A cloud forest is generally a tropical or subtropical montane moist forest with persistent and frequent cloud cover. This particular micro environment exists in a narrow band of swirling mist and clouds usually at the canopy level. It is dependent on the local climate, the distance to the ocean, altitude and exposure to wind currents. Two thousand feet below or above this narrow band the atmosphere is clear, dry and usually sunny. Trees in the area exhibit gnarled trunks and branches, smaller leaves and a diminished height. An important feature of cloud forests is the way that the tree crowns intercept wind driven cloud moisture which then drips to the ground. This is separate from other precipitation and contributes to the hydrologic cycle on the dry side of the island of Hawaii.