A marsh is a wetland that is dominated by herbaceous rather than woody plant species. Marshes can often be found at the edges of lakes, where they form a transition between the aquatic and terrestrial ecosystems. A wetland is a land area saturated with water, either permanently or seasonally, characteristics of a distinct ecosystem. Marshes develop along edges of rivers and lakes. Peat bogs are freshwater wetlands develop in areas with standing water, low soil fertility. Grasses, rushes or reeds, mosses mires acidic peat. Mangrove swamps are coastal wetlands. Most important factor producing is flooding. Duration of flooding determines whether resulting wetland has aquatic, marsh or swamp vegetation. 4K UHD 3840×2160