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winter or early spring drawdowns encourage dock, smartweeds, swamp timothy, and <br /> watergrass. Drawdowns in May or June encourage cattail, bulrush, cockleburs, and alkali <br /> bulrush. Seasonally flooded marshes are usually flooded from 10- 20 inches in depth, <br /> with some deeper areas to support diving birds and small fish. <br /> In these wetlands, management has tended to emphasize plant production. Summer <br /> irrigation of seasonal marshes, moist-soil management, tends to select for a mixture of <br /> annual grasses and forbs and produces higher seed production than non-irrigated wetlands. <br /> Irrigation is a good technique to develop a diverse seed bank in a relatively short period of <br /> time (2 years). <br /> Invertebrate management has now taken hold as a viable management technique. Euliss <br /> and Grodhaus (1987) has shown evidence that flood-up of pools within seasonal marshes <br /> prior to fall flood-up of the larger units, provides for an early bloom of invertebrates and <br /> increased biomass. Managers at the Cosumnes Preserve have taken this one step further <br /> by providing deepened areas in each impoundment and then cycling water depth every <br /> three to four weeks from September through early December. This action produced high <br /> numbers of insect and invertebrates that, during drawdown periods, provide concentrated <br /> food resources for migratory shorebirds, ducks, herons, cranes, and blackbirds. <br /> Typically these wetlands are available to the millions of migratory waterbirds wintering in <br /> the Great Valley. Ducks, geese, swans, sandhill cranes, shorebirds, herons, egrets, and <br /> many wetland passerines like blackbirds readily exploit these habitats. Migrant raptors that <br /> forage on migrating waterbirds (peregrine falcon and merlin) also frequent these wetland <br /> habitats and often follow migrating birds from the Arctic breeding grounds. <br /> Buckeye Ranch Resource Plan (November, 1993) <br /> 181 <br />