Abstract

AVENDANO, Yamilex et al. Spatial patterns in a halophyte grassland: soils, plant communities and phenotypic plasticity of Sporobolus virginicus (L.) Kunth, Révis. Gramin. 1: 67 (1829) in Miranda state, Venezuela. Biota colombiana [online]. 2018, vol.19, n.1, pp.21-38. ISSN 0124-5376.  https://doi.org/10.21068/c2018.v19n01a02.

The relationship between soil and vegetation was studied in a salt marsh dominated by Sporobolus virginicus (L.) Kunth (Poaceae). We used 42 sampling units placed on a 66 m long transect; in each soil sample we measured the bulk density (g/cm³), organic matter (%), inorganic carbon (%), pH, texture, soil salinity (‰) and interstitial salinity (‰). Also, the relative cover of each species (%), total vegetation cover (%), total biomass of the vegetation (g/m²), and the relative composition (%) of each species was measured. The community consisted of 7 species and was dominated by 2 S. virginicus morphotypes: a large morphotype (probably virginicus variety) was associated with soils characterized by higher pH, higher bulk density, lower salinity and lower organic matter (%), in comparison with the small morphotype (probably minor L. M. Bailey variety). The pH, organic matter, salinity and bulk density determined significantly (p<0.001) 26% of explained variance of this community. The transect showed three zones with different edaphic characteristics and different herbaceous communities; nevertheless, those communities had some common species. The water dynamic of the soil may respond to small topographic variations, which could in turn determine differences on local flood and evaporation processes.

Keywords : Herbaceous halophytes; Hydric soils; Miranda state; Wetlands.

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