Mediterranean landscapes and plant communities relationship

Abstract

Abstract. On the basis of an earlier landscape classification of Huelva (Andalusia, Spain) using the Twinspan multivariate classification method, which resulted in eight landscape types, the study sought to test the hypothesis that a relationship may exist between landscape types and plant communities. Samples of serial scrub communities were examined by stratified sampling between landscape types. Samples were classified using phytosociological and Twinspan methods. After merging landscape types and Twinspan-classified community types, the possible association between the two was analysed by means of a two-way contingency table between five landscape units and five plant communities. Findings enabled the null hypothesis, i.e. that both descriptors were independent, to be rejected. Given the high degree of overall agreement between phytosociological and multivariate plant community classifications, inter-community variation was studied via ecological characterization of the syntaxa identified. The results indicated that parent material played a more important role than climate-related variables in accounting for this variation. This conclusion supports the role assigned to each of the two factors in the biogeographical domain, according to the scale of the study. Keywords: Landscape characterization; Mediterranean scrub; Twinspan, phytosociology; Huelva (Andalusia).[es] Paisajes mediterráneos y su relación con las comunidades vegetales Resumen. A partir de la realización previa de una clasificación del paisaje de Huelva (Andalucía, España) mediante el uso del método multivariante de clasificación Twinspan, con la diferenciación de ocho tipos de paisaje, se ha planteado la hipótesis de la posible existencia de una relación tipos de paisajes-comunidades vegetales. El estudio se ha realizado a partir de comunidades de matorrales bajos, muestreados de forma estratificada entre los tipos de paisajes. Las muestras fueron clasificadas según la metodología fitosociológica y según el Twinspan. Después de un proceso de fusión entre tipos de paisajes, por una parte, y tipos de comunidades (según clasificación Twinspan) por otra, se ha procedido a un análisis de la posible asociación entre paisajes y comunidades. Este análisis, realizado mediante tabla de contingencia de doble vía entre cinco unidades de síntesis de paisajes y cinco de comunidades vegetales, ha permitido rechazar la hipótesis nula de que ambos descriptores fueran independientes. A partir de la buena correspondencia global entre la clasificación fitosociológica y la multivariante de las comunidades, se ha realizado un análisis de la variación entre comunidades en base a la caracterización ecológica de los sintaxones identificados. Del mismo se ha concluido el papel más determinante del material parental frente a variables climáticas, para explicar esta variación. Lo que concuerda con el papel atribuido a unas y otras en el ámbito biogeográfico, según la escala de estudio.

Secretory structures in plants: Lessons from the Plumbaginaceae on their origin, evolution and roles in stress tolerance

“…The Plumbaginaceae is well-known for salt and drought tolerance, with genera and species adapted to arid environments and a wide range of saline habitatsadaptations involving anatomy (e.g., multicellular glands) and physiology (e.g., osmoprotective compounds; Slama, Abdelly, Bouchereau, Flowers, & Savouré, 2015). In the Plumbaginaceae, salt glands occur in species that can grow in tidal areas (including the mangrove Aegilatis; Das, Mishra, & Mohanty, 2006) and in higher drier parts of salt marshes subjected to high salinity (e.g., Limonium and Limoniastrum; Alvarez & Manzanares, 2017;Costa et al, 2014;Dawson & Ingrouille, 1995;de Fraine, 1916;Zhao, Song, Feng, Zhao, & Liu, 2011). Glands are also present in genera that grow on rocky coasts in incipient soils exposed to deposition of airborne salt spray (as in Limonium, "rocky species"; Caperta et al, 2014) and in Armeria species of coastal sand dunes (Arseni & Diez-Garretas, 2017).…”

Secretory structures in the Plumbaginaceae: origin, evolution and roles in stress tolerance

“…osmoprotective compounds; Slama, Abdelly, Bouchereau, Flowers & Savoure, 2015). In the Plumbaginaceae, salt glands occur in species that can grow in tidal areas (including the mangrove Aegilatis ; Das, Mishra, & Mohanty, 2006) and in higher drier parts of salt marshes subjected to high salinity (e.g.,Limonium and Limoniastrum ; Alvarez & Manzanares, 2017;Costa et al, 2014;Dawson & Ingrouille, 1995;de Fraine, 1916;Zhao, Song, Feng, Zhao and Liu, 2011). Glands are also present in genera that grow on rocky coasts in incipient soils exposed to deposition of airborne salt spray (as in Limonium, 'rocky species'; Caperta et al, 2014) and in Armeria species of coastal sand dunes (Arseni & Diez-Garretas, 2017).…”