Response of Armeria maritima (Mill.) Willd. and Plantago maritima L. from an Irish salt marsh to nitrogen and salinity

Abstract

SUMMARYTwo experiments on the interaction between salinity and nitrogen supply were carried out on the halophytes Armeria maritima and Plantago maritima. Water potential values ranged from -016 MPa to -5-OMPa and nitrogen from 028 to 280 mg 1"' N. An increase in nitrogen above 2 8 mg T' N in the medium in all cases resulted in an increase in growth, though this was not so great at higher salinities. Armeria growth rate was optimal at a higher nitrogen concentration than Plantago and Armeria also accumulated nitrogen in shoots with increasing salinity. Plantago root nitrogen concentrations increased with increased nitrogen.Both species accumulated sodium in shoots, but in Armeria concentrations were lowest in the highest nitrogen treatments. Potassium was redistributed from shoots to roots with increasing salinity.Two populations oi Plantago from the salt marsh were examined. Differences in growth response and flowering time were observed. A third, inland population otPlatitago showed reduced vigour in water potentials lower than -2-5 MPa.

Salinity Tolerance, Ion Accumulation Potential and Osmotic Adjustment In Vitro and In Planta of Different Armeria maritima Accessions from a Dry Coastal Meadow

“…In Na-accumulating halophyte species, Na + is stored in vacuoles of mesophyll cells [ 51 ], and there is an experimental evidence that surplus K + is also stored in vacuoles, both regulating osmotic potential and acting as the main cellular reserve of K + [ 58 ]. Earlier it was shown that A. maritima plants from salt marsh redistributed K + from shoots to roots with increasing salinity [ 59 ], but no such response was found in the present study in spite of significant decrease of K + concentration in leaves ( Figure 7 ).…”

Vegetational response to human colonisation of the coastal and volcanic environments of Ketilsstaðir, southern Iceland

“…The expansion of Plantago maritima (sea plantain) follows a near identical pattern to that of P. lanceolata. It is a stress-tolerant species that thrives on nitrogen-rich soils (Sheehy Skeffington and Jeffrey, 1988) and at Lambi in the Faroe Islands the plant increases in abundance in association with cultivation from what appears to be the onset of the settlement period (Jóhansen, 1979). It seems likely, therefore, that this species could expand in both arable and pastoral situations.…”