Maps of the probability of occurrence of tidal marsh plant species were created using generalized additive models (Hastie and Tibshirani 1990). Species modeled: Saltgrass, alkali-heath, SF Bay gumplant, jaumea, wirerush, pepperweed, giant reed, pickleweed, hard-stem tule, three-square bullrush, smooth cordgrass, California cordgrass, cattail.