OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

What might be a direct effect of deforestation on local weather patterns?

1. Decreased occurrence of droughts

2. Increased frequency of severe storms

3. Stabilized temperatures throughout the year

4. Decreased soil fertility

The correct answer is: Increased frequency of severe storms

Deforestation can significantly alter local weather patterns, and one of the direct effects is an increased frequency of severe storms. Trees play a crucial role in regulating the water cycle by absorbing water and releasing it back into the atmosphere through a process called transpiration. When forests are removed, this mechanism is disrupted, leading to changes in precipitation patterns. Without trees, the local area can experience less evapotranspiration, resulting in drier conditions that could lead to more intense rainstorms when precipitation does occur. The absence of forest cover can also lead to a higher likelihood of temperature extremes, which may contribute to the formation of severe weather systems. Therefore, the loss of trees can enhance the conditions for severe storms, as the landscape becomes more susceptible to abrupt weather changes. This understanding reveals the interconnected nature of ecosystems and their significant influence on climate and weather.