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Filters: Tags: geographicDataset (X) > partyWithName: California LCC Data Manager (X) > partyWithName: San Francisco Bay Conservation and Development Commission (X) > partyWithName: California State Coastal Conservancy (X)

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Priority areas for conservation of tidal marsh birds given current and future environmental conditions. Maps were created using Zonation, a spatial conservation planning software tool that can take into account multiple species and scenarios to create a hierarchical prioritization of the landscape.The current (2010) and future (2030-2110) prioritization is based upon distribution and abundance models for five tidal marsh bird species which utilized avian observation data (2000 - 2009), a marsh accretion model, and physical variables (e.g. salinity, distance to nearest channel, slope, etc). Values represent the rank in which pixels were removed from the landscape using Zonation Conservation Planning software with...
Marsh accretion was modeled by ESA PWA using the Marsh-98 model, described here. The model assumes that rates of marsh plain elevation change depend on the availability of suspended sediment and organic material, water depth, and duration of inundation periods. If enough suspended sediment is available, then tidal marsh elevations can keep pace with increased inundation. Model outputs were linearly interpolated in 10-cm increments for starting elevations ranging from -3.7 to 1.7 m (relative to mean higher high water, or MHHW), and applied to a composite 5-m elevation grid (see below) for SF Bay. Results for each possible combination of projected sea level rise, sediment and organic material availability, and target...
Densities for five key tidal marsh-dependent bird species were modeled using boosted regression trees (Elith et al. 2008). The models are able to fit non-linear functions between environmental variables and the presence/absence or density of a species. Map values represent the probability of occurrence of a species or the density (birds/ha). Higher values in a map indicate a higher likelihood that a species will be present at a site. Bird species modeled: Common yellowthroat, black rail, clapper rail, marsh wren, song sparrow. Model outputs: Probably of occurrence, density (birds per hectare)
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.
Understanding San Francisco Bay’s vulnerabilities to sea level rise is important for both biodiversity conservation and for management of public infrastructure. Coastal marshes provide essential ecosystem services such as water filtration and flood abatement while also providing important habitat for species of conservation concern. Improving our understanding of how tidal marsh habitats will be affected by sea level rise is important so that we maximize ecosystem services that coastal marshes provide and ensure that endemic populations of plants and animals persist into the future. For this project, marsh accretion was modeled by ESA PWA (http://www.pwa-ltd.com/index.html) using the Marsh-98 model, described here:...
Current and projected bird distribution and abundance layers, updated with new model that has better inputs. Point Blue Conservation Science assessed the effects of sea-level rise (SLR) and salinity changes on San Francisco Bay tidal marsh ecosystems. Tidal marshes are naturally resilient to SLR, in that they can build up elevation through the capture of suspended sediment and deposition of organic material (vegetation). Thus, a “bathtub” model approach is not appropriate for assessing impacts to this dynamic habitat. Rather, dynamic accretion potential can be modeled annually based on tidal inundation, sediment availability, and the rate of organic accumulation (related to salinity).Working with researchers at...