Morphological and Physiological Responses of Scaevola sericea (Goodeniaceae) Seedlings to Salt Spray and Substrate Salinity

Abstract

The effects of substrate salinity and salt spray upon seedlings of Scaevola sericea were examined in this study. Three levels of substrate salinity: 0.0 ppt, 3,0 ppt, and 10,0 ppt were examined in' conjunction with three levels of salt spray: zero, medium (=200 mg·m-2·d-'), and high (=1200-1500 mg·m-2·d-1 ) . Leaf surface area, root to shoot ratio, as well as leaf, stem, and root mass decreased significantly (P :s 0.05) with increasing substrate salinity. Biomass accumulation was very low at 10.0 ppt substrate salinity, suggesting that higher levels of substrate salinity cannot be tolerated by the seedlings. Salt spray had a substantial effect on several of these variables, however its effects were less pronounced than those of substrate salinity. Cell sap osmolarity, leaf thickness, and leaf specific mass increased significantly (P :s 0.05) with both increasing substrate salinity and salt spray levels. Leaf carbon isotope ratios (oJ3C) became more positive with increasing salinity, indicating an enhancement of the intrinsic water use efficiency of the seedlings at higher salinities. Scaevola sericea is one of the dominant plants found at the leading edge of strand communities in the Hawaiian archipelago and throughout much of the tropical Pacific. Since substrate salinity and salt spray increase with proximity to the ocean, the two factors may act together to limit the seaward expansion of S. sericea in coastal habitats.

Responses of Kyllinga peruviana Lam. to Sea Water Spray

“…Also, inhibition of essential nutrients uptake must have led to chlorophyll reduction, because certain elements such as Mg 2+ and Fe 2+ are important for normal growth and are part of chlorophyll ultrastructure (Touchette, 2009). Similar to this study, Scaevola sericea seedlings had reduced stem mass, leaf mass, shoot mass and total biomass with increasing level of sea spray Goldstein et al (1996). Reduction in growth parameters must have led to biomass reduction.…”

Responses of common and successional heathland species to manipulated salt spray and water availability

“…Of the species tested, these two species are the most likely to be limited from growing in high salt spray, low water areas. We did not find a significant increase in leaf water content, which would be expected if plants altered leaf succulence as an adaptation to avoid salt spray stress (Boyce, 1951;Cartica and Quinn, 1980;Boyd and Barbour, 1986;Alpha et al, 1996).…”

“…We did not find a significant increase in leaf water content, which would be expected if plants altered leaf succulence as an adaptation to avoid salt spray stress (Boyce, 1951;Cartica and Quinn, 1980;Boyd and Barbour, 1986;Alpha et al, 1996). All species had decreasing predawn xylem pressure potential with increasing salt spray accumulation.…”

Patterns in specific leaf area and the structure of a temperate heath community

“…Many studies have documented similar changes in SLA after transplantation. SLA is known to vary with light availability (Huffman et al ., 1994; Onimaru & Yabe, 1996; Valladares et al ., 2000), as well as other abiotic variables such as nitrogen concentrations, water availability, salt spray and substrate salinity (Alpha et al ., 1996; Cramer et al ., 2000; Knops & Reinhart, 2000). Therefore, it should be reiterated that relationships between PFD and SLA do not necessarily imply that light is the only proximate mechanism influencing intraspecific patterns.…”