Nature and extent of macropores in forest soils and their influence on subsurface water movement

Rain, falling on a sloping forested soil, may enter the soil quickly and move considerable distances through the soil by way of macropores. A macropore is a large pore, cavity, passageway, channel, tunnel, or void in the soil, through which water usually drains by gravity. Large quantities of water can move through the soil by way of these macropores-without appreciably wetting the soil mass. This phenomenon complicates the study and management of forested watersheds. A series of studies was undertaken to provide information about the nature, extent, and influence of macropores, as an aid to future studies and management of forest soils. This is a report on those studies.