Savannas are the tropical version of the temperate grasslands. Most savannas are caused by climatic patterns where there is a strong dry season for a large part of the year. Few trees survive in these regions, but most savannas do have some form of trees that scatter the landscape. If you look at the map below you’ll realize that a large part of Africa, nearly half its landmass, is covered in some sort of savanna. Large tracks of savanna are also found in South America, India and Australia.
Warm, Wet, and Dry
Tropical grasslands are often sandwiched between tropical rainforests, which need a lot of rainfall year round, and desert biomes, which need almost no rain at all. They occur where it’s warm all the time (where temperatures rarely drop below 18 degrees Celsius) and where there’s a very rainy and humid wet season, and a drought-like and fire-prone dry season.
Coping with these extremes isn’t easy for the plants of tropical grasslands, but every species has adaptations to help it get by. Many of the grasses are dormant throughout the dry season; the trees often have leaves that fall off during the dry season to conserve water, very thick bark to protect against fire, water storage tissues in their trunks, or the ability to re-sprout really quickly after fire.
Tropical grasslands (or tropical savannas) are grass-dominated ecosystems with scattered shrubs or trees, which lie in a wide band on either side of the equator. Huge tropical grasslands exist in Africa, Australia, South America, and India, and some well known ones include the Serengeti Plains in Tanzania, Los Llanos in Venezuela and Columbia, and the Everglades in North America
Tropical grasslands support diverse groups of animals, which differ from region to region around the world. The grasses and trees of these ecosystems provide food for many large herbivorous mammals, which in Africa alone include: impalas, eland, gazelles, kudu, buffalo, wildebeest, zebra, rhinos, giraffes, elephants, warthogs, and more. These browsers and grazers manage to co-exist by having different preferences when it comes to food and where and when they eat.
Of course, where there are lots of herbivores, there are bound to be carnivores, too. Lions, leopards, cheetahs, jackals, wild dogs, and hyenas eat the grass- and tree-eaters on the savannas of Africa. Birds of prey, like hawks, eagles, and buzzards thrive in these environments as well, where they have wide, clear views to search for prey, hot air updrafts to help them soar, and essential resting and nesting sites in trees.
One of the most abundant but least seen animals in tropical grasslands is the termite. These ant-sized insects eat dead grass and wood and recycle the nutrients they contain back into the grassland ecosystem. Some species of termite in Africa, Australia, and South America build colossal mud mounds their colonies to live in that can reach more than five meters high!
Since tropical grasslands are great at supporting big, grass-eating mammals, they are often used by farmers as grazing grounds for livestock, which can cause them to degrade. Some tropical grasslands have had their makeup of grass and trees change dramatically because animals that wouldn’t usually live there have been forced in. And large areas of tropical grasslands all around the world have been cleared to make way for development. Because of these threats tropical grasslands need protection and careful management so they can remain one of our planet’s vast, complex, and critically important biomes.
Want to check out a tropical grassland in real life? Well, here are a few options you could investigate:
Explore the Serengeti Plains of Tanzania in Africa while you stay in the remote, southern part of these world famous grasslands at Sanctuary Kusini. Incredible wildlife can be seen here all year round.
Head to Venezuela in South America to experience Los Llanos (“the Plains”). The capital of Apure state is a town called San Fernando, and it’s located right in the heart of Los Llanos. Try not to have a close encounter with an anaconda on your Los Llanos adventures!
For something more hands-on, why not travel to the Everglades in Florida and help scientists find out more about this amazing grassland by doing some volunteer research? Everglades Hostel and Tours can help with both interesting work and a place to stay.