Impact of Human Activity on the Savanna
- Savannas provide water, grazing and foraging, food and fuel for millions of people
- The unique biodiversity of savannas, encourages and supports wildlife tourism
- However, human impacts are causing widespread and accelerating degradation of savannas
- The main threat is land use change
- Landscape fragmentation which disrupts herbivore communities
- Human changes to fire regimes
- Climate change and rising atmospheric CO2
- Unsustainable water use and irrigation methods
- Land clearance reduces grazing for herbivores and fragments the landscapes reducing their community connectivity
- Grass is burned off to ensure improved grass growth the following season, it also prevents woodlands from taking over
- Large fires decimate flora and fauna communities - especially those not fire-resistant, however, fires can also kill insects and small animals, providing food for predators
- Woody plants are killed by cattle eating their foliage, allowing thorny, animal repellent trees to become dominant
- Poor agricultural practice can lead to soil degradation and desertification
- Over grazing further exposes the grasslands to erosion
- Tourism attracts the use of transport which damages vegetation and disturbs wildlife and affects breeding grounds
- Conservation through national parks if variable - some parks attract illegal trophy hunting
- Products such as ivory and rhino horn - where the animal is killed just for their tusks
- Hunters target large males, leading to an imbalance in the population
- Animals can become embolden and attack people
- Human rubbish can be poisonous to animals
- Demand for illegal bushmeat is a growing commodity, adding pressure to the savanna ecosystem
- Plants are overharvested due to their commercial value - baobab tree fruit, African Blackwood for carving, Gum Arabic for chewing gum etc.
- The Gum Arabic tree is an important plant to the Sudan, as it supplies 80% of the worlds export of gum. Gum Arabic is used extensively in pharmaceuticals, food production, and traditional medicine
Exam Tip
Overgrazing is a positive feedback loop, because it reduces plant density, which increases pressure on the remaining grassland, this leads to more overgrazing and eventually soil degradation and erosion.