Halofitismo en plantas de lacostacaribe de venezuela: halÓfitas ...






Las especies de COP tenían las mayores concentraciones de Na, y eran más suculentas (Sesuvium portulacastrum, S. edmondstonii, Batis maritima, Sarcocornia perennis y Heterostachys ritteriana). Chamaesyce mesembrianthemifolia y Croton punctatus tenían cocientes K/Na > 1 (no halófitas).

Chamaesyce mesembrianthemifolia, Scaevola plumieri, Argusia gnaphalodes, Egletes prostrata, Suriana maritima y Gomphrena albiflora son concentradoras relativas de K. Las especies calciófobas acumulan la mayor parte del Ca como oxalato insoluble (Atriplex oestophora, G.

Overview
Las especies calciófilas presentaron una fracción de Ca soluble en agua 50% (S. El δ13C reveló cinco especies con metabolismo fotosintético C4 (A. Los altos valores de δ15N sugieren como fuente principal de N al NO3 del suelo.

Este trabajo incluye una compilación de especies de plantas superiores de la costa caribeña de Venezuela con indicaciones sobre su carácter halofítico. Palabras clave: Costa Caribe, halófitas, isótopos estables, psamófitas, relación K/Na ABSTRACT To determine their degree of halophytism it was analyzed the mineral composition and stable isotopes (13C, and 15N) of leaf material and associated soils of 18 species of coastal plant species in three locations in Falcon State, Venezuela (Coro-La Vela road, COVE; east coast of Paraguaná, COP, and Tacuato bay in Paraguaná, TAC). COP soils were sandy and had the lowest concentrations of N, P, K and Na.

TAC soils showed higher salinity (Na, Mg and Ca), whereas those of COVE had higher N and P concentrations and clay texture. COP species had ISSN 0084-5906 Depósito Legal 196902DF68 50 Medina, Francisco, Wingfield y Casañas the highest Na concentrations and were more succulent (Sesuvium portulacastrum, S. edmondstonii, Batis maritima, Sarcocornia perennis and Heterostachys ritteriana).

Chamaesyce mesembrianthemifolia and Croton punctatus had leaf K/Na ratios > 1 (non halophytes). Chamaesyce mesembrianthemifolia, Scaevola plumieri, Argusia gnaphalodes, Egletes prostrata, Suriana maritima, and Gomphrena albiflora were relative K accumulators. Calciophobes accumulated most Ca in form of water insoluble oxalate (Atriplex oestophora, G.

albiflora and Alternanthera halimifolia), or sequestered in form of phosphates and pectates (Croton punctatus, S. Calciophile species had a water soluble Ca fraction ≥ 50% (S. The δ13C values revealed five species with C4-photosynthesis (A.

The positive values of δ15N suggest soil NO3 as the main N source. This paper includes a compilation of higher plant species of the Caribbean coast of Venezuela with indications of their halophytic character. Key words: Caribbean coast, halophytes, K/Na ratios, psammophytes, stable isotopes INTRODUCCIÓN La región costera litoral del mar Caribe se caracteriza por un clima marcadamente estacional, con precipitaciones menores de 1000 mm, temperaturas medias anuales superiores a los 25°C, y elevada carga radiacional.




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