You can see the effect of a lightning strike here in Fairbanks or in the lower 48. What is the effect of a lightning strike farther north where there are no trees?
A lightning strike is a dangerous discharge and while they often strike trees, they can also go straight into the ground. However, lightning strikes do not necessarily need trees to start a fire; lightning strikes have caused fires in the tundra as well. Most of the time, however, lightning strikes do not have any consequences.