Mesembryanthemum crystallinum and M. nodiflorum are salt accumulators. After plant death, the salt leaches from the decaying plant into the surrounding soil. This increased salinity stops other, less salt-tolerant species from establishing. More information is available on salt accumulation by M. crystallinum than for M. nodiflorum, but it is assumed that the mechanisms and ecosystem results are similar for both species.

El-Ghareeb 1991
Kloot 1983
Vivrette and Muller 1977

Causes oxalate poisoning in sheep. Ice plant was a primary food item for island foxes (>10% frequency of occurrence in scats) during two seasons on San Clemente, three seasons on San Miguel and all four seasons on San Nicolas. Although these plants are providing a benefit to foxes by increasing the diversity of available food items, these plants also may be excluding native species. Reducing or eliminating these non-native plants probably could be conducted without adverse impacts to foxes, with the exception of San Nicolas. On this island, foxes may be at least partially dependent on these species and any reductions should be conducted gradually and preferably in conjunction with active restoration of native species to provide alternate foods for foxes (Cypher 2010).

Knapp and Garoutte (2016) found a strong negative impact of Mesembryanthemum crystallinum on native plant diversity and (related) arthropod diversity at two of three study sites on San Nicolas Island.

Cypher 2010
Halvorson 1992 in Stone 1992
Jacob and Peet 1989
Knapp and Garoutte 2016

M. chrystallinum needs open disturbed areas for establishment and does not grow well in intact grassland. It is assumed that M. nodiflorum has similar requirements.

Vivrette and Muller 1977

In the south coastal region this species has been present for a century or more with numerous collections and records over that period. During this period it has colonized much or most of the suitable habitat (saline coastal bluff and bluff scrub on packed, exposed soils). At its current level of establishment I suggest, at least in this region, that it may be difficult to assess its rate of spread, since it has already filled much of the suitable habitat (Vanderhoff, pers. comm. Knapp, J. pers. comm.). On the Channel Islands it is stable and has reached its distribution (J. Knapp, pers. comm.). Sayers reports seeing more in San Luis Obispo area recently.

Knapp, J. Personal communication.
Sayers, J. Personal communication.
Vanderhoff, R. Personal communication.

M. crystallinum is used for landscaping by Caltrans and by gardeners and can invade areas disturbed by grazing. M. crystallinum, and it is assumed M. nodiflorum, are able to invade disturbed areas created by human activities. M. nodiflorum is not commonly available horticulturally, but seeds are available on-line.

Randall 2000
Vivrette and Muller 1977

M. nodiflorum is native to South Africa. Other regions invaded are in Oregon, Arizona, Mexico, Europe and southern Australia.

In Australia, Mesembryanthemum crystallinum and M. nodiflorum are found on wide range of soil types, from well-drained sandy soils (including sand dunes), to loams and clays. They prefer acid, neutral or alkaline soils, but can tolerate nutritionally poor or saline soils. They occur in a range of vegetation communities, including saltmarsh, samphire flats eucalypt woodlands and shrublands, and as with many introduced species, also grow in disturbed sites such as roadsides, rubbish dumps and homestead yards. In California, M. nodiflorum is found in coastal bluffs, salty flats in the interior of the coastal slopes, and saline wetland margins, areas which are similar to those invaded in Australia and elsewhere. The Pacific Islands in Mexico within the California Floristic Province is invaded in the same habitat types as the Channel Islands (Knapp, J. pers. comm.).

DiTomaso and Healy 2007
Australia CSIRO 2004
Knapp, J. Personal communication.

In California, M. nodiflorum is found in coastal bluffs, salty flats in the interior of the coastal slopes, and saline wetland margins. It occurs in coastal, inland and desert habitats from San Diego north to the San Francisco Bay Area, with one outlying population in Glenn County. The first herbarium specimen in California was collected in 1882 in San Diego. Based on specimens in CCH, appears to have first been introduced along the coast and on the Channel Islands, then spread inland along roads in the 1960s and 70s, and began being collected inland in the 1990s. In inland Southern California its around in the usual low alkaline places, in western Riverside County. Populations are scattered and typically not terribly large, but can be locally fairly common. Its in the Perris Basin and on the alkaline flats west of Hemet mostly, but some in the Elsinore-Temescal area. In open sites, seasonally wet, fine alkaline clay soils (Sanders, pers. comm). Also observed around Lake Elsinore in semi-saline soils of the dry lakebed, and along the outlet drainage down into Temescal Canyon (Boyd, pers. comm.). Also seen along riparian corridors along the Santa Clara River in Ventura County (Fraga, pers. comm.). Invades the Pacific Islands in Mexico within the California Floristic Province (Knapp, J. pers. comm.).

DiTomaso and Healy 2007
CCH 1882
Calflora 2016
Boyd, S. Personal communication.
Fraga, N. Personal communication.
Knapp, J. Personal communication.
Sanders, A. Personal communication.