Impacts of Drought
Geography: Edexcel A Level, topic 7.2.2
The Impacts of Drought on Ecosystems
Drought leads to less water for the vegetation of an area. This can have devastating effects on an flora and fauna that interact in that ecosystem.
Ecosystem key terms
- Ecosystem functioning - the biological, chemical and physical processes that take place in an ecosystem.
- Ecosystem resilience - how capable the ecosystem is of surviving changing water levels.
- Deserts and semi-arid areas are the most resilient to drought.
Rainforest
- Prolonged periods of drought lead to forest stress.
- Younger trees die as a result of drought. This reduces the canopy cover.
- Reduction of canopy cover leads to less interception and infiltration but also decreases evapotranspiration. This means water vapour and rainfall reduces.
Forests
- Forests that are exposed to tropical sunlight with dead vegetation and a mass of dry organic material can easily set alight.
- Lightning storms and high winds can then turn a small fire into a wildfire.
- Croatia suffered from 2 ½ months of no rainfall during the summer of 2017. This lead to widespread drought and ultimately wildfires that were challenging to manage. Water-bombing planes were donated from nearby countries to control the flames.
Wetlands
- Drought increases the likelihood of tree mortality.
- A decrease in vegetation reduces the habitat for both wild or farm animals. Birds and wetland vegetation respond to drought differently. Drought can change communities by eliminating species and having knock-on impacts on the rest of the food chain.
- The likelihood of wildfire increases.
Wetlands example
- In Minsmere, Suffolk, wetlands species such as snipe and thrush are impacted by the dry soil surface which is present during a drought.
- The snipe and thrush are less able to penetrate the dry soil to reach the invertebrates they feed off.
Test yourself on Impacts of Drought
Forests are at risk from what when they are exposed to tropical sunlight?
What wetland species of bird in Minsmere, Suffolk, is impacted by the dry soil surface present during a drought?