Human Activity & Savanna Grasslands (AQA A Level Geography)

Many savannas are in LDEs and have an expanding human population, which increases pressure on the biome

Increased conflict between people and animals of the savanna. Crop raiding, livestock or people killed by wildlife, can lead to retaliation against wild animals

Nomadic communities are becoming more static, because of their growing community size and land now used for feeding and housing has grown. This results in livestock being grazed in smaller areas, leading to overgrazing

More land is utilised for subsistence crops, to feed the growing local populations in savannas

Prosperity and development has increased; leading to increased demands in food and goods. This leads to agricultural land use changes

Tourism can boost economic development and income can be used for further conservation 

Tourism brings habitat loss from road and hotel construction, disturbance of animals and their breeding

Advances in agricultural practices and crop types, have led to commercial farming on the savannas and planting large areas with cash crops, such as corn and wheat.

Newly created varieties of soybeans are now grown in Brazil’s savanna, even though soybeans are only suitable for farming in temperate climates

Overcultivation due to lack of crop rotation, had led to soil nutrient depletion as the soil cannot recover before being replanted

Salts in the soil can dissolve in water when land is irrigated. As water evaporates, salts rise to the surface and form a salt crust which kills many plants

Over abstraction of water, lowers the water table, so plants and animals cannot reach it 

Overgrazing and intensive agriculture are unsustainable and often leads to soil erosion, due to lack of root binding

Desertification is increasing due to poor management of these activities. Poor soil conditions make it hard for vegetation to regrow, creating patches of desert like conditions

The problem is expected to worsen as climate change alters rainfall patterns

Controlled fires are necessary, however, if fires are prevented or extinguished too quickly, organic material builds up and massive uncontrolled fires can occur, which decimate habitats and imbalances the ecosystem

Water is scarce during the dry season, so it requires careful management in its usage (irrigation, domestic use etc.)

Game reserves have been created in many areas, prohibiting local settlements, grazing and farming and hunting is strictly controlled. This can increase sustainability by allowing the ecosystem to operate without human interference. However, they also cause conflict between locals and officials, where locals have been used to foraging/farming within the park lands prior to exclusion

Humans are directly reducing savanna biodiversity by destroying habitats and killing wildlife

Changing land use is also causing fragmentation, which can be problematic as grazing animals and predators need large areas to roam

The presence of domestic livestock reduces the amount of vegetation and available water for native wild herbivores. Domestic species are replacing wild species in the ecosystem

Native savanna species are also threatened by invasive species, e.g. cane toads were introduced in the Australian savanna as a form of crop pest control, but their population rapidly expanded, putting native species under threat through eating their food and secreting poison when threatened