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The European Red List is a review of the status of European species according to IUCN regional Red Listing guidelines. It identifies those species that are threatened with extinction at the regional level – in order that appropriate conservation action can be taken to improve their status. This publication summarises results for all Europe’s native species of tree (454 species), of which 265 species (over 58%) are endemic to continental Europe, with 56% (252 species) endemic to the 28 EU Member States. Of these, 168 (42%) of the species are threatened with extinction at the European level, however, for 57 species (nearly 13%) there was insufficient information to assign a conservation status, and are therefore classified as Data Deficient, and in need of further research. The main threat to tree species in Europe has been identified as invasive or problematic species, impacting 38% of tree species, followed by deforestation and wood harvesting, and urban development (both affecting 20% of tree species). For threatened species, livestock farming, land abandonment, changes in forest and woodland management, and other ecosystem modifications such as fire are the major threats, impacting the survival of trees.

Clonal reproduction of Azolla filiculoides Lam., an aquatic floating fern, native from the American subtropics and a recent invader of Mediterranean wetlands, was assessed experimentally. Shoot fragmentation of the species was quantified under suitable room conditions for optimum growth. Azolla fililculoides showed high longevity, a low mortality percentage and a high potential for clonal reproduction (biomass obtained by shoot fragmentation from only one individual was multiplied by 100). This last attribute changed over time: first generations developed a high number of propagules, a number which decreased progressively in later generations until the end of the experiment. The results of this experiment will be useful for understanding Azolla’s success within invaded habitats.

Mediterranean temporary ponds are a priority habitat under the European Union Habitats Directive, but those of natural origin are scarce, as many of them have been destroyed or transformed into permanent waters. The aim of this study is to highlight the conservation value of the system of temporary ponds in Doñana National Park, where more than 3000 water bodies may be filled during wet years. They are located on soils of aeolian origin where water persistence is favoured by the presence of an argilic semi permeable horizon and by a relic clay-rich sandy layer. Temporary ponds can be classified across a wide hydroperiod gradient. Most ponds fill with autumnal or winter rains and persist up to late spring or summer, and only a few may persist through summer. Eight of the 11 amphibian species of this area require temporary ponds for breeding. More than 124 taxa of macroinvertebrates have been recorded, coleopterans (56 taxa) and heteropterans (19 taxa) being the richest taxonomic groups. Several zooplankton species are endemic to this kind of habitats, such as the copepod Dussartius baeticus and the rotifer Lecane donyanensis. Regarding vegetation, at least 55 hydrophytes species were identified in the ponds sampled, and also some species endemic to SW Iberian Peninsula (Callitriche regis-jubae, Scorzonera fistulosa, Callitriche lusitanica) and others are in relic situation (Hydrocharis morsus-ranae, Thorella verticillato-inundata, Lemna trisulca). The conservation value of these ponds is highlighted by the large variety of protected and/or rare species of flora and fauna, which are favoured by a high pond abundance and connectivity. © Asociación Ibérica de Limnología, Madrid. Spain., This study was funded by the Spanish Ministry of Science and Education and EU FEDER funds (CGL2006-04458/BOS) and Junta de Andaluc ́Æa (Excellence Research Project RNM 932) and Fel- lowship grants CSIC-I3P (European Union So- cial Funds) to M.F. and AP-2001-3475 to C.G.-R. and JA-2003 to R.F.-Z., and JA-2005 to A.P.

13 páginas.-- 3 figuras.-- 4 tablas.-- 47 referencias, Geomorphological and hydrological features can provide a sound basis for global wetland classification. Temporary ponds located on the sandy area of Doñana can be classified into five different geomorphological areas. We hypothesised that these ponds would differ in soil characteristics, which may also explain differences in the composition of their macroinvertebrate, amphibian, and aquatic plant species assemblages. The study ponds were significantly segregated into southern and northern geomorphological areas based on the depth to the water table. The results of the multivariate ordination of soil variables were consistent with a north-south segregation, which was explained by the carbonate and other main ion concentrations in the pond basins. The ponds located in ecotones (marsh-sand and stable-mobile dunes) were particularly rich in amphibians and macroinvertebrates. This result may be explained because the ponds with the longest permanence of water were located in these areas, which represented the only flooded ponds during droughts. In addition, they also contained a high number of temporary ponds, thus favouring connectivity and environmental heterogeneity in these areas., This study was funded by the Spanish Ministry of Agriculture, Food and Environment (project 158/2010). We thank Isabel Afán and David Aragonés of LAST_EBD for the map drawing and the management personal of the Parque Nacional de Doñana and the Reserva Biológica de Doñana for their valuable help during our visits to the park.