A delicate balance : Ecohydrological feedbacks governing landscape morphology in a lotic peatland

摘要: The Everglades ridge and slough landscape is characterized by elevated sawgrass ridges regularly interspersed among lower more open sloughs that are aligned parallel to the historic flow direction. Landscape degradation, topographic flattening, has coincided with a century of drainage, levee construction, nutrient enrichment, reductions. Here we develop conceptual model dynamics based on literature synthesis supported numerical PeatAccrete. We propose two feedback mechanisms govern characteristics. first, simulated PeatAccrete, involves differential peat accretion governed water level phosphorus concentration, leading attainment an equilibrium elevation relative slough. Differential accretion, however, cannot produce characteristic width or wavelength. Instead, between channel morphology sediment mass transfer controls lateral longitudinal features, consistent processes in anabranching rivers. This transport was critical pattern initiation evolution, redistribution from provides plausible mechanism for preventing gradual expansion. However, PeatAccrete results show that, absence transport, expand only order meters per century. result suggests combination factors driven widespread disappearance over past century, including altered vertical rates lead infilling. Sensitivity tests indicated changes duration depth surface inundation, supply, redox potential have way favors flattening. These relatively well defined compared role which requires further quantification. Because both positive negative interact Everglades, trajectory evolution time will depend upon current conditions, areas remnant topography being likely than degraded respond management ways enhance heterogeneity human timescales. Dual feedbacks important low-gradient peatlands worldwide pulsed, unidirectional flow.