Dittrichia viscosa is a Mediterranean ruderal species that over the last decades has expanded into new habitats, including coastal salt marshes, ecosystems that are per se fragile and threatened by human activities. To assess the potential risk that this native-invasive species represents for the genuine salt marsh vegetation, we compared its distribution with that of Inula crithmoides, a taxonomically related halophyte, in three salt marshes located in ‘La Albufera’ Natural Park, near the city of Valencia (East Spain). The presence of D. viscosa was restricted to areas of low and moderate salinity, while I. crithmoides was also present in the most saline zones of the salt marshes. Analyses of the responses of the two species to salt and water stress treatments in controlled experiments revealed that both activate the same physiological stress tolerance mechanisms, based essentially on the transport of toxic ions to the leaves – where they are presumably compartmentalized in vacuoles – and the accumulation of specific osmolytes for osmotic adjustment. The two species differ in the efficiency of those mechanisms: salt-induced increases in Na+ and Cl- contents were higher in I. crithmoides than in D. viscosa, and the osmolytes (especially glycine betaine, but also arabinose, fructose and glucose) accumulated at higher levels in the former species. This explains the (slightly) higher stress tolerance of I. crithmoides, as compared to D. viscosa, established from growth inhibition measurements and their distribution in nature. The possible activation of K+ transport to the leaves under high salinity conditions may also contribute to salt tolerance in I. crithmoides. Oxidative stress level – estimated from malondialdehyde accumulation – was higher in the less tolerant D. viscosa, which consequently activated antioxidant responses as a defense mechanism against stress; these responses were weaker or absent in the more tolerant I. crithmoides. Based on these results, we concluded that although D. viscosa cannot directly compete with true halophytes in highly saline environments, it is nevertheless quite stress tolerant and therefore represents a threat for the vegetation located on the salt marshes borders, where several endemic and threatened species are found in the area of study

Alien plants colonization, due to the fast spreading of highly invasive taxa, is more and more a serious source of concerns for habitat and species conservation. Apart direct in situ intervention, it is of major importance to acquire the best and up to date knowledge about alien taxa that currently threaten the integrity of wild and valuable environments. In this light, here is presented the update to the checklist of alien vascular flora of the island of Sardinia (Italy) on the basis of the new findings, nomenclatural adjustments, and revision of diffusion status of alien taxa. The checklist at present, consists of 541 taxa (84 doubtful) which represent 17% of the whole flora of the island; 22 taxa are new to the island and 7 of them for Italy. Neophytes represent the majority of the whole alien flora (301, 66% of the total) and, in confront to archaeophytes, gather nearly all invasive taxa (54 vs 4). The new findings are all neophytes. Phanerophytes (42%) are the most representative biological form and Americas represents the region that mostly contributes to the Sardinian alien flora (33%). Further analysis highlights that, in terms of number of taxa, highly anthropically impacted environments such as synanthropic (36%) and agricultural (23%) are the eligible habitats for most of the alien species in Sardinia while coastal areas and wetlands, beyond hosting a lower number of taxa, are characterized by the relative highest number of invasives.

Esta investigación se enmarca en la formación del profesorado en el Máster Universitario en Profesorado de Educación Secundaria. Se muestran resultados de un análisis de las guías docentes de asignaturas de las especialidades de Biología y Geología y de Física y Química del Máster con el fin de examinar en qué medida está presente la educación para la sostenibilidad (EpS). Así mismo se aborda la formación de equipos colaborativos del profesorado para favorecer la adquisición de competencias en sostenibilidad y en EpS entre las metas formativas de sus proyectos docentes y que arbitren los medios, recursos y procedimientos para su consecución eficaz. Se proponen aportaciones fundamentadas que traten de impulsar la atención a la EpS en la formación del profesorado de Secundaria.

This article provides a comparison of the vascular alien flora of Sardinia (Italy) and that of Corsica (France), both territories belonging to the Western Mediterranean biogeographic subregion. The study has recorded 598 (90 doubtful) alien taxa in Sardinia (18% of the total flora) while 553 (87 doubtful) in Corsica (17%); six are new report to Sardinia and 27 to Corsica. A total of 234 taxa are common to both islands. Neophytes are 344 taxa (68% of the total) in Sardinia and 399 taxa (73%) in Corsica. The invasive component includes 64 taxa in Sardinia (13% of the alien flora) and 99 taxa (21%) in Corsica, 33 of them common to both territories. The total 740 alien taxa of Sardinia and Corsica are included in 93 families; being Fabaceae the richest. The comparison of the biological spectrum reveals that phanerophytes (202 taxa, 40%) are the most represented in Sardinia and therophytes (149 taxa, 32%) in Corsica. A study of the geographical origin shows supremacy of the American element in Sardinia (170 taxa, 34%) and in Corsica (136 taxa, 29%). The majority of taxa arrived as a result of intentional human introductions, mainly for ornamental use (247 taxa, 49% in Sardinia; 208 taxa, 45% in Corsica). Semi-natural, agricultural and synanthropic are the most occupied habitats. These data show the need for joint action to stem the increasingly worrying phenomenon of the alien flora in order to reduce the negative effects on natural habitats and native flora.