Wet meadow ecosystems in the highly seasonal climate of the Sierra Nevada, CA, depend on groundwater throughout the dry summer growing season.  Meadows in California that have been extensively studied will be used to demonstrate the influence of hydrologic processes on vegetation patterning.  These examples will include data on vegetation compostition, water table depth, and remotely sensed images of vegetation patterning.

Results/Conclusions

The regional source and quantity of groundwater feeding the meadow system is a primary determinant of vegetation composition and patterning in this groundwater dependent ecosystem.  Within the meadow, the hydraulic properties of the meadow sediment, the geometry of the meadow, and the flux of water across the meadow boundaries determine the configuration of the water table.  It is this configuration of the water table as well as meadow topography that determine vegetation composition and patterning.  Hydroecological changes to these systems have and continue to occur as a result of stream incision, installation of drainage ditches, land use practices, climate change and restoration/rehabilitation efforts.  Quantitative predictions of these changes can be made and an improved understanding of these systems can be developed through improvement of coupled hydrologic and vegetation models.