Tropical savannas

Tropical regions contain higher species diversity than any other biomes in the world. This is attributed to their extensive area that creates many habitat types, their comparatively stable and warm climate with higher primary productivity, their long growing season, and the long time since they underwent major perturbations. Tropical savannas denote communities with an expanse of grass layer and scattered woody vegetation (shrubs and trees). They are found in tropical and subtropical regions, shaped by a succession of dry and wet seasons that differentiate them from other biomes.

Thus, savanna ecology is influenced by both grasses and woody plants, generally warmer temperatures throughout the year, and distinct wet and dry seasons. Summers are wet, hot, and humid, with most rainfall during this period, 15–25 inches (381–638 millimeters), while the dry season lasts for a longer period of the year (sometimes up to eight months) with warmer temperatures. However, the amount of rainfall and humidity in the savannas is not sufficient to support forest growth. Furthermore, high evaporative demands as a result of intense illumination cause savannas to experience a net water deficit for most of the year. Tropical savannas are maintained by complex and dynamic interactions among climatic factors, topography, edaphic factors, geomorphology, herbivory (grazing and browsing), fire, and human activities.

Savannas are generally categorized based on their canopy cover, spatial layout of woody plants, and stature. One of the resultant categories is savanna grassland, consisting of sparsely scattered trees or shrubs. On the other hand, savanna parkland comprises discrete patches of woody vegetation interspersed over a continuous herbaceous plant layer. Due to various abiotic influences such as soil, altitude, and topography, savannas are interrupted by bands or areas of woodlands, forests (riparian, groundwater, or montane forests) or wetlands, forming what are popularly called savanna landscapes.

Tropical savannas are known to be subclimax communities that are maintained by the soil characteristics (edaphic subclimax savannas), grazing (biotic subclimax savannas), and fire (pyric subclimax savannas). Termites are especially abundant in tropical savannas of the world, and their tall termitaria are conspicuous elements of the savanna landscape. Termites are important in soil formation, and their termitaria provide shelter for other animals. Termites are also important food sources for anteaters (endemics of the neotropical zoogeographic province) and aardvarks and pangolins in African savannas.

Tropical savannas are inhabited by the world’s proportionately large and rapidly growing human population, and a majority of their rangelands are dominated by livestock. Large population size associated with the prevalence of poverty increases the demand for immediate environmental resources. Overharvesting of timber and nontimber products, introduction of exotic species of plants and animals, overstocking, deliberate massive killing of wildlife, and fire suppression in some areas have significantly degraded tropical savannas, changing their scenery. There is a likelihood that with climate change impacts, tropical savannas might be potentially transforming into different vegetation types in some regions.

African Tropical Savannas

African savannas are grassland-dominated vegetation mixed with scattered and isolated trees found between latitudes 15 degrees north and 30 degrees south and longitudes of 15 degrees west and 40 degrees East. Savannas in Africa are found in several countries including Guinea Bissau, Sierra Leone, Liberia, Ghana, Somalia, Nigeria, Ethiopia, Ivory Coast, Benin, Togo, Central African Republic, Cameroon, Chad, Tanzania, Sudan, Democratic Republic of the Congo, Kenya, Angola, Malawi, Burundi, Uganda, Rwanda, Zimbabwe, Zambia, Mozambique, Botswana, Madagascar, and South Africa. The savannas occupy areas such as the Maasai steppe ecosystems in northern Tanzania and southern Kenya within the Somali-Maasai Regional Center of Endemism. Savannas in Africa also include the widely spread miombo woodlands spanning from southwestern Tanzania to Zambia, Malawi, Mozambique, Zimbabwe, parts of Botswana and Namibia, and Angola. Miombo is an extensive tropical savanna falling mostly under the Zambezian Regional Center of Endemism, and mostly characterized by plant species in the genera Isoberlinia, Julbernardia, and Brachystegia.

Flora and Fauna

In terms of plant species, savannas in Africa are characterized by such species as Acacia (mainly species from the Vachellia and Senegalia genera), miombo/mopane, candelabra trees, baobabs (Adansonia digitata), sausage trees (Kigelia africana), amarula plants (Sclerocarya birrea), Combretum species, star grass, elephant grass, Bermuda grass, and many more.

African savannas are known for their diversity of both invertebrates and vertebrates. Millions of animals are known to coexist and are spatially or temporally specialized to environmental resources in savannas. There are carnivores, including cats (lions, leopards, cheetahs, serval cats, and caracals); viverrids such as civets; dogs such as wild dogs and jackals, hyenids (aardwolves, spotted and striped hyenas); and mustelids (honey badgers). Herbivores include elephants, hippopotamuses, kudus (greater and lesser), giraffes, elands, topis, sable antelopes and roan antelopes, hartebeests, black and white rhinoceroses, wildebeests, gazelles, impalas, gerenuks, waterbucks, bushbucks, reedbucks, buffalo, zebras, oryx, dik diks, and sunis. These herbivores utilize different parts and types of plants, thus reducing competition and increasing coexistence between them.

There are also a large number of birds such as ostriches, vultures, doves, pigeons, eagles, shrikes, starlings, shoebills, storks, ducks, hammerkops, hornbills, and many others. Reptiles include snakes (venomous and nonvenomous), crocodiles, lizards, and tortoises. There are also amphibians such as frogs and toads, and many invertebrates, with insects accounting for the majority. Biota in African savannas interact in a complex way and produce a complex food web. Some animal species such as lions, elephants, and termites are keystone species maintaining diversity of the biomes. For example, elephants play the roles of ecosystem engineers, maintaining and creating vegetation structure, which increases usable habitat for other species.

Economy and Culture

Wildlife abundance and the multitude of cultures from the people residing in these areas make them attractive destinations for cultural tourism. San in Namibia and South Africa, Basarwa in Botswana, and Hadzabe in Tanzania and pastoralist groups (Maasai, Tutsis, and Ankole) persistently maintain their traditional ways of life. Other communities are composed of agropastoralists (peasants and small-scale livestock keepers). Preferred types of crops are maize, beans, peas, wheat, millet, cassava, coconuts, groundnuts, sugarcane, and cashews, and the common livestock include indigenous breeds of cattle, sheep, and goats.

Threats to African Savannas

The majority of community livelihoods in African savannas relies on the use of the immediate environmental resources for survival. People in these areas lack alternative livelihoods, which places direct pressure on natural biological resources, posing a greater threat to their survival. Indigenous trees are unsustainably harvested for construction, fuelwood, and charcoal production, while animals are illegally overhunted or captured for food and trade to satisfy the desires of the growing population in nearby towns and abroad for food and trophies. The tragedy of the ivory trade in recent years has increasingly jeopardized the survival of elephants.

Human-wildlife conflicts are prevalent in the African savannas. Conflicts between pastoralists on one side and African wild dogs and cheetahs on the other side have contributed to population declines and local extinctions in some areas. On the other hand, contact between wildlife and domestic animals can create outbreaks of zoonotic diseases such as rabies, canine distemper, and anthrax, claiming the lives of many wildlife, domestic animals, and human beings. Trampling by moving domestic animals creates loose and bare soils, which erode easily during rainy seasons but also suppress fire recurrence. The growing human population requires large areas for the expansion of settlement and agriculture; this creates encroachment into protected areas and blocks wildlife migratory corridors and dispersal areas. Ultimately, areas with wild animals (for example, protected areas) remain as ecological islands in the sea of human-modified landscapes.

Climate change and associated impacts invariably affect tropical African savannas, resulting in changed climatic patterns in some areas. Frequent drought occurrences in the greater Horn of Africa (including Kenya, Sudan, Ethiopia, and Somalia) dramatically reduce food production for humans and kill livestock (a major asset for most people) as a result of the loss of pasture and water.

Conservation Status

African savannas comprise some of the world’s major protected areas, differing in their conservation status, ranging from fenced national parks such as Kruger National Park in South Africa to the free-ranging wildlife in the major natural ecosystems such as the Serengeti in Tanzania. Other notable protected areas falling under the African savannas include Selous, Rungwa, and Moyowosi Game Reserves; Ruaha and Mikumi National Parks in Tanzania; Maasai Mara National Reserve, Amboseli, and Tsavo National Parks in Kenya; Luangwa Valley in Zambia; Gonarezhou in Zimbabwe; and the Great Limpopo Transfrontier Park straddling the borders between Mozambique, Zimbabwe, and South Africa. These areas preserve pristine habitats for wildlife and play a crucial role as representative areas for biodiversity conservation in the region annually visited by millions of tourists. Many countries in this region are members of international conservation treaties regulating the management of biological resources. These treaties include the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), the Convention on Biological Diversity (CBD), the Ramsar Convention on Wetlands, and the International Union for Conservation of Nature (IUCN), an international conservation organization.

South American Tropical Savannas

Tropical savanna also extends to South America in Llanos and Cerrado, but with relatively few species existing. Animals dispersing from the neighboring biomes play a key role in maintaining the diversity and persistence of this region.

Llanos in South America

Tropical savanna also extends to South America in Llanos and Cerrado, but with relatively few species existing. Animals dispersing from the neighboring biomes play a key role in maintaining the diversity and persistence of this region.

Brazilian Cerrado

The Brazilian Cerrado is an extensive open woodland savanna of short, twisted trees comprising 21 percent of the country. The Cerrado savanna extends from the Amazonian forest margin to outlying areas in the southern states of São Paulo and Paraná and into Bolivia and Paraguay. The Cerrado is a moister tropical savanna with rainfall ranging from about 31 to 63 inches (800 to 1600 millimeters) according to One Earth, with vegetation less adapted to waterlogging compared to its northern counterparts, the llanos of Venezuela and Colombia. The Cerrado has several endemic plants and animals, and is a biodiversity hotspot consisting largely of savanna ecosystems. Similar to other savannas, it is characterized by remarkably long dry seasons supporting drought and fire-adapted plant species. Common genera are Anisacanthus, Dicliptera, Geissomeria, Hygrophila, Jacobinia, Justicia, Lophoslachys, Mendoncia, Poikilacanthus, Ruellia, Staurogyne, Stenandrium, and Thunbergia.

The Cerrado is characterized by indigenous animal species such as edentates (tamandua, anteaters, and armadillos), marsupials (oposums), platyrrhine monkeys (marmosets, howlers, and capuchins), rodents (agoutis, pacas, capybaras, and many mouse-sized species) and the maned wolf. The Cerrado has a great diversity of animal life, though not in comparison to its counterpart in Africa.

Economy, Culture, and Threats in the Cerrado

In the past, the Cerrado domain was sparsely populated by backwoodsmen and Native Americans, typically Brazilian countrymen. In most cases, the country people kept livestock, cultivated crops, and utilized natural resources on a subsistence scale. In the past three decades, neoliberal changes in government policies have commercialized agriculture in the Cerrado leading to the encroachment of many areas for farming. Crops like soybeans, maize, rice, and cassava are commonly preferred. Invasive plant species have increased in number as a result of tree plantation and livestock fodder improvement. In 2022, it was estimated that more than 46 percent of the Cerrado had been cleared for crops or pastures. Construction of Brazil’s new capital city (Brasília) and its associated development also created demand for the growing urban population, which increased pressure on natural resources.

Another threat to Brazilian savannas comes from the Brazilian steel industry, which has historically relied heavily on charcoal as a source of energy. This places a remarkably high pressure on trees and is a major environmental threat. On the other hand, the expansion of agriculture has led to dramatic changes in water use in Llanos, diverting water to irrigation areas and drying up wetlands. Crops commonly cultivated are palm oil and rice, leading to the fragmentation of the once continuous ecosystem. Infrastructure development, construction of dikes and water channels, and road construction exacerbate habitat fragmentation. Furthermore, agricultural pesticides poison the ecosystem, leading to fatal consequences.

Conservation Status in the Cerrado

The value of the biodiversity-rich Cerrado and Llanos has always been undermined. When compared to other biomes, the Cerrado is considered to be poor and not even considered by the Brazilian constitution as a national heritage. Although less than 10 percent of the area is currently conserved, local conservation organizations collaborating with the World Wildlife Fund (WWF) are advocating for conserving and rescuing the biome. In 2022, the government of Colombia, WWF, and other organizations announced a $245 million agreement to protect 30 percent of the land and marine areas in Colombia by 2030.

Australian Tropical Savannas

Australia’s tropical savannas are landscapes of dense grass and scattered trees covering approximately one-quarter of the continent, about 733,594 square miles (1.9 million square kilometers). They cross the continent from Rockhampton on the east coast, across the Gulf of Carpentaria, to the Top End of the Northern Territory, and over to the Kimberley in western Australia. Australian savannas fall within the tropical latitudinal ranges of 10 degrees to 20 degrees south with medium to low mean annual rainfall. Climates are characterized by two distinct seasons: the wet and the dry, with high daytime temperatures and high evapotranspiration rates. The dry season lasts five to six months, usually from May to October. The wet season lasts five to six months from December to March. Australia’s tropical savannas are also referred to as the monsoonal tropics and the wet-dry tropics. The soils of Australia’s tropical savannas are generally poor, with the exception of some areas with basaltic or alluvial soils are relatively more fertile.

Australian Fauna and Flora

The Australian tropical savanna is one of the major biodiversity reservoirs, which is less intensively developed compared to the temperate areas of the world, and this accounts for its relatively intact habitat compared to that of southern Australia. The savanna hosts many hundred species of mammals, reptiles, birds, amphibians, native plants, and tens of thousands of invertebrate species. Many species in these groups are found nowhere else in the world. This part of Australia also has World Heritage areas like Kakadu National Park and Purnululu National Park.

Australian savannas contain many marsupials, mammals whose young are born undeveloped. These animals include the eastern gray kangaroo, the koala, agile and whiptail wallabies, wallaroos, possums, gliders, the northern quoll, and the golden bandicoot. Many of these animals live in or near the few trees in this area, utilizing them for shade, food, and water. Reptiles are also abundant in the tropical savannas. The saltwater crocodile, the world’s largest reptile, growing up to 23 feet (7 meters long), is found here. Associated with these are many species of birds, amphibians, and invertebrates, many of which are endemic to the region.

Open woodlands with grassy understory are the major vegetation type in Australia’s tropical savannas. Eucalyptus trees of restricted height (49 to 82 feet or 15 to 25 meters) and open canopy dominate Australia’s tropical savanna woodlands in areas receiving over 23 inches (600 millimeters) mean annual rainfall, with acacia or Casuarina species inhabiting the drier, and less fertile, areas. Eucalyptus species grow in warm climates and are the most important trees for timber, oil, and gum in Australia.

Australian Socioeconomic Activities

Australian savannas have a rich culture from the Aboriginal people, who have a long association with the land and much traditional knowledge of land management. The didgeridoo wind instrument and the band Yothu Yindi come from the tropical savannas. Tourists and locals also value the Australian tropical savannas for their wild and spectacular natural features. The main areas of employment include the livestock, conservation, tourism, mining, and horticultural industries. Until a few decades ago, livestock was the main economic base of the tropical savannas, accompanied by lesser but more intensive uses such as mining, agriculture, or urban development.

More recently, however, mining and tourism have become major economic industries alongside the pastoral livestock sector. Like many other savanna ecosystems, Australian savannas are home to a pastoral industry that includes some of the most extensive operations in Australia and manages the largest area of land of any group in the northern part of the country. The livestock industry is the major user and manager of land in the tropical savannas. It contributes hundreds of millions of dollars to regional economies across northern Australia and provides employment for thousands, both directly and indirectly via service industries.

The Australian tropical savanna is experiencing significant population pressure and land-use changes and is vulnerable to rapid land degradation. Other threats include habitat fragmentation, deforestation, climate change and variability, as well as frequent fires. In 2026, the Australian federal government approved the clearing of approximately 2,700 hectares of tropical savanna in the Northern Territory for agricultural development, raising concerns among environmental groups about potential impacts on threatened species such as the ghost bat, Gouldian finch, and red goshawk.

Asian Tropical Savannas (Terai-Duar Savanna)

Savannas cover a significant amount of Asia, spreading through Nepal, India, and Bhutan. These savannas are dominated by subtropical grasslands and shrublands in the Terai-Duar Savanna. The Terai or “moist land” is actually the belt of marshy grassland, savanna, and forest located at the base of the Himalayas, about 15.5 miles (25 kilometers) wide, but it is very long. The area is mainly found in humid subtropical and tropical climate regions at the base of the Himalayas.

The Asian savannas have originated over generations from woodland ecosystems through deforestation, abandoned cultivation, and burning, and are maintained at a subclimax by repeated grazing and burning. These mixed forces have led to the formation of mosaic types of savanna communities, depending upon the age, mode of origin, and the intensity of biotic disturbance. Savanna communities at different seral stages tend to differ in their biotic composition (that is, species composition, productive potential, and nutrient cycling).

Asian Fauna and Flora

The Asian savannas are home to diverse and abundant invertebrates and vertebrates. These include diverse amphibians, birds, and reptiles such as the gharial (Gavialis gangeticus). In 2025, the International Union for Conservation of Nature (IUCN) released the first Green Status assessment for the gharial (Gavialis gangeticus), classifying the species as “critically depleted,” with most remaining wild adults concentrated in the Chambal River system. There are also mammals, including tigers (Panthera tigris), pygmy hogs (Sus salvanius), swamp deer or barasingha (Cervus duvauceli), and the greater one-horned rhinoceros (Rhinoceros unicornis). The Terai–Duar savanna grasslands are home to three birds: the Slender-billed Babbler (Argya longirostris), gray-crowned prinia (Prinia cinereocapilla), and Manipur bush-quail (Perdicula manipurensis).

There are a number of plant species in the region including wild sugarcane (Saccharum spontaneum), 10-foot-tall tropical reeds (Phragmites kharka), and silky kangaroo grass (Themeda villosa). Smaller species include cogongrass (Imperata cylindrica) and six-weeks three-awn (Aristida adscensionis). Many of the grass species found in the Terai-Duar Savanna serve as fodder for livestock and wildlife species such as elephants and rhinoceroses, as well as cover for predatory species such as tigers.

Agriculture is the principal economic activity in the region. Other major employment sectors include livestock keeping, nature-based tourism, cultural tourism, and natural resource use. The main threats to the region include poaching for wildlife species, overgrazing, clearing for cultivation, population growth, irrigation projects, and water diversion.

Bibliography

“Cerrado.” OneEarth, www.oneearth.org/ecoregions/cerrado/. Accessed 4 Mar. 2026.

“Cerrado.” World Wildlife Fund, www.panda.org/discover/knowledge_hub/where_we_work/cerrado/. Accessed 4 Mar. 2026.

Cox, Lisa. “NT Environmentalists ‘Gobsmacked’ at Federal Green Light to Bulldoze Nearly 3,000 Hectares of Tropical Savanna.” The Guardian, 24 Feb. 2026, www.theguardian.com/australia-news/2026/feb/24/federal-green-light-bulldoze-tropical-savanna-northern-territory-threatened-species. Accessed 4 Mar. 2026.

Dinerstein, Eric, and Colby Loucks. “Asia: Bhutan, India, and Nepal.” World Wildlife Fund for Nature, 2016, www.worldwildlife.org/ecoregions/im0701. Accessed 4 Mar. 2026.

“Government of Colombia, WWF, and Others Announce $245 Million Agreement to Protect Vital Systems of the Nation’s Protected Areas.” World Wildlife Fund, 23 June 2022, www.worldwildlife.org/press-releases/colombia-wwf-and-partners-announce-245m-agreement-to-permanently-protect-vital-systems-of-nation-s-protected-areas. Accessed 4 Mar. 2026.

Rai, Sandeep. “Depleted, River-Dependent: IUCN’s First Gharial Green Status Assessment Calls for River Protection to Save Species.” The Times of India, 9 Oct. 2025, timesofindia.indiatimes.com/city/meerut/depleted-river-dependent-iucns-first-gharial-green-status-assessment-calls-for-river-protection-to-save-species/articleshow/124421785.cms. Accessed 4 Mar. 2026.

Ritter, Michael E. “Savanna Biome.” LibreTexts, geo.libretexts.org/Bookshelves/Geography_(Physical)/The_Physical_Environment_(Ritter)/13%3A_Earth_Biomes/13.03%3A_Savanna_Biome. Accessed 4 Mar. 2026.

Ruiz, Sarah. “Half of the Cerrado Is Already Gone. Here’s What That Means for the Climate.” Woodwell Climate Research Center, 8 Sept. 2022, www.woodwellclimate.org/half-of-the-cerrado-is-already-gone-heres-what-that-means-for-the-climate/. Accessed 4 Mar. 2026.

Senckenberg Research Institute and Natural History Museum. “Africa’s Savannas May Become Forests by 2100, Study Suggests.” ScienceDaily, 28 June 2012, www.sciencedaily.com/releases/2012/06/120628130643.htm. Accessed 4 Mar. 2026.

Smith, Jeremy M. B. “Savanna; Ecological Region.” Encyclopaedia Britannica, 7 July 2015, www.britannica.com/science/savanna. Accessed 4 Mar. 2026.

“Terai Duar Savanna and Grasslands in India.” IndiaNetzone, Indianetzone.com, 12 Sept. 2016, www.indianetzone.com/teraiduar_savanna_grasslands_india. Accessed 4 Mar. 2026.