Effects of sandblasting and salt spray on inland plants transplanted to coastal sand dunes

A transplant experiment was conducted on a sandy beach to elucidate whether salt spray and sandblasting are the major factors inhibiting inland plants from becoming established on coastal sand dunes. Potted inland plants of Miscanthus sinensis and Imperata cylindrica var. koenigii were transplanted in two zones on the beach and in one area far inland from the beach. One zone on the beach (sea side) was located on a front dune that was occupied by native sand-dune plants; the other zone (land side) was located behind the sand dunes, where grassland comprised both sand-dune and inland species. To assess the condition of transplants, we measured changes in the canopy leaf area periodically at all sites. The final dry weight at each site was determined at the end of the experiment. Seasonal changes in sandblasting and salt spray intensities were evaluated periodically at the sites by measurement of the opaqueness of exposed transparent plastic sheets and the amount of sodium trapped in exposed filter papers, respectively. All transplants died in the sea-side zone, where both salt spray and sandblasting were most frequent and intense. The final dry weight was greatest at the inland site, which lacked salt spray and sandblasting. Although salt spray was intense in the land-side zone, the canopy leaf area decreased considerably only in seasons during which salt spray was accompanied by intense sandblasting. We concluded that sandblasting accompanied by salt spray is one of the main factors inhibiting the survival and growth of inland plants on coastal sand dunes.