Modeling seasonal dynamics of small fish cohorts in fluctuating freshwater marsh landscapes

摘要: Small-bodied fishes constitute an important assemblage in many wetlands. In wetlands that dry periodically except for small permanent waterbodies, these are quick to respond change and can undergo large fluctuations numbers biomasses. An aspect of landscapes mixtures marsh waterbodies is high rates biomass production occur the marshes during flooding phases, while serve as refuges biotic components phases. The temporal spatial dynamics ecologically important, provide a crucial food base higher trophic levels, such wading birds. We develop simple model analytically tractable, describing main processes spatio-temporal population small-bodied fish seasonal wetland environment, consisting waterbodies. expands into newly flooded areas wet season contracts declining water levels season. If dries completely times (a drydown), need refuge At least three new general conclusions arise from model: (1) there optimal rate at which should expand area maximize production; (2) also fluctuation amplitude level maximizes production, (3) upper limit on number reach waterbody drydown, no matter how surface drains waterbody. Because be manipulated wetlands, it useful have understanding role fluctuations.