanna biome, as it supports the growth of grasses, shrubs, and trees. The timing and amount of rainfall can also influence the behavior of animals, such as the migration patterns of herbivores. |
It’s important to note that the rainfall patterns of the Savanna biome can vary depending on factors such as latitude, altitude, and local weather patterns.
Soil
Soil in the savanna biome is often nutrient-poor, as the grasses and other plants that dominate the landscape have adapted to the low-nutrient conditions. The soils in savannas are generally composed of sand or clay, with little organic matter.
One reason for the low nutrient content of savanna soils is the frequent fires that occur in the ecosystem. Grasses are able to recover quickly from fires, while trees and shrubs are more susceptible to damage. As a result, the grasses tend to dominate the landscape, and the nutrients that are present in the soil are quickly taken up by the fast-growing grasses. The frequent fires also prevent the accumulation of organic matter in the soil, which further contributes to the low nutrient content.
Despite the low nutrient content, savanna soils can support a wide range of plant species. Many grasses and other plants have adapted to the low-nutrient conditions, and some have developed deep root systems that can reach water and nutrients deep in the soil.
Human activities, such as agriculture and grazing, can have a negative impact on savanna soils. Overgrazing by domestic animals can lead to soil compaction and erosion, while the use of fertilizers and other chemicals can alter the delicate balance of nutrients in the soil. Conservation efforts in savanna biomes often focus on promoting sustainable land use practices that minimize the negative impact on soil and ecosystem health.
- Soils vary according to bedrock and edaphic conditions. In general, however, laterization is the dominant soil-forming process and low fertility oxisols can be expected.
- The famous Serengeti Plains in Tanzania are a grass savanna developed on droughty but nutrient-rich volcanic sands.
- The llanos of the Orinoco basin of Venezuela and Colombia are grass savannas maintained by the annual flooding of the Orinoco and Arauca rivers and their tributaries. The long periods of standing water inhibit the growth of most trees.
- Brazil’s cerrado is an open woodland of short-stature, twisted trees. high aluminum content of soils resulting from laterization on the ancient Gondwanan Shield of South America.
- The pine savannas of Belize and Honduras, in Central America, occur on sandy soils.
Here is a table format showing some of the typical soil characteristics of the Savanna biome:
| Soil Characteristic | Description |
|---|---|
| Soil Type | The Savanna biome is typically characterized by nutrient-poor, sandy soils with low levels of organic matter. The soil is often reddish or yellowish in color due to the presence of iron oxide minerals. |
| Soil Texture | The soil in the Savanna biome is typically sandy, with a coarse texture that allows for good drainage. This is important in areas with high rainfall, as it helps to prevent waterlogging and soil erosion. |
| Soil Depth | The depth of the soil in the Savanna biome can vary depending on the location, with some areas having deep soils that can support the growth of large trees, while others have shallow soils that are better suited for grasses and shrubs. |
| Nutrient Content | The soil in the Savanna biome is generally low in nutrients, particularly nitrogen and phosphorus. This is due to the rapid decomposition of organic matter in the warm, humid conditions, which results in the loss of nutrients from the soil. |
| Soil Acidity | The soil in the Savanna biome is generally acidic, with a pH range of 4.5 to 6.5. This can be a limiting factor for plant growth, particularly for crops and other plants that require more neutral soils. |
| Importance of Soil | Soil is critical for the Savanna biome, as it supports the growth of vegetation and provides habitat for a wide range of organisms, including insects, fungi, and microorganisms. However, the soil in the Savanna biome is under threat from factors such as deforestation, overgrazing, and climate change, which can lead to soil erosion and degradation. |
It’s important to note that the soil characteristics of the Savanna biome can vary depending on factors such as rainfall, vegetation, and underlying geology.
Vegetation
The vegetation in the savanna biome is characterized by a mixture of grasses, scattered trees, and shrubs. The grasses are the dominant plant species in savannas, covering much of the landscape and providing food for large herbivores such as elephants, giraffes, and zebras. The scattered trees and shrubs provide shade and shelter for these animals, as well as habitat for many bird and insect species.
The specific plant species found in savannas can vary depending on the region and the specific environmental conditions. In Africa, for example, the savanna biome is home to a variety of grasses, including Rhodes grass, red oats grass, and buffalo grass, as well as trees such as acacia, baobab, and mopane. In South America, the grasses are dominated by species such as Andropogon and Aristida, while trees such as palms and ceibas can be found in some areas.
The vegetation in savannas is adapted to the alternating wet and dry seasons that characterize the climate of these regions. During the wet season, the grasses grow tall and lush, while the trees and shrubs put out new leaves and flowers. During the dry season, many plants go dormant or lose their leaves to conserve water.
Fire is a natural and important part of the savanna ecosystem, playing a crucial role in shaping the vegetation. Grasses are able to recover quickly from fires, while trees and shrubs are more susceptible to damage. As a result, savannas tend to be dominated by grasses, with only a few scattered trees and shrubs. Some tree species in savannas have adapted to fire by having thick bark or being able to resprout after a fire.
THE GROUND LAYER (STRATUM) is dominated by various types of grasses and herbaceous plants. generally coarse, stiff and hard and of course perennials having the height of 50 cm but very long grasses reach up to 340cm (3.5m) in height. The African elephant grass attains the enormous height of 500cm (5m). The leaves of these grasses are almost flat which are shed during dry season but they are regenerated during wet season. The important genera of the Savanna grasses are elephant grass, Panicum, Pennisetum, Andropogon and African species Imperata cylindrica. The grasses bear deserted look during dry warm summer season but they become lush green again during humid summer season.
- THE MIDDLE LAYER consists of shrubs and very stunted woody plants.
- THE TOP OR CANOPY LAVER is formed by trees of various sorts. The general characteristics
of trees depend on the availability of water and moisture and therefore there is a great taxonomic variety of Savanna trees which are usually 6-12m in height.
- There are a few species of trees, which have developed such mechanisms which help them to
reduce evapotranspiration from their leaves during warm dry season and enable them to remain green even during dry season of deficient water supply.
- Tree species which cannot withstand dry conditions and therefore they shed their leaves and bear the characteristics of deciduous trees.
- The roots of the Savanna trees have also developed according to the environmental conditions as they are very large which can penetrate into the soil and ground up to the depths from 5m to 20m so that they can obtain water from groundwater even during dry season when the groundwater table falls considerably.
- The smaller plants and many herbaceous plants have special kinds of root systems characterized by root tubers and swellings so that they may preserve water which may be used by the plants during dry season.
The trees form flattened crown or canopy but they are very sparsely distributed. Several branches come out from the stems, trees are fire resistant (PYROPYlIC) as they have thick bark and thick bud-scales. monotony of tree species, For example, baobab is the only significant tree from Tanzania to Senegal and the Savannas of Ivory Coast and Sudan are dominated by palm trees. The important tree species are Isoberlinia, the baobab and dom palm in African Savannas; species of Eucalyptus such as E. Marginata and E. Calophylla in Australia; pine trees in Honduras etc.
Here is a table format showing some of the typical vegetation found in the Savanna biome:
| Type of Vegetation | Examples |
|---|---|
| Grasses | Rhodes grass, red oats grass, star grass, Bermuda grass, and buffalo grass |
| Trees | Acacia trees, baobab trees, umbrella trees, and shea trees |
| Shrubs | Wild sage, gooseberry, and leadwood |
| Forbs | Aloe vera, African daisy, and black-eyed Susan |
| Vines | Twining vines such as thunbergia and trumpet vines |
| Cacti | Euphorbia cactus and prickly pear |
It’s important to note that the types of vegetation found in the Savanna biome can vary depending on factors such as rainfall, soil type, and fire frequency.
Animals
The savanna biome is home to a wide variety of animal species, from small insects to large mammals. Many of the iconic African animals, such as lions, elephants, giraffes, and zebras, live in savannas, but savannas can be found on multiple continents, including South America, Australia, and Asia, each with its unique set of animal species. Here are some examples of the animal species found in savannas:
- Large herbivores: Savannas support large herbivores such as elephants, giraffes, zebras, and various species of antelopes, such as impalas, gazelles, and wildebeests.
- Carnivores: Lions, cheetahs, hyenas, and African wild dogs are some of the carnivorous species found in the savanna biome. These animals prey on the large herbivores and smaller mammals, such as hares and rodents.
- Birds: Many bird species can be found in savannas, including vultures, eagles, ostriches, and hornbills.
- Reptiles: Savannas are home to various reptile species, including snakes, lizards, and tortoises.
- Insects: The savanna biome is rich in insect life, including ants, termites, bees, butterflies, and beetles.
Many of the animal species in savannas have adapted to the unique environmental conditions, such as the seasonal availability of water and food, and the frequent fires that shape the ecosystem. For example, some species have developed specialized digestive systems to extract nutrients from tough, fibrous grasses, while others migrate to other areas during the dry season in search of food and water.
The African Savanna accounts for the largest number and the greatest variety of grazing vertebrate mammals in the world. For example, the East African Savanna carries 40 species of very large herbivorous mammals such as African buffalo, Zebra, giraffe, elephants, many types of antelopes, hippopotamus etc. of which even 16 species graze together in the same habitat. On the other hand the South American and Australian Savannas do not have large number of grazing mammals similar to the African Savanna but great variety of birds like those of the African Savanna is invariably found. The Australian Savanna is dominated by MARSUPIALS. 50 species of Kangaroo in the Australian Savanna, which greatly vary in size ranging from very large red Kangaroo (1.5m tall) to very small species of Wallaby (only 30 cm in height). The large grazing mammals of the South American Savannas include deer and guanaco. Besides, toucans, parrots, night jars, kingfishers, doves, finches, parakeets, wood peckers are also found in large number in the South American Savannas.
Relatively less denser cover of vegetation in the Savanna biome provides maximum mobility to the animals and thus the Savanna grasslands have been responsible for the origin and evolution of great number of large mammals (like elephant, giraffe, zebra, rhino, hippopotamus, antelopes etc.) and birds such as courses, bustards, game birds, ostrich, gazelles and several non-flying birds like emu.
The invertebrate animals include insects (such as flies – Diptera, locusts, grasshoppers, termites Isopetra, ants and arthropods (like spiders, scorpions etc.) which are found profusely in the various parts of the Savanna regions.
- Animals with little or no seasonal movement, e.g. giraffe, Grant’s gazelle, hartebeest etc
- Animals having partial movement during dry season, e.g. impala.
- Animals having partial movement during wet season, e.g. warthog, dikdik, waterbuck, rhino.
- Animals migrating during dry season, e.g. buffalo, zebra, wild beast, eland, elephant etc
- Reproduce in rainy season
Overall, the savanna biome is home to a diverse and complex ecosystem, with many fascinating and unique animal species.
Here is a table format showing some of the typical animal species found in the Savanna biome:
| Animal Species | Description |
|---|---|
| African Elephant | The African elephant is the largest land animal in the world and is found in the savannas of eastern and southern Africa. They are herbivores and feed on a variety of grasses, shrubs, and trees. |
| Giraffe | The giraffe is the tallest land animal in the world and is found in the savannas of sub-Saharan Africa. They are herbivores and feed on the leaves and shoots of trees, particularly acacia trees. |
| Lion | The lion is a large carnivorous mammal found in the savannas of Africa. They are apex predators and feed on a variety of prey, including zebras, antelopes, and buffalo. |
| Cheetah | The cheetah is a large, fast-running carnivorous mammal found in the savannas of Africa. They are known for their speed and agility and primarily feed on small to medium-sized antelopes. |
| African Buffalo | The African buffalo is a large herbivorous mammal found in the savannas of Africa. They are often found in large herds and feed on a variety of grasses. |
| Zebra | The zebra is a herbivorous mammal found in the savannas of Africa. They are known for their distinctive black and white stripes and feed on a variety of grasses. |
| Wildebeest | The wildebeest is a herbivorous mammal found in the savannas of Africa. They are known for their annual migration across the Serengeti and Maasai Mara ecosystems in search of food and water. |
| Warthog | The warthog is a herbivorous mammal found in the savannas of Africa. They are known for their distinctive tusks and are often found in groups called sounders. |
| Antelope | There are many species of antelope found in the savannas of Africa, including the impala, kudu, and gazelle. These herbivorous mammals feed on a variety of grasses and are preyed upon by carnivorous mammals such as lions and cheetahs. |
It’s important to note that the animal species found in the Savanna biome can vary depending on factors such as location, vegetation, and human activity. Additionally, many of these species are threatened by factors such as habitat loss, poaching, and climate change.
Conclusion
In conclusion, the savanna biome is a fascinating ecosystem found in various parts of the world, characterized by its unique climate, vegetation, and animal species. The savanna biome is known for its alternating wet and dry seasons, which have shaped the plant and animal life in this ecosystem. Grasses, scattered trees, and shrubs dominate the savanna vegetation, while large herbivores, carnivores, birds, reptiles, and insects make up the animal life. The savanna biome is also affected by human activities such as agriculture, grazing, and deforestation, which can have negative impacts on the delicate balance of this ecosystem. Overall, the savanna biome is a beautiful and complex ecosystem, highlighting the amazing diversity of life on our planet.