wetlands can be part of the lentic system, as they form naturally along most lake shores, the width of the wetland and littoral zone being dependent upon the slope of the shoreline and the amount of natural change in water levels, within and among years. often dead trees accumulate in this zone, either from windfalls on the shore or logs transported to the site during floods. this woody debris provides important habitat for fish and nesting birds, as well as protecting shorelines from erosion.