The effect of tidal exclusion on salt marsh vegetation in Baja California,México

Changes in salt marsh vegetation were analyzed over a two-year period (November 1984–November 1986) following the construction of a dike in the southwest corner of Punta Banda Estuary, Baja California, México. Changes included: increased interstitial soil salinity, reduced soil moisture, increased mortality of Spartina foliosa and decreased middle marsh species diversity due to the elimination of annual and short-lived species. The sea-side edge of the middle marsh shifted its boundary to a lower elevation. By the end of 1986, dominant species were Salicornia virginica, Batis maritima and Frankenia grandifolia. By October 1988, only a few patches of S. foliosa persisted at the water edge, and it appeared that the community was not yet stable. The potential future of the estuary is evaluated.