Salinity and Inundation Influence Productivity of the Halophytic Plant Sarcocornia pacifica

Abstract

Salinity and inundation influence both wetland plant species diversity and productivity and are likely to change with predicted climate change. We investigated the degree to which these factors affect aboveground annual net primary production (ANPP) of pickleweed, Sarcocornia pacifica, at three tidal marshes spanning a salinity gradient in the San Francisco Bay Estuary, California, USA, including two natural marshes and one restored marsh. We collected S. pacifica biomass four times throughout the growing season, with roughly half of the collections in well-drained areas near channels and half away from channels, in areas of poor drainage. We examined the effects of site, channel drainage, and pore-water salinity on ANPP. Plots in well-drained areas had significantly greater biomass than those in poorly-drained areas. Most striking was the interaction between soil salinity and marsh drainage on aboveground productivity; salinity had a strong negative impact on ANPP in poorly-drained plots but had no effect in well-drained plots. In a recently-restored brackish marsh, productivity decreased with increasing distance to the nearest channel. These results suggest that within site hydrological dynamics have a strong influence over S. pacifica ANPP, with potential implications for the likely effects of shifts in salinity and inundation associated with climate change.

Distribution and Invasion Potential of Limonium ramosissimum subsp. provinciale in San Francisco Estuary Salt Marshes

“…Below MHHW, higher salinity and inundation likely limit the size and reproductive output of LIRA. This fits with prior studies of Limonium species (e.g., Boorman 1971) and with upper salt marsh species in general (e.g., Cooper 1982;Seliskar 1985;Schile et al 2011;Ryan and Boyer 2012). Since LIRA grows largest in low stress conditions, we suspect it may compete most aggressively within the transition zone.…”

“…Where abiotic stress is high (e.g., via hypersalinity, anaerobic conditions or extreme desiccation), plant species able to tolerate harsh environmental conditions succeed. But where abiotic stress is low (e.g., conditions of low salinity or moderate moisture), marsh halophytes often grow taller, and/or produce more seed (Seliskar 1985;Schile et al 2011;Ryan and Boyer 2012) and interspecific competition may become a more important factor structuring marsh communities (Pennings and Callaway 1992;Crain et al 2004). …”

Potential effects of sea-level rise on plant productivity: species-specific responses in northeast Pacific tidal marshes

“…For instance, recent work by Schile et al (2011) on S. pacifica in northern California suggests that soil drainage patterns, not just total inundation time, may be an important determinant of plant production. Plants in well-drained soils were more productive than those on the marsh plain.…”

“…This may affect estimates of optimal productivity in some species such as S. pacifica, which has been shown to be sensitive to soil drainage (Schile et al 2011, but see Mahall & Park 1976b, who suggested that the distribution of S. pacifica is insensitive to soil oxygen availability). If the mesocosms contained more anoxic sediment than un-manipulated marsh at the same tidal elevation, optimal productivity may have been shifted higher in the tidal frame relative to the marsh.…”

Coastal wetlands of temperate eastern Australia: will Cinderella ever go to the ball?

“…Hickey and Bruce 2010;Prahalad et al 2011) but, good as it is, the recent Australian effort lags behind what is being achieved for coastal wetlands in the Northern Hemisphere (e.g. Crain et al 2004;Sala et al 2008;Erfanzadeh et al 2010;Alleman and Hester 2011;Schile et al 2011) and, it could be argued, current efforts do not match the scope or power of the studies undertaken half a century ago by Lesley Clarke and Nola Hannon (1967, 1969, 1970, 1971 with the mangroves and saltmarshes of Botany Bay, New South Wales. Moreover, the research effort is scattered and uncoordinated; the contrast with inland systems, especially in the Murray-Darling Basin, is stark, as in the latter there are organisations such as the MurrayDarling Basin Authority, National Water Commission, and Smart Water Australia to plan research strategies and to coordinate research undertakings.…”