Waterlogging affects the distribution of the saltmarsh plant Atriplex portulacoides (L.) Aellen

Atriplex portulacoides is a perennial halophyte common along northern European coasts. However it has been observed to be completely absent from peat based Ombrogenic Atlantic saltmarshes. The aim of this study was to elucidate the factors affecting the in situ distribution of A. portulacoides within saltmarsh sites including its absence on peat based saltmarshes. This was carried out through three approaches: by mapping the distribution of A. portulacoides within saltmarshes on the southwest coast of Ireland; by examining the ability of rooted cuttings of A. portulacoides to establish on peat and non-peat saltmarshes in situ; and finally by investigating experimentally the tolerance of A. portulacoides to waterlogging treatments. This study indicates that a combination of multiple abiotic and biotic factors, including intolerance to high soil moisture most likely determines the distribution of A. portulacoides.