Plant Life
The dominant plant type in tropical grasslands is, of course, grasses. The grasses of savannas tend to grow to 3 to 6 feet tall at their maturity, and serve as a source of food for many animals. The grasses are well-suited to the savanna's drier, warmer climate. Two rather common species of grass are Cynodon dactylon (Bermuda grass) and Pennistum purpureum (Elephant grass). Both of these grasses grow very densely and happen to be very invasive. This invasive tendency is necessary due to the frequency of drought and wild fires that so often ravage the savannas. These grasses also reproduce in a manner suggestive of an r-selected life history strategy, as they start to put out seeds around 3 months after their original planting. They also reproduce using a variety of methods, by seeds, runners, and rhizomes (underground stems that shoot new roots up to the surface).
Some drought-resistant and/or fire-resistant trees do manage to survive to maturity in savannas, though tree growth tends to be very scattered and isolated. One particular species of tree, the Adansonia digitata (Baobab tree), is found around the equator, in the savannas of Africa and India, and is both drought and fire-resistant. Baobab trees collect and store water in their corky, fire-resistant trunks during the wet months of the year, allowing them to survive through the dry months ahead. A few other key trees in savannas are acacia trees and eucalyptus trees, which both are a main source of food for different savanna animals.
Some drought-resistant and/or fire-resistant trees do manage to survive to maturity in savannas, though tree growth tends to be very scattered and isolated. One particular species of tree, the Adansonia digitata (Baobab tree), is found around the equator, in the savannas of Africa and India, and is both drought and fire-resistant. Baobab trees collect and store water in their corky, fire-resistant trunks during the wet months of the year, allowing them to survive through the dry months ahead. A few other key trees in savannas are acacia trees and eucalyptus trees, which both are a main source of food for different savanna animals.
Animal Life
The savanna grassland biome is home to a variety of animals, many of which are rather well-known. In Africa, some more well-known animals are lions, zebras, giraffes, ants, and multiple species of birds. Koalas and emus inhabit the savannas of Australia.
African savannas provide habitat for the Loxodonta africana, or African elephant. The African elephant is a keystone species of the savanna in Africa, they help to maintain the "grassland" status by preventing different trees, like the acacia, from growing to maturity. This prevents the savanna from experiencing large areas of tree growth, which would prohibit the growth of grasses by using all of the sunlight that the grasses need to grow.
Another important animal in tropical grasslands is the termite. There are thousands of species of termites, with 263 different species in Australia alone. In the grasslands of Australia in particular, termites build nests as well as impressive mounds that can reach heights of around 5 meters tall. Termites are detritivores, and so their consumption and defecation of cellulose from trees and other flora helps to cycle nutrients through their habitats and the ecosystem at large. A special ability of termites is their ability to survive the dry season of their savanna biome, with the help of their moist nests/mounds, unlike other detritivores and decomposers, which tend to perish during the dry season. Recently, scientists have begun to consider termites as an indicator to monitor the soil quality of tropical grasslands, recognizing their importance in the ecosystem. (http://www.savanna.org.au/all/termites.html)
African savannas provide habitat for the Loxodonta africana, or African elephant. The African elephant is a keystone species of the savanna in Africa, they help to maintain the "grassland" status by preventing different trees, like the acacia, from growing to maturity. This prevents the savanna from experiencing large areas of tree growth, which would prohibit the growth of grasses by using all of the sunlight that the grasses need to grow.
Another important animal in tropical grasslands is the termite. There are thousands of species of termites, with 263 different species in Australia alone. In the grasslands of Australia in particular, termites build nests as well as impressive mounds that can reach heights of around 5 meters tall. Termites are detritivores, and so their consumption and defecation of cellulose from trees and other flora helps to cycle nutrients through their habitats and the ecosystem at large. A special ability of termites is their ability to survive the dry season of their savanna biome, with the help of their moist nests/mounds, unlike other detritivores and decomposers, which tend to perish during the dry season. Recently, scientists have begun to consider termites as an indicator to monitor the soil quality of tropical grasslands, recognizing their importance in the ecosystem. (http://www.savanna.org.au/all/termites.html)