PARENT SESSION
Contributed Oral Session 37: Floodplain Restoration
Tuesday, August 9, 8:00 AM - 11:30 AM, Meeting Room 513 A, Level 5, Palais des congrès de Montréal
Patterns of regional and local diversity in the California Bay-Delta ecoregion and its watersheds: Lessons for riparian restoration and monitoring.
Viers, Joshua *,1, 2, 3, Thorne, James1, 2, 4, Vaghti, Mehrey5, Quinn, James1, 2, 3, 1 Department of Environmental Science & Policy, Davis, CA, USA2 California Information Node (CAIN), Davis, CA, USA3 John Muir Institute of the Environment, Davis, CA, USA4 Conservation International, Washington, DC, USA5 Placer County Land Trust, Auburn, CA, USA
ABSTRACT- We have examined the distribution of riparian vascular plants at regional and local scales within the Sacramento - San Joaquin Bay-Delta Ecoregion to determine patterns and rates of species turnover. Our findings have important implications for the restoration and monitoring of habitats underway by the California Bay-Delta Authority (CBDA), an omnibus entity of state and federal agencies. Historically, California Bay-Delta rivers, including the Cosumnes and Sacramento, were a mosaic of diverse, dynamic floodplains, riverine and tidal marsh habitats, which supported exceptionally high biological productivity and influenced food webs of the Bay-Delta estuary. However, wetland reclamation, levee construction, invasive species, flow regulation, and flood control have altered the historic sources of productivity, and impacted the life histories of numerous native plants and animals. We feel that a priori expectations of species diversity and composition are necessary to better gauge restoration efforts and successes in general, and in the California Bay-Delta in particular. We compared regional riparian diversity from the CalJep geodatabase against localized plot observations to calculate expected diversity and composition of riparian flora in the study region. Our observations conclude that the Cosumnes River has become a de facto watershed-scale control for riparian diversity expectations within the larger CBDA ecosystem study, due to its relatively intact hydrograph and extensive tracts of seasonally-flooded riparian and floodplain habitat. Furthermore, longitudinal transitions in species composition and diversity on the main stem of the Sacramento River provide context for future adaptive restoration efforts. These findings will help provide a needed gauge to monitor, assess and forecast the efficacy of watershed restoration actions in the region.
Key words: riparian, restoration, diversity, california