When Winter Gives Dead Branches Hair

Hair ice is a rare form of ice that resembles human hair, forming on dead hardwood branches in specific conditions. It requires temperatures just below 0°C, high humidity, and the presence of the fungus Exidiopsis effusa. The process involves ice segregation, where supercooled water in the wood forms ice strands. The fungus secretes proteins that prevent recrystallization, allowing the ice to maintain its unique structure. This phenomenon occurs in forests between 45° and 55° north latitude.

What is the primary reason hair ice is considered rare?

• It requires specific fungi and conditions to form.

• It forms at temperatures above 0 degrees Celsius.

• It forms only on living trees.

• It can only be found in tropical regions.

Which of the following conditions is NOT necessary for the formation of hair ice?

• Presence of dead rotting branches.

• Temperature just below 0 degrees Celsius.

• High levels of sunlight.

• High humidity.

What is the process called that leads to the formation of hair ice strands?

• Ice crystallization

• Ice segregation

• Ice sublimation

• Ice evaporation

Why is it important for the air to be humid during the formation of hair ice?

• To ensure the ice strands grow faster.

• To prevent the ice from melting.

• To increase the temperature of the wood.

• To prevent the ice from sublimating into vapor.

What role does the fungus Exidiopsis effusa play in the formation of hair ice?

• It secretes proteins that prevent recrystallization.

• It prevents the ice strands from melting.

• It helps the ice strands grow longer.

• It increases the temperature of the wood.