The effect of salinity on the growth of some New Zealand sand dune species

Abstract

Soil salinity affects many coastal communities, but it is not clear to what extent salinity is involved in the distribution ofsand dune vegetation. Twenty-nine species (including nine exotic species) found on New Zealand sand dunes were used in a study of root-salinity tolerance. Six concentrations of salt were added to plants grown in water culture; growth rates and the percentage oflive material were measured.About half the species were more intolerant of root-salinity than the glycophytic control (wheat). These were mainly native New Zealand herbs and grasses and the introduced species Silene gallica and Lupinus arboreus. Tolerant species included the native species Desmoschoenus spiralis and Scirpoides nodosa. Most tolerant exotic species were grasses; Elymusfarctus was the most salt tolerant species tested, and possibly in Barbour's 'facultative halophyte' category.Species scores from the first vegetation gradient ofan ordination of field data from four dune systems were plotted against results from this study. For some species, root-salinity tolerance correlated with their field position. However, there was little correlation with distributions on West Coast dunes, with some glycophytes growing in the senli-fixed dunes. This was attributable to the high rainfall. On the dry east coast, however, species were more tolerant and their distribution more closely linked to their salinity tolerance.New Zealand dunes contain a mixture of root-salinity tolerant species and root-salinity intolerant species. It is suggested that root-salinity is only one ofa complex of environmental factors important on dunes.

Effects of salinity on seed germination, seedling growth and survival of Spartina ciliata Brong

“…Coastal sand dunes, particularly in hot and dry areas, are subjected to salinities ranging from its absence, after a heavy rainfall, up to 500 mM NaCI, after a sea overwash (Sykes & Wilson 1989). In southern Brazilian coastal dunes a maximum of 80mM NaCI was found in interstitial soil solution during the dry season (Cordazzo 1985).…”

“…The effects of salinity on seed germination and plant growth have been studied for more than a century (Darwin 1857). Seed germination and seedling establishment under various salinities have been investigated in many halophytes (Ungar 1962(Ungar , 1974Bazzaz 1973;Woodell 1985), and particularly in some sand dune species (Seneca 1969;Sykes & Wilson 1989;Greipsson & Davy 1994,). However, Spartina ciliata, a perennial grass of southwestern Atlantic coastal sand dunes, has received no attention despite its wide-spread occurrence and importance.…”

Ecological impacts of the 2004 Indian Ocean tsunami on coastal sand-dune species on Phuket Island, Thailand

“…Kleijn (2003) suggests that early colonists determine successional pace and change. On the other hand, the proportions of relevés occupied by ephemeral non-coastal sand-dune species had Notations are defined as follows: B, 6 months before the tsunami; A1, 9 months after the tsunami; and A2, 7 years after the tsunami significantly decreased by period A2 compared with period A1 (Tables 1, 2), perhaps in response to constant coastal stresses such as sand movement, plant burial, drought, and salt winds (Sykes and Wilson 1989;Sykes and Wilson 1990;Wilson and Sykes 1999). The impacts on coastal species of non-coastal sand-dune species invading after the tsunami were therefore temporary and minimal.…”

An unusual climbing dune, Big Hellfire Pass, Stewart Island, New Zealand: exploration through environment, vegetation and trait patterns

“…Dune vegetation often experiences sand burial, wind blast, sea spray and salt deposition (Sykes & Wilson 1989, 1990a, 1990bUdo & Takewaka 2007;Ogura & Yura 2008). The effects of salt have been shown to be more important than burial for some dune species (JB Wilson & Sykes 1999), and where developed, soil characteristics are more important than other factors (Lane et al 2008), while sand blast appears to exacerbate the effects of salt spray (Ogura & Yura 2008).…”