Introduciton to Ecology and Regulation of Tidal Wetlands in Central California and the San Francisco Bay August 17, 2005 An introduction to the plants, soils, and hydrology of California tidal marshes John Callaway Department of Environmental Science University of San Francisco What’s happened to California’s wetlands? What percentage of California’s wetlands have been lost? a. 10 % b. 50 % c. 75 % d. 90 % e. 99 % Coastal Training Program Workshop Elkhorn Slough National Estuarine Research Reserve (NERR) San Francisco Bay NERR 1/10 1
Introduciton to Ecology and Regulation of Tidal Wetlands in Central California and the San Francisco Bay August 17, 2005 Wetland Loss in the United States Wetland Loss by State 25,000,000 400,000,000 early 1800's early 1800's 1980 1980 20,000,000 Wetland area (acres) Wetland area (acres) 300,000,000 size of Calif. 15,000,000 200,000,000 10,000,000 100,000,000 5,000,000 0 0 FL LA TX MN MI NC United States Alaska Lower 48 State (Dahl 1990) (Dahl 1990) SF Bay Wetlands Past and Present Wetland Loss by State 25,000,000 early 1800's 1980 20,000,000 Wetland area (acres) 15,000,000 10,000,000 ca. 1850 ca. 1998 5,000,000 0 CA OR WA FL LA TX MN MI NC State (Dahl 1990) (from SFEI) A Quick Introduction to Tidal Marshes Understanding Tidal Marsh Hydrology � Hydrology � Hydroperiod � tides � frequency of inundation � freshwater inputs � duration of inundation � Soils � lack of oxygen � depth of inundation � salinity � Critical hydrological factors � Vegetation � spatial patterns of distribution on a variety of scales � tides � adaptations � freshwater inputs � common species Coastal Training Program Workshop Elkhorn Slough National Estuarine Research Reserve (NERR) San Francisco Bay NERR 2/10 2
Introduciton to Ecology and Regulation of Tidal Wetlands in Central California and the San Francisco Bay August 17, 2005 Tides � Mixed, semi-diurnal tides on Pacific Coast � two highs and lows each day � different heights � Elevation relative to the tides determines inundation regime � Other coasts have different tidal patterns Tidal Variation across the Marsh regularly inundated rarely inundated high marsh - mid-marsh plain upland transition low marsh Importance of Tidal Creeks Freshwater Inputs � Large-scale variation up the estuary • deliver water, sediment and nutrients to marsh � Similar patterns up larger drainages • flush salts from soils � Finer-scale pattern within a marsh, and associated with any local freshwater inputs • more important in salt marshes than in brackish � VERY DIFFERENT than other US tidal and freshwater marshes marshes (mediterranean climate) Coastal Training Program Workshop Elkhorn Slough National Estuarine Research Reserve (NERR) San Francisco Bay NERR 3/10 3
Introduciton to Ecology and Regulation of Tidal Wetlands in Central California and the San Francisco Bay August 17, 2005 Spatial Variation in FW Inputs Salinity Variation across Salt and Brackish Marshes more regular salinity more variable salinity (higher in summer and • greatest input from Delta lower in winter) • significant local inputs at many local rivers/creeks, including: • Napa R. • Petaluma R. • Alameda Creek • Coyote Creek high marsh - mid-marsh plain upland transition low marsh Tidal Marsh Soils: Key Characteristics Tidal Marsh Soil Biogeochemistry � Fine texture (lots of clay and silt) � Driven by anaerobic processes � Poorly drained � Mix of aerobic and anaerobic zones in the soil � low oxygen levels (often no oxygen in soil) � Sequence of oxidation-reduction reactions � low redox status � O 2 , NO 3- , Mn 4+ , Fe 3+ , SO 42- , CO 2 (oxidized forms) � High organic content � H 2 0, N 2 , Mn 2+ , Fe 2+ , S 2- , CH 4 (reduced forms) � Moderate pH � Unusual nutrient dynamics � Unusual biogeochemistry (anaerobic conditions) � especially nitrogen Spatial Variation in Soil Factors Tidal Marsh Soils lower soil oxygen higher soil oxygen � Varying patterns across the marsh: less variable salt more variable salt � saturation/inundation � salinity � Seasonal patterns as well, especially salinity high marsh - mid-marsh plain upland transition low marsh Coastal Training Program Workshop Elkhorn Slough National Estuarine Research Reserve (NERR) San Francisco Bay NERR 4/10 4
Introduciton to Ecology and Regulation of Tidal Wetlands in Central California and the San Francisco Bay August 17, 2005 Spatial and Temporal Variability Plants: Key Factors Affecting Distribution � Spatial scales of variability � Inundation (anaerobiosis, oxidation/reduction) � estuarine-wide scale � Salinity (both summer stress and winter/spring � drainage scale lows for germination) � within wetland scale � Nutrients � Temporal scales of variability � Competition � climate change � History � inter-annual variation � seasonal changes (recruitment) Simplified Salt Marsh Plant Zonation Tidal Marsh Plant Distributions � Salt Marsh � Brackish Marsh � Freshwater Marsh high marsh - mid-marsh plain upland transition low marsh Salicornia virginica Salicornia virginica Spartina foliosa � Remember transitional-upland species!! Frankenia salina Distichlis spicata Grindelia stricta Zonation is similar in brackish marshes, Leymus triticoides but less obvious, and even less obvious in freshwater marshes. Plant Zonation Plant Adaptations � Anaerobiosis � physical adaptations � aerenchyma and adventitious roots � physiological adaptations � Salinity � secrete salt � other physiological adaptations (PWA and Faber 2005) Coastal Training Program Workshop Elkhorn Slough National Estuarine Research Reserve (NERR) San Francisco Bay NERR 5/10 5
Introduciton to Ecology and Regulation of Tidal Wetlands in Central California and the San Francisco Bay August 17, 2005 Salt Marsh Plants � Spartina foliosa (cordgrass) � Salicornia virginica (pickleweed) � Jaumea carnosa (jaumea) � Distichlis spicata (saltgrass) � Frankenia salina (alkali heath) � Cuscuta salina (salt marsh dodder) � Atriplex triangularis (spearscale, fat-hen) � Triglochin maritima (seaside arrow-grass) � Limonium californicum (salt marsh rosemary, sea lavender) � Grindelia stricta (gumplant) � Leymus triticoides (creeping wildrye) Coastal Training Program Workshop Elkhorn Slough National Estuarine Research Reserve (NERR) San Francisco Bay NERR 6/10 6
Introduciton to Ecology and Regulation of Tidal Wetlands in Central California and the San Francisco Bay August 17, 2005 Spartina foliosa Distichlis spicata Frankenia salina Limonium californicum Grindelia stricta Coastal Training Program Workshop Elkhorn Slough National Estuarine Research Reserve (NERR) San Francisco Bay NERR 7/10 7
Introduciton to Ecology and Regulation of Tidal Wetlands in Central California and the San Francisco Bay August 17, 2005 Scirpus maritimus Brackish Marsh Plants � Scirpus maritimus (NOW: Bolboschoenus maritimus ) � Scirpus californicus (NOW: Schoenoplectus californicus ) (Calif. tule) � Scirpus acutus (NOW: Schoenoplectus acutus ) (hardstem bulrush, tule) � Scirpus americanus (NOW: Schoenoplectus americanus ) � Typha angustifolia (narrowleaf cattail) � Typha latifolia (broadleaf cattail) � Juncus spp. (rush) � Salicornia virginica � Distichlis spicata � Jaumea carnosa � Atriplex triangularis � Baccharis pilularis (coyote brush) � Rosa californica (California rose) Scirpus californicus Scirpus acutus Scirpus americanus Freshwater Marsh Plants � Typha angustifolia � Typha latifolia � Scirpus acutus � Scirpus californicus � Juncus spp. � Polygonum spp. � Sagittaria spp. � Rubus spp. � Salix spp. � Lilaeopsis masonii � Mimulus guttatus � Lycopus americanus � Calystegia sepium � AND MANY OTHER SPECIES!! Coastal Training Program Workshop Elkhorn Slough National Estuarine Research Reserve (NERR) San Francisco Bay NERR 8/10 8
Introduciton to Ecology and Regulation of Tidal Wetlands in Central California and the San Francisco Bay August 17, 2005 Typha angustifolia Typha latifolia Rare Tidal Marsh Plants � Cordylanthus maritimus subsp. palustris � Cordylanthus mollis supsp. mollis � Cirsium hydrophilum � Aster lentus � Lathryus jepsonii var. jepsonii � Lilaeopsis masonii � AND MORE… Non-Native Tidal Marsh Plants Plant Summary � Spartina alterniflora (and hybrids with S. foliosa ) � Mix of physical and biological factors that affect plant distributions, including inundation and salinity � Lepidium latifolium (peppergrass) � Eichhornia crassipes (water hyacinth) � Diversity is reduced with higher salinity � Cotula coronopifolia (brass buttons) � Diversity is higher in the upper marsh � Polypogon monspeliensis (rabbit’s-foot grass) � Creeks have strong role in salt marsh plant � Rumex crispus (curly dock) distribution, not so prominent in brackish and � Phragmites australis (common reed) freshwater tidal marshes � AND MORE… � Upper marsh-transitional areas have many rare species, as well as many non-native invasives Coastal Training Program Workshop Elkhorn Slough National Estuarine Research Reserve (NERR) San Francisco Bay NERR 9/10 9
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