Francisco Robledano

Effects of climatic change on the distribution and conservation of Mediterranean forests: the case of Tetraclinis articulata in the Iberian Peninsula

South-eastern Spain is a key area for assessing the effects of climatic change on Mediterranean biodiversity since it represents an ecotone between the Mediterranean macrobioclimate and a vegetation with subtropical components. It also maintains many restricted-distribution species such as forests of Tetraclinis articulata, which with the exception of Malta, only is found here in Europe. The likely response of the species under B2 and A2 climatic scenarios is studied, using the species distribution model (SDM) and a high-resolution regional climate model (RCM). The results point to a marked increase in potential habitat under the B2 scenario, including a shift toward higher altitude and latitude values. Under the A2 scenario a substantial reduction in potential habitat is to be expected, accompanied by a drastic change in its geographical distribution, with the emergence of a new suitable area in the mountains of the interior and the total loss of the species’ present coastal habitat. Under the B2 scenario the network of reserves seems to be adequate since this would provide a substantial increase in the protected habitat, the present and future potential habitats partially overlap and most of the reserves are sufficiently close to allow the migration of the species by means of short-distance dispersal mechanisms. Under the A2 scenario, two existing reserves in the interior would be suitable, although the probability of natural migration is low due to the low dispersal capability of the species and the absence of overlapping areas between the present and future potential distribution areas.

The effect of age and sex on wing morphology and body size of the Bearded Tit Panurus biarmicus in relation to complete moult

In sedentary birds, variation in wing morphology as a result of complete moult during the transition from juvenile to adult plumage is poorly understood. The aim of this study was to characterise sex‐ and age‐related differences in wing morphology resulting from a complete post‐juvenile moult in an isolated, sedentary population of the Bearded Tit Panurus biarmicus at El Hondo Natural Park reedbeds (SE Spain). Variation in wing morphology was evaluated by means of a Size‐Constrained Components Analysis (SCCA) of standardised primary lengths of 66 birds trapped for ringing. Wing traits representing size and shape showed differences among age and sex classes, adults having significantly greater wing sizes than juveniles and males less rounded or convex wings than females. Structural body size also varied significantly among sex classes, females being smaller than males. Sex‐ and age‐specific differences in wing morphology of these Bearded Tits may represent adaptations to the sedentary and colonial behaviour of the local population within constraints imposed by a reedbed microhabitat.

Trade-Offs Between Biodiversity Conservation and Nutrients Removal in Wetlands of Arid Intensive Agricultural Basins: The Mar Menor Case, Spain

Abstract Some ecosystem services (nutrient removal and biodiversity conservation) in the wetlands surrounding the Mar Menor (southeastern Spain), the largest coastal lagoon in the western Mediterranean, have been assessed. A dynamic system model was developed to estimate the dynamics of nutrients, the role of wetlands in nutrient removal, and the final inputs reaching the lagoon. The socioeconomic issues, such as land use changes and seasonal dynamics of the tourist population, are part of the variables defining the model. The model tracks the increase in irrigated lands and the associated increased nutrient inflows, causing the eutrophication of the lagoon and favoring summer jellyfish outbreaks. The model was applied to test several management options to reduce the point and diffuse pollution and showed that the use of the Mar Menor wetlands would be the measure achieving the highest nutrient removal. A cost-effective analysis (CEA) has shown that this is also the most cost-effective of tested measures. The dynamic model and the CEA analysis have allowed a first economic valuation of some of the avoided costs of this ecosystem service. However, particularly in arid environments, there may exist a trade-off between the nutrient removal functionality of wetlands and the preservation of their biodiversity, dependent on high salinity and scarce flows of water and nutrients. This demands adequate and cost-effective solutions that acknowledge such trade-off. One option is to spatially differentiate both functions by keeping present wetlands without additional flows and by restoring previously lost areas of wetland for such nutrient removal service.

Consumption of honey bees by Merops apiaster Linnaeus, 1758 (Aves: Meropidae) in Mediterranean semiarid landscapes: a threat to beekeeping?

The diet of several European bee-eater Merops apiaster colonies was studied in the Murcia Region (SE Spain) during the spring and summer of 2009, in order to assess their predation on the honey bee Apis mellifera. The examination of invertebrate remains found in pellets revealed the dominance of Hymenoptera and Coleoptera in the average diet, and a similar consumption of honey bees compared to other species of Hymenoptera. The number of honey bees and other Hymenoptera recorded in the pellets varied both spatially (between locations) and temporally (along the main reproductive phases). On average, it was estimated that a single bee-eater consumed 1333.39 ± 759.8 honey bees during its complete stay in the region, far below the theoretical regeneration capacity of a single honey bee colony (36,000–45,000 honey bees per month from April to July). Consequently, under normal circumstances the effect of bee-eater predation on local apiaries appears negligible, and partially dependent on the availability of alternative prey.

Ecological and genetic consequences of fragmentation in a semiarid Mediterranean urban forest

Urbanization threatens biodiversity worldwide and is expected to increase in the future. This involves intensification of fragmentation and increase of urban forest remnants. Thus, it is important to understand the functioning of these patches for the preservation of local biodiversity. Mutualistic interactions such as seed dispersal have a key role in the dynamics of plant populations and could help to mitigate the negative effects of fragmentation on wild plant populations. In this context, we have used the mastic Pistacia lentiscus, a common Mediterranean shrub, as a model to study the interaction between seed dispersal by birds and the local genetic diversity of individuals in a highly fragmented semiarid forestry area of the Iberian Southeast (Murcia, Spain). Results reveal a high genetic diversity and a lack of differentiation between shrub patches of P. lentiscus in the area, probably as a result of a strong, but rather recent fragmentation, and an apparently poor contribution of birds to the dispersal of Pistacia seeds. However, the existence of latent impacts cannot be discarded, since at least one of the patches shows some signs of inbreeding.