13 research outputs found
El enmendador de corazones
Primer premio del Certame
Influencia local y paisajística sobre la riqueza de especies de anfibios que se reproducen en charcas temporales del litoral sud‐atlántico español. Determinación de impactos
The increase in urban land and the continuous increment of road network experienced by littoral
zones contribute to the loss, degradation and isolation of both terrestrial and aquatic habitats in
which amphibians spend the different stages of their life cycle. The aim of this study is to explain
the relationship between the characteristics of 17 seasonal ponds located in the Atlantic littoral of
Cádiz province (SW Spain), the land uses in their surroundings, the road network, and the diversity
of amphibian species. Our results show that amphibian richness is higher in larger ponds with
longer hydroperiods, surrounded by forest and scrubland, and away from the nearest road. Roads,
and in particular secondary roads, have a great and negative impact on amphibian richness because
the shorter the distance between the pond and the road was, the fewer breeding species
were found. From the data obtained in this study, we have classified the ponds according to their
status of conservation. This classification demonstrates that 94% of the studied ponds require immediate
measures to be taken in order to reduce the negative impact of habitat fragmentation
caused by roads. Finally, in order to maintain healthy amphibian populations at the long term,
forests and scrublands surrounding ponds must be protected, and connectivity among ponds, as
well as with the terrestrial habitats in the vicinity, must be ensured. Preventing amphibians from
road kills during their migration movements can be achieved by means of constructing underpasses
and tunnels in hot spots.La proliferación
de zonas urbanizadas y la expansión de la red de carreteras en zonas costeras contribuyen a
la pérdida, degradación y aislamiento de los hábitats tanto terrestres como acuáticos utilizados por
los anfibios en las diferentes fases de su ciclo vital. El objetivo de este estudio es explicar la relación
entre las características de 17 charcas temporales ubicadas en el litoral atlántico de la provincia de
Cádiz (SO de España), los usos del suelo en su entorno, la red de carreteras y la diversidad de especies
de anfibios. Nuestros resultados muestran que la riqueza de anfibios es mayor en charcas
más grandes y con hidroperiodos más prolongados, rodeadas de zonas forestales y de matorral, y
alejadas de las carreteras. Las carreteras, en particular las secundarias, tienen un fuerte impacto negativo sobre la riqueza de anfibios, como muestra el hecho de que cuanto menor es la distancia
entre la charca y la carretera, menor es el número de especies de anfibios presentes. A partir de los
datos obtenidos, clasificamos las charcas de acuerdo a su estado de conservación. Esta clasificación
demuestra que el 94% de las charcas estudiadas requiere la toma inmediata de medidas con el fin
de reducir el impacto negativo de la fragmentación del hábitat causada por las carreteras. Por último,
para mantener poblaciones de anfibios saludables a largo plazo, es preciso proteger los bosques
y zonas de matorral del entorno de las charcas, así como la conectividad entre charcas y con
el medio terrestre cercano. La construcción de túneles y pasos subterráneos en puntos negros de
atropello puede servir para prevenir la mortalidad de anfibios en las carreterasPeer reviewe
Reaction norms for metamorphic traits in natterjack toads to larval density and pond duration
The evolution of environmentally-induced changes in phenotype or reaction norm implies both the existence at some time of genetic variation within a population for that plasticity measured by the presence of genotype x environment interaction (G x E), and that phenotypic variation affects fitness. Otherwise, the genetic structure of polygenic traits may restrict the evolution of the reaction norm by the lack of independent evolution of a given trait in different environments or by genetic trade-offs with other traits that affect fitness. In this paper, we analyze the existence of G x E in metamorphic traits to two environmental factors, larval density and pond duration in a factorial experiment with Bufo calamita tadpoles in semi-natural conditions and in the laboratory. Results showed no plastic temporal response in metamorphosis to pond durability at low larval density. The rank of genotypes did not change across different hydroperiods, implying a high genetic correlation that may constrain the evolution of the reaction norm. At high larval density a significant G x E interaction was found, suggesting the potential for the evolution of the reaction norm. A sibship (1) attained the presumed 'optimal' reaction norm by accelerating developmental rate in short duration ponds and delaying it in longer ponds. This could be translated in fitness by an increment in metamorphic survival and size at metamorphosis in short and long ponds respectively with respect to non-plastic sibships. However, genetic variability for plasticity suggests that optimal reaction norm for developmental rates may be variable and hard to achieve in the heterogeneous pond environment. Mass at metamorphosis was not plastic across different pond durations but decreased at high larval density. Significant adaptive plasticity for growth rates appeared in environments that differed drastically in level of crowding conditions, both in the field and in the laboratory. The fact that survival of juveniles metamorphosed at high density ponds was a monotonic function of metamorphic size, implies that response to selection may occur in this population of natterjacks and that genetic variability in plasticity may be a reliable mechanism maintaining adaptive genetic variation in growth rates in the highly variable pond environment.Peer Reviewe
Sapillo moteado ibérico – Pelodytes ibericus Sánchez-Herráiz, Barbadillo, Machordom y Sanchíz, 2000
Anfibios - Orden Anura - Familia Pelodytidae en
la Enciclopedia Virtual de Vertebrados Españoles,
http://www.vertebradosibericos.org/. Versiones anteriores: 12-01-2005; 1-06-2009A comprehensive review of the natural history
of the Iberian parsley frog Pelodytes ibericus in Spain.Peer reviewe
Tritón pigmeo – Triturus pygmaeus Wolterstorff, 1905
Anfibios - Orden Caudata - Familia Salamandridae en la Enciclopedia Virtual de Vertebrados Españoles,
http://www.vertebradosibericos.org/. Versiones anteriores: 17-04-2007; 8-12-2007; 25-03-2008; 31-03-2009; 24-07-2014; 17-10-2014A comprehensive review of the natural history
of the Pygmy newt Triturus pygmaeus in Spain.Peer reviewe
Actual and osteochronological estimated age of natterjack toads (Bufo clalamita)FO CALAMITA)
Peer reviewe