Ash dieback is a communicable disease affecting ash trees in the UK. Describe how ash dieback spreads and explain the measures that can be taken to limit its spread.

Ash dieback is spread by airborne spores of the fungal pathogen Hymenoscyphus fraxineus. The spores are released from infected leaf litter and can travel long distances on the wind.

The disease can also spread through the movement of diseased ash plants or infected logs. When infected material is moved to a new site it can introduce the pathogen.

People and animals can carry spores on their clothing, boots, vehicles or equipment. Moving through an infected area and then travelling to a clean area can spread the disease.

To limit its spread:
1. Do not move infected ash plants or logs.
2. Burn or destroy infected trees and debris to remove the source of spores.
3. Wash animals, vehicles and boots after leaving an infected area to prevent carrying spores to new sites.