Figure 19.9 Succession in shallow lakes and ponds. (a) The classical explanation for succession in these habitats describes a gradual and steady accumulation of organic matter that eventually fills in the basin and converts it to a terrestrial habitat. (b) More recent studies have demonstrated that the process can occur in occasional large bursts when droughts allow vegetation to extend along the dry part of the basin. When water becomes abundant again, the extended vegetation floats on the water’s surface and grows in thickness. Multiple drought events allow the vegetation to expand; eventually it covers the water’s surface and fills in the basin.

Based on A. W. Ireland, Drought as a trigger for rapid state shifts in kettle ecosystems: Implications for ecosystem responses to climate change, Wetlands 22 (2012): 989–1000.