Rosa Romero Franco

Sesquiterpene Lactones in Arnica montana: Helenalin and Dihydrohelenalin Chemotypes in Spain

An analytical RPLC method for sesquiterpene lactones in Arnica montana has been extended to include quantitative analyses of dihydrohelenalin esters. LC-ESI-MS-MS distinguished the isomeric helenalin and dihydrohelenalin esters. The dihydrohelenalin esters have lower response factors for UV detection than do helenalin esters, which must be taken into account for quantitative analyses. Analyses of flowers from 16 different wild populations of A. montana in Spain showed differing proportions of helenalin and dihydrohelenalin esters. For the first time a chemotype with high levels of helenalin esters (total helenalins 5.2-10.3 mg/g dry weight) is reported in Spanish A. montana. These samples were from heath lands at high altitude (1330-1460 m), whereas samples from meadows and peat bogs at lower altitudes were the expected chemotype with high levels of dihydrohelenalin esters (total dihydrohelenalins 10.9-18.2 mg/g). The phenolic compounds, both flavonoid glycosides and caffeoylquinic acids, in Spanish A. montana are reported for the first time. The levels of several of these compounds differed significantly between samples from heath lands and samples from peat bogs or meadows, with the heath land samples being most similar to central European A. montana in their phenolic composition.

Caracterización ecológica y florística de las comunidades lauroides del occidente de la Cornisa Cantábrica (Noroeste ibérico)

Mediante la comparacion de los inventarios floristicos obtenidos en los territorios Galaico-Asturianos occidentales (Sector Galaico-Asturiano, Subprovincia Cantabro-Atlantica, Provincia Atlantica Europea) con los de las asociaciones vegetales previamente descritas en el ambito cantabro-atlantico iberico, se establece la presencia en el extremo occidental de la Cornisa Cantabrica de cuatro asociaciones vegetales dominadas por especies lauroides ( Laurus nobilis, Arbutus unedo, Rhamnus alaternus ): lauredales costeros ( Calluno vulgaris-Lauretum nobilis ), lauredales interiores calcicolas ( Tamo communis-Lauretum nobilis ), lauredales interiores silicicolas ( Holco mollis-Lauretum nobilis ), y madronales ( Frangulo alni-Arbutetum unedonis ), asi como fragmentos de otra comunidad silicicola dominada por Rhamnus alaternus . Finalmente se realizan diversos comentarios sobre el significado biogeografico, valor paleoambiental e interes para la conservacion de las comunidades vegetales aqui tratadas.

Revisión de la sintaxonomía de los hayedos del occidente de la Cordillera Cantábrica (Noroeste Ibérico) mediante análisis multivariante

Se realiza una revision de la sintaxonomia de los hayedos existentes en el extremo occidental de la Cordillera Cantabrica (NW Iberico) basada en la ordenacion obtenida al aplicar un analisis NMDS a un conjunto de 47 inventarios floristicos. Los principales factores ambientales que explican la ordenacion obtenida son el pH del horizonte edafico superficial y la altitud. La interpretacion fitosociologica de las tendencias ecologicas observadas sustentan la existencia de dos tipos de hayedos en el area de estudio: acidofilos, incluibles en la asociacion Omphalodo nitidae-Fagetum sylvaticae , y neutro-basofilos asentados sobre suelos derivados de rocas carbonatadas pertenecientes a una nueva asociacion: Neottio nidi-avis-Fagetum sylvaticae . Sobre esta ultima comunidad se realizan consideraciones acerca de sus similitudes y diferencias floristicas y sucesionales con otros hayedos neutro-basofilos cantabricos asi como su ubicacion en el esquema sintaxonomico vigente.

Phytosociological framework and conservation value of supratemperate riparian birch forest of the NW Iberian Peninsula.

We studied the downy birch forests that grow in the headwaters of rivers in the mountains in NW Iberian Peninsula and their differences from other previously described birch forests. To do this, an ordination analysis was done on a data base of 342 releves (144 unpublished). As a result, four riparian forest associations were recognized in the territory, all of them belonging to the suballiance Saxifrago spathularis-Fraxinenion excelsioris (all. Hyperico androsaemi-Alnion glutinosae , ord. Alno-Fraxinetalia excelsioris , cl. Salici-Populetea ). Two associations ( Carici reuterianae-Betuletum celtibericae and Violo palustris-Betuletum pubescentis ) have been previously described, but the other two ( Chaerophyllo hirsuti-Betuletum pubescentis and Valeriano officinalis-Betuletum pubescentis ) are described here for the first time. We characterized their floristic composition, ecological features and distribution, and evaluated their conservation value under the criteria of the 92/43/CEE Community Directive, and with regard to national and regional lists of protected species.