Martinez-Abrain A.,CSIC - Mediterranean Institute for Advanced Studies |
Martinez-Abrain A.,University of California at Riverside |
Martinez-Abrain A.,University of La Coruña |
Tavecchia G.,CSIC - Mediterranean Institute for Advanced Studies |
And 4 more authors.
Journal of Applied Ecology | Year: 2012
Wind farms are emerging as a major cause of mortality of large scavenging bird species, which may be catastrophic when they operate in concert with other threats. As a study model, we examine the impact of wind turbines on the population dynamics of a soaring bird species, when acting in conjunction with a sudden decrease in food availability following the European bovine spongiform encephalopathy (BSE) epidemic. In Spain, vultures have been provided with supplementary food at traditional vulture restaurants for centuries. In 2006/2007, these feeding stations were closed as part of disease control measures. At the same time, wind farms were deployed within the vulture foraging range. We used capture-recapture data and direct observation to monitor the impacts of these changes on the vulture population. The number of breeding pairs decreased by c. 24%, adult survival by 30% and fecundity by 35%. However, the population recovered as soon as the perturbations ceased, the vulture restaurants were reopened, and the most problematic wind turbines were closed. Population recovery was faster than predicted by a retrospective stochastic population model. Our analyses indicate that fecundity and survival were influenced predominantly by wind turbines. Food scarcity promoted a shift in foraging behaviour that drove vultures to fly into the path of wind turbines as they sought out new food sources in a landfill site. Elasticity and sensitivity analyses of the population model showed that mortality of adult birds had a much greater effect on population declines than mortality of immature birds, whereas reduction in fecundity had negligible effects. The most likely explanation for the rapid recovery of the vulture population is that the observed decline in breeding pairs was not solely because of increased mortality. The decline probably included dispersal away from the area and a greater incidence of skipped breeding during the perturbation years. Subsequent immigration from large nearby populations was probably a factor in population recovery. Synthesis and applications. Where specific wind turbines are causing substantial mortality, their closure is an effective management response. For vulture populations dependent on supplemental feeding stations, the feeding sites should be relocated away from the most problematic wind turbines, or other anthropogenic sources of mortality, to prevent negative impacts. We recommend the establishment of scattered, low-value food sources to replicate historical conditions and to avoid the problems associated with high concentrations of individuals in one place. © 2011 The Authors. Journal of Applied Ecology © 2011 British Ecological Society.
Elorza M.S.,Gerencia Territorial Del Catastro |
Ortiz D.G.,Fundacion Oroiberico |
Deltoro V.,Conselleria de Medio Ambiente
Botanica Complutensis | Year: 2011
This paper is a continuation of previous ones focused on the alien flora of autonomous regions of Spain. Now, we examine the alien flora of Comunidad Valenciana, an autonomous region of the eastern Spain. The source of data was mainly literature references, complemented with authors' experience. We can stablish, by the results obtained, a regional catalogue of 663 alien vascular plants species, of which 23% are invasive and 51 taxa are transformers. A number of them are potentially dangerous for natural ecosystems, mainly wetlands and maritime dunes. Invasibility of Comunidad Valenciana by alien plants is higher compared with the close regions due to its mild temperatures and high human presure. Good practice in relation to policies, legislation and management relating to invasive alien species is occuring in Comunidad Valenciana, but it remains scattered in other autonomous regions of Spain.
Oro D.,CSIC - Mediterranean Institute for Advanced Studies |
Jimenez J.,Conselleria de Medio Ambiente |
Curco A.,Parc Natural del Delta de lEbre
PLoS ONE | Year: 2012
In recent centuries and above all over the last few decades, human activities have generated perturbations (from mild to very severe or catastrophes) that, when added to those of natural origin, constitute a global threat to biodiversity. Predicting the effects of anthropogenic perturbations on species and communities is a great scientific challenge given the complexity of ecosystems and the need for detailed population data from both before and after the perturbations. Here we present three cases of well-documented anthropogenic severe perturbations (different forms of habitat loss and deterioration influencing fertility and survival) that have affected three species of birds (a raptor, a scavenger and a waterbird) for which we possess long-term population time series. We tested whether the perturbations caused serious population decline or whether the study species were resilient, that is, its population dynamics were relatively unaffected. Two of the species did decline, although to a relatively small extent with no shift to a state of lower population numbers. Subsequently, these populations recovered rapidly and numbers reached similar levels to before the perturbations. Strikingly, in the third species a strong breakpoint took place towards greater population sizes, probably due to the colonization of new areas by recruits that were queuing at the destroyed habitat. Even though it is difficult to draw patterns of resilience from only three cases, the study species were all long-lived, social species with excellent dispersal and colonization abilities, capable of skipping reproduction and undergoing a phase of significant long-term population increase. The search for such patterns is crucial for optimizing the limited resources allocated to conservation and for predicting the future impact of planned anthropogenic activities on ecosystems. © 2012 Oro et al.
Guillen J.E.,Institute dEcologia Litoral |
Jimenez S.,Institute dEcologia Litoral |
Martinez J.,Institute dEcologia Litoral |
Trivino A.,Institute dEcologia Litoral |
And 3 more authors.
Thalassas | Year: 2010
The present study contains the results gathered from the programme monitoring the implantation of invasive species of algae in the Region of Valencia. The programme has been in operation since 1993 and consists of an annual inspection at 40 points considered to be at most risk along the coast, as well as responding to warnings given by entities and individuals. The programme was initially designed to detect the presence of Caulerpa taxifolia (Vahl) C.Agardh 1817, which has not been detected during any of the inspections carried out in the last 15 years. However, C. racemosa var. cylindracea (Sonder) Verlaque, Huisman & Boudouresque, 2003 was detected in 1999, more specifically on the approaches to the Port of Castellón de La Plana and since then it has expanded exponentially and is now present along the coast of all three Valencian provinces, with the area colonised being estimated at 168 Km2 in late 2008. The programme has also detected the presence of other invasive species of algae, namely Asparagopsis taxiformis (Delile) Trevisan de Saint- Léon, 1845 and Lophocladia lallemandii (Montagne) F. Schmitz, 1893, currently present exclusively in the Islas Columbretes archipelago.