Small-scale resource heterogeneity among halophytic plant species in an upper salt marsh community

The focus of the present study was to determine whether spatial and temporal variation, in soil and plant factors of upper salt marsh areas, exists among microsites of three coexisting halophytic plant species, Grindelia humilis, Jaumea carnosa and Limonium californicum, on the Pacific coasts of California. Low frequencies in tidal inundations coupled with variation in temperature and rainfall patterns often result in wide seasonal salinity variations in these upper salt marsh zones. The study was carried out to evaluate (1) variation in soil osmolalities and soil water contents for the three species; (2) differences in chemical soil factors associated with the three species; (3) variation in leaf succulence associated with saline stress; and (4) levels of plant nutrients present in each of the three species. The results indicated that soil osmolalities associated with Limonium, a salt excreting halophyte were markedly different from those recorded for the other two species. Nitrogen levels in soils associated with Jaumea as well as levels in composite plant samples were significantly lower than those of the other two species. Also noted were variations in nutrient ions in plants as well as soil environments. (C) 2004 Elsevier B.V. All rights reserved.