Eugenio Rico

LA FAMILIA ELMIDAE ESTA CONSTITUIDA, EN LA PENINSULA IBERICA E ISLAS BALEARES, POR 32 ESPECIES Y SUBESPECIES, SIENDO ESTA ZONA LA DE MAYOR DIVERSIFICACION DE LA REGION PALEARTICA OCCIDENTAL, Y CON UN GRAN COMPONENTE DE ELEMENTOS ENDEMICOS. EL ANALISIS DE LA DISTRIBUCION DE LA FAMILIA A DISTINTOS NIVELES DE PERCEPCION INDICA QUE LOS FACTORES HISTORICOS, ESPECIALMENTE LAS GLACIACIONES ACAECIDAS DURANTE EL CUATERNARIO, NO SON FUNDAMENTALES A LA HORA DE EXPLICAR ESTA, SIENDO LOS FACTORES ECOLOGICOS LOS QUE ADQUIEREN UNA IMPORTANCIA BASICA, DE ESTE MODO, LA MAYOR DIVERSIFICACION EXISTENTE EN LA PENINSULA SERIA UN REFLEJO DE PROCESOS DE MADURACION DE LOS ECOSISTEMAS QUE CONLLEVARIAN PROCESOS DE ESPECIACION, Y NO UN RESULTADO DE PROCESOS DE ACUMULACION DE ESPECIES EN BUSCA DE REFUGIO EN EPOCAS DE GLACIACION.

The Arctic soil communities play a vital role in stabilizing and decomposing soil carbon, which affects the global carbon cycling. Studying the food web structure is critical for understanding biotic interactions and the functioning of these ecosystems. Here, we studied the trophic relationships of (microscopic) soil biota of two different Arctic spots in Ny-Ålesund, Svalbard, within a natural soil moisture gradient by combining DNA analysis with stable isotopes as trophic tracers. The results of our study suggested that the soil moisture strongly influenced the diversity of soil biota, with the wetter soil, having a higher organic matter content, hosting a more diverse community. Based on a Bayesian mixing model, the community of wet soil formed a more complex food web, in which bacterivorous and detritivorous pathways were important in supplying carbon and energy to the upper trophic levels. In contrast, the drier soil showed a less diverse community, lower trophic complexity, with the green food web (via unicellular green algae and gatherer organisms) playing a more important role in channelling energy to higher trophic levels. These findings are important to better understand the soil communities inhabiting the Arctic, and for predicting how the ecosystem will respond to the forthcoming changes in precipitation regimes.

espanolEl CEDEX ha participado desde 2001 en diferentes proyectos antarticos junto con numerosas instituciones espanolas y de otros paises, desarrollando su actividad cientifica en el Campamento internacional de la Peninsula Byers (Isla Livingston, islas Shetland del Sur, Antartida), lugar catalogado como Area Antartica de Especial Proteccion (Antarctic Specially Protected Arca No. 126) por la importancia y valor de sus ecosistemas terrestres y acuaticos. Es una de las mayores areas libres de hielo de la Antartida maritima, en la que se localiza la mayor variedad de ambientes y procesos geologicos, hidrologicos o biologicos de toda la region, con un estado de conservacion pristino. La Peninsula Byers esta considerada la zona limnologica mas significativa de toda la region de la Peninsula Antartica por albergar un gran numero de lagos, arroyos y charcas, con una excepcional biodiversidad de fauna y flora, contando con la presencia simultanea de gran parte de las especies mas singulares, endemicas o representativas de la Antartida. Ademas, el registro sedimentario de los lagos de este enclave constituye uno de los archivos mas completo y extenso de la region de la Peninsula Antartica para el estudio paleoecologico y climatico de la historia del Holoceno. Considerada un "hotspot" antartico en terminos de biodiversidad, y localizada en una de las zonas del planeta donde se esta detectando mas significativamente el calentamiento global, la Peninsula Byers reune todas las caracteristicas necesarias para ser considerada un lugar idoneo de referencia internacional para estudios y programas de seguimiento ambiental a largo plazo no solo limnologicos, sino tambien terrestres o costeros. EnglishSince 2001 CEDEX has taken part in many Antarctic joint research projects with different' institutions from Spain and other countries, developing scientific activities in the International Camp Byers Peninsula (Livingston Island, South Shetland Islands, Antarctica). This place was designed as an Antarctic Specially Protected Area (No. 126) because the importance and value of its terrestrial and aquatic habitats. It is one of the largest ice free areas of maritime Antarctica, with the highest diversity of environments and geological, hydrological and biological processes in the whole region, all of them in a pristine state. Byers Peninsula is considered the most significant limnological area in the .Antarctic Peninsula region because it hosts a high number of lakes, ponds and streams, with an exceptional fauna and flora diversity ,including the most singular, representative or endemic Antarctic species. Furthermore, the lakes sedimentary record is one the widest and complete archives in Antarctic Peninsula region for the palaeoecological and climatic study of the Holocene. Because Byers Peninsula is an Antartic biodiversity "hotspot", and it is located in one of the areas in the Earth where global warming is being more significant, it must be considered as a suitable international al reference site for limnetic, terrestrial and coastal studies, and long term monitoring programmes.

... EUGENIO RICO 136 ... Asturias: Villampero (Salas), Nonoya River, 100 m, 29TQJ21, G. González leg., 15-06-82: 1. Cáceres: Tornavacas, Jerte River, 30TTK7260, García de Jalón leg., 08-06-86: 1. León: Cerulleda, 1305 m, 30TUN0265, Valladares leg., 21-08-83: 3; Cofiñal ...

... Among these species, some have incomplete descriptions and types are missing, for example L. maritimus and L. pygmaeus (KA Coates, personal com-munication). ... Tetraploids and pentaploids have sperm funnels reduced and with conical shape (see Fig. 1b in Coates 1995). ...

espanolEl CEDEX ha participado desde 2001 en diferentes proyectos antarticos junto con numerosas instituciones espanolas y de otros paises, desarrollando su actividad cientifica en el Campamento internacional de la Peninsula Byers (Isla Livingston, islas Shetland del Sur, Antartida), lugar catalogado como Area Antartica de Especial Proteccion (Antarctic Specially Protected Arca No. 126) por la importancia y valor de sus ecosistemas terrestres y acuaticos. Es una de las mayores areas libres de hielo de la Antartida maritima, en la que se localiza la mayor variedad de ambientes y procesos geologicos, hidrologicos o biologicos de toda la region, con un estado de conservacion pristino. La Peninsula Byers esta considerada la zona limnologica mas significativa de toda la region de la Peninsula Antartica por albergar un gran numero de lagos, arroyos y charcas, con una excepcional biodiversidad de fauna y flora, contando con la presencia simultanea de gran parte de las especies mas singular...

La estructura trófica de las comunidades planctónicas de los lagos antárticos se caracteriza por su sencillez, estando funcionalmente dominada por microorganismos. En estas cadenas tróficas el zooplancton, cuando está presente, ocupa generalmente la posición de consumidores superiores. Estos sistemas constituyen un marco muy adecuado en el que evaluar ciertos aspectos de la ecología trófica y funcional. Nuestro propósito ha sido valorar la aplicabilidad de una serie de teorías ecológicas, relativas a las relaciones tróficas, al flujo de energía y a la relativa importancia de los factores tanto abióticos como bióticos como elementos que expliquen el funcionamiento de estos ecosistemas en zonas polares sometidas a un fuerte control físico. Estudios experimentales llevados a cabo en lagos de la Península Byers (Isla Livingston) por nuestro grupo de investigación han puesto de manifiesto como determinadas interacciones bióticas, como la depredación, podrían ejercer este efecto estructur...

Bacterioplankton summer dynamics in a maritime Antarctic lake Maritime Antarctica shows less severe weather conditions than continental Antarctica, thereby allowing an important thaw process during the austral summer that increases both light availability for primary production and the inputs of nutrients and organic matter through run-off. Thus, a rapid development of certain phytoplankton groups is favoured at the beginning of the austral summer as a direct effect of the higher availability of light and nutrients after the ice thaw. Inputs of allochthonous organic matter from microbial mats and moss carpets distributed across the catchment also enhance the abundance of heterotrophic bacterioplankton. Indeed, the bacterioplankton abundance and the availability of organic matter are correlated for each studied depth, revealing a possible differential use of the organic matter. Additionally, the availability and dynamics of different types of dissolved organic matter (autochthonous a...

Crayfish are among the largest aquatic macroinvertebrates in rivers and streams. Their trophic ecology is important for the understanding of the functioning of benthic communities. This is relevant in key areas, such as headwaters, as they partly condition the processes occurring downstream. To shed light on the effects of native white-clawed crayfish,Austropotamobius pallipes, on local macroinvertebrate assemblages from running headwaters, a three-month mesocosm-based field study was designed. Collection and subsequent analysis of benthic samples under different crayfish density levels yielded a set of metrics indicative of short-term impacts at general and taxonomic scales. Neither significant positive nor negative effects on the community were evident in terms of richness, diversity, dominance and biomass. A combination of highly patched distributions of macroinvertebrates along with a weak impact of crayfish foraging activity is considered to explain this lack of effects. Only t...

The biological activity of marine vertebrates represents an input of nutrients for Antarctic terrestrial biota, with relevant consequences for the entire ecosystem. Even though microbial mats assemble most of the biological diversity of the non-marine Antarctica, the effects of the local macrofauna on these microecosystems remain understudied. Using 16S rRNA gene sequencing, 13C and 15N stable isotopes, and by characterizing the P and N-derived nutrient levels, we evaluated the effects of penguins and other marine vertebrates on four microbial mats located along the Antarctic Peninsula. Our results show that P concentrations, C/N and N/P ratios, and δ15N values of “penguin-impacted” microbial mats were significantly higher than values obtained for “macrofauna-free” sample. Nutrients derived from penguin colonies and other marine vertebrates altered the trophic interactions of communities within microbial mats, as well as the relative abundance and trophic position of meiofaunal grou...

ABSTRACTThe esterases and lipases from the α/β hydrolase superfamily exhibit an enormous sequence diversity, fold plasticity, and activities. Here, we present the comprehensive sequence and biochemical analyses of seven distinct esterases and lipases from the metagenome of Lake Arreo, an evaporite karstic lake in Spain (42°46′N, 2°59′W; altitude, 655 m). Together with oligonucleotide usage patterns and BLASTP analysis, our study of esterases/lipases mined from Lake Arreo suggests that its sediment contains moderately halophilic and cold-adapted proteobacteria containing DNA fragments of distantly related plasmids or chromosomal genomic islands of plasmid and phage origins. This metagenome encodes esterases/lipases with broad substrate profiles (tested over a set of 101 structurally diverse esters) and habitat-specific characteristics, as they exhibit maximal activity at alkaline pH (8.0 to 8.5) and temperature of 16 to 40°C, and they are stimulated (1.5 to 2.2 times) by chloride ion...

ABSTRACT Abstract Southern elephant seals (Mirounga leonina) are apex predators of marine Antarctic food webs, and variations in their populations have been linked to environmental changes. Consequently, measuring and reporting the status of elephant seal populations provide insights into the environmental status of Antarctica. Here, we present new information on the size of the elephant seal subpopulation on Byers Peninsula (Livingston Island, South Shetland Islands, maritime Antarctica). Based on a total count of 1,510 pups, we estimated a total subpopulation size of 5,530 individuals by using a conversion factor of 3.5. This represents an increase of 150 % since the subpopulation was first counted 30 years ago. Based on this finding, we hypothesize that the overall South Georgia stock, to which the subpopulation we estimated on Byers Peninsula belongs, could be increasing instead of remaining stable as previously thought.