Elías D. Dana

Aproximación al listado de plantas alóctonas invasoras reales y potenciales en España

Gives the growing importance that invasions of alien plants are acquiring worldwide as a factor is environmental deterioration and loss of biodiversity, we present the checklist of invasive alien plants in Spain (Peninsula and Balearic Islands), similar to those already published in many other countries. The checklist is structured into two series covering plants with evident invasive behaviour (78 species) and those presenting invasive behaviour that is incipient or restricted to lowvalue ecosystems (currently90 species). By way of prevention, we also include the list of 56 species of invasive alien plants in northern Europe.

Urban vegetation of Almerı́a City—a contribution to urban ecology in Spain

In this paper, we analyzed the vegetation of the city of Almeria (southeast of Spain) using numerical methods. We distinguished 16 communities. Although most of them had an eminent ruderal character, some phytocoenoses were typical from non-disturbed environments. These communities can be distinguished not only by means of the dominant species, but also by the abundance of different biological forms. Thus, they can be grouped into six phytosociological classes. It was not found that diversity and coverage values were related to the features of the different habitats, but woody and herbaceous communities tended to occupy different types of biotopes. From the ecological point of view, the communities can be included into five groups, the floristic composition of which is related to the frequency of disturbance events as well as to the water availability of soils. According to the species composition and to the ecological significance of the communities detected, the city can be subdivided into three zones. These areas match the three historical phases of the city development. Finally, the possible implications of the results obtained are discussed in the context of urban planning and development, taking into consideration the conservation of valuable rare species and plant communities.

Plant succession in abandoned gypsum quarries in SE Spain

Gypsum outcrops harbour a considerable number of rare species the presence of which is restricted to these soils. By the rarity and richness of their flora, gypsum soils of Almer‡a Province (SE Spain) are the most valuable in Spain from a conservation view- point, whereas at the same time the territory is being intensively exploited by quarrying and holds the most important production of gypsum rocks in Europe. It was hence con- sidered a priority to investigate the recovery patterns of gypsophilous species after quar- ries abandonment in order to seek for information that can help to develop restoration plans with an ecological basis. For this aim, chronosequences were established and the colonising flora (presence and abundance) in each successional state was recorded and compared to the non-disturbed communities. Data were mainly analysed by means of Frequency Diagrams and Multivariate Methods. Dendrograms resulting from the Cluster Analyses showed the existence of two well-defined groups of species that differed in their colonisation power. One of the groups harboured Gypsophila struthium subsp. struthium, the dominant gypsophyte in the early states (in quarries abandoned up to 25 years ago), which coexists with other less abundant ruderal species. The other group was character- ised by the presence of the remaining gypsophytes such as the endemisms Teucrium turredanum or Helianthemum alypoides , which show a low colonisation ability and ap- pear in the last stages (mainly in quarries abandoned more than 30 35 years ago). Ordina- tion Analyses separated the samples taken from the unaltered scrub from the others, which indicates that although there is a clear tendency towards the recovery of gypsum soils by the gypsophytes of the area, the primary succession does not lead to the re- establishment of the relative abundances of all the original species in the interval of time considered.

Aproximación al listado de plantas vasculares alóctonas invasoras reales y potenciales en las islas Canarias

Sobre la base de la importancia adquirida a escala mundial por las invasiones de plantas vasculares aloctonas en las estrategias de conservacion de la biodiversidad, se presenta la lista preliminar de especies vegetales exoticas invasoras en las islas Canarias, de manera analoga a la ya publicada en esta misma revista para los territorios peninsulares e islas Baleares. La presente lista ha sido estructurada en tres partes. La primera incluye aquellos taxones con claro comportamiento invasor (47 especies), la segunda alcanza a aquellos con comportamiento invasor incipiente (68 especies) y la tercera se refiere a taxones invasores en otras regiones insulares con condiciones ambientales parecidas, algunos de ellos incluso presentes ya en Canarias, que podrian resultar potencialmente peligrosos (37 especies).

Vegetation Response after Removal of the Invasive Carpobrotus Hybrid Complex in Andalucía, Spain

We evaluated the ecological success of the manual removal of Carpobrotus species, a putative hybrid complex of a South African perennial mat-forming plant, by comparing treated, noninvaded, and invaded plots across coastal Andalucía in southern Spain. As a measure of the management effectiveness, we quantified the density of Carpobrotus seedlings and resprouts in treated plots one year after treatment. Response of the plant community to removal was assessed by comparing native species richness, cover, diversity, and species composition among treatments. Removal greatly reduced to a great extent Carpobrotus density. However, successful control will require repeated hand-pulling treatments. Treated plots had a significant increase in species richness, especially annual plants, compared to invaded plots, but both had the same native plant cover and diversity. We found similar species composition between removal and noninvaded plots, indicating that revegetation is not necessary. Long-term monitoring is necessary to determine whether these observed patterns of community response are transient or stable through succession.

Selección de áreas prioritarias para la conservación de flora gipsícola en el sureste de la Península Ibérica

Recent studies have highlighted the gypsum outcrops of Almeria (southeast Spain) as the most outstanding for the conservation of Iberian gypsophilous flora. The need of preserving this natural heritage and the impossibility to protect all the outcrops present within the territory, led us to identify which areas should be considered as of priority for conservation. To this end, we establish as a priority that the proposed conservation network of sites should include all gypsophyte species at least once. Other possible conservation goals on which to base the area selection and the associated scenarios were also taken into account. We first elaborated a cartography for the gypsophytes based on 10 km sided-cells. Next, in order to rank the importance of each locality, several commonly employed conservation criteria (diversity, rarity of the flora, complementarity) were applied to the cartographic information, and the findings obtained by each procedure contrasted. The results showed that protecting the deposits found in three cells (Sorbas, already protected because of its geomorphological singularity, Venta de los Yesos and Topares) would allow the representation of each species at least once and to achieve several complementary conservation targets. The findings are discussed within the context of the social and administrative peculiarities of the area.

Decision tools for managing biological invasions: existing biases and future needs

The increasing number of invasive species and their effects on wildlife conservation, together with a lack of public resources, make it necessary to prioritize manage- ment actions. In practice, management decisions are often reached on the basis of subjective reasoning rather than scientific evidence. To develop a more evidence-based and efficient management of biological invasions, decision tools (e.g. multi-criteria frameworks) that help managers prior- itize actions most efficiently are key. In this paper we review to what degree such decision tools are currently available. We used a literature search to identify relevant studies. Our analysis indicates that available studies are largely biased towards risk analysis and that only a few authors have pro- posed cost-benefit or multi-criteria frameworks for decision making. Until now, these frameworks have only been applied at limited regional scales but they could be applied more widely. Our review also shows critical biases in the geographical focus, habitats, and taxonomic groups of avail- able studies. Most studies have focused on Europe, North America or Australia; other continents have largely been ignored. The majority of studies have focused on terrestrial plants; other habitats and taxonomic groups have been poorly covered. Most studies have focused on a single invasive species but practical management tools should consider a wide variety of invaders. We conclude with suggestions for developing improved decision tools.

Baccharis spicata (Asteraceae), a new potentially invasive species to Europe

Abstract Baccharis spicata, a species native to South America (southern Brazil, Paraguay, Uruguay, and northeastern and central Argentina) is reported for the first time from Europe. In September 2015, two naturalized populations were detected in the surroundings of Porto (Matosinhos and Vila do Conde) in Portugal. Based on literature data, the species’ taxonomy and nomenclature are analyzed and it is described and illustrated. Furthermore, its ecology, habitat, biology, and possible vector of introduction are discussed. Finally, its invasive potential for the European Union is assessed, based on climatic variables and two different risk assessment methods.

Alien Plants and their Influence on Vegetation

There is a high level of plant invasion in the Iberian Peninsula and Balearic Islands. Some of the contributing factors for this are the geographical, climatic and historical characteristics of these territories. The latest estimate of the number of naturalised alien taxa is 17.9% for Portugal and 11% for Spain. A list of 51 major invasive plants on the Iberian Peninsula and Balearic Islands with information about the main invaded habitats and the correspondence with the syntaxa is presented in this chapter. The number of invasions increases greatly every year, as a result of insufficient control measures from the respective authorities, a lack of commitment from the business sector involved and nearly nil public knowledge of the problem. The ecosystems globally most at risk of invasion are wetlands and coastal and riparian habitats. Coastal habitats house many endangered species and plant communities and numerous management strategies focus on them. Wetlands and rivers offer some of the most dramatic examples of displacement of native species and ecosystem disruption by, for example, Azolla filiculoides and Eichhornia crassipes, two of the main aquatic invasive species in the world. In order to highlight the importance of the control of invasive species in endangered habitats, we have chosen two study cases: Baccharis halimifolia, in the estuaries of northern Spain and Carpobrotus edulis in Mediterranean and Atlantic coastal communities.