Lambdon PW, Pyšek P, Basnou C, Arianoutsou M, Essl F, Hejda M, Jarošík V, Pergl J, Winter M, Anastasiu P, Andriopoulos P, Bazos I, Brundu G, Celesti-Grapow L, Chassot P, Delipetrou P, Jogan N, Josefsson M, Kark S, Klotz S, Kokkoris Y, Kühn I (eds) (2008) Alien flora of Europe: species diversity, temporal trends, geographical patterns and research needs. Preslia 80: 101-149
Anastasiu P, Negrean G, Basnou C, Sirbu C, Oprea A (2008) A preliminary study of the neophytes of wetlands in Romania. In: Rabitsch W., Essl F.& Klingenstein F. (Eds.): Biological Invasions. Ecology to Conservation. NEOBIOTA 7: 180-190
Cristóbal J., Ninyerola M., Pons X. (2008) Modeling air temperature through a combination of remote sensing and GIS data. Journal of Geophysical Research Atmospheres. 113: 0-0.EnllaçDoi: 10.1029/2007JD009318
Air temperature is involved in many environmental processes such as actual and potential evapotranspiration, net radiation and species distribution. Ground meteorological stations provide important local data of air temperature, but a continuous surface for large and heterogeneous areas is also needed. In this paper we present a hybrid methodology between Remote Sensing and Geographical Information Systems to retrieve daily instantaneous, mean, maximum and minimum air temperatures (2002-2004) as well as monthly and annual mean, maximum and minimum air temperatures (2000-2005) on a regional scale (Catalonia, northeast of the Iberian Peninsula) by means of multiple regression analysis and spatial interpolation techniques. To perform multiple regression analysis we have used geographical and multiresolution remotely sensed variables as predictors. The geographical variables we have included are altitude, latitude, continentality and solar radiation. As remote sensing predictors, we have selected those variables that are most closely related with air temperature such as albedo, land surface temperature (LST) and NDVI obtained from Landsat-5 (TM), Landsat-7 (ETM+), NOAA (AVHRR) and TERRA (MODIS) satellites. The best air temperature models are obtained when remote sensing variables are combined with geographical variables: averaged R2 = 0.60 and averaged root mean square error (RMSE) = 1.75°C for daily temperatures, and averaged R2 = 0.86 and averaged RMSE = 1.00°C for monthly and annual temperatures. The results also show that combined models appear in a higher frequency than only geographical or only remote sensing models (87%, 11 % and 2% respectively) and that LST and NDVI are the most powerful remote sensing predictors in air temperature modeling. Copyright 2008 by The American Geophysical Union.
Dahbi A., Retana J., Lenoir A., Cerdá X. (2008) Nest-moving by the polydomous ant Cataglyphis iberica. Journal of Ethology. 26: 119-126.EnllaçDoi: 10.1007/s10164-007-0041-4
In this paper we analyze emigration from nests by the polydomous ant Cataglyphis iberica. Social carrying of workers of this species between different nests of the colony is frequent. In Bellaterra (Barcelona, NE Spain), we monitored field emigration of C. iberica by noting for each nest the migratory behavior of C. iberica workers and, when the nests were attacked by another ant species, Camponotus foreli, we noted the number of C. foreli workers involved in the attacks. Emigration of C. iberica from nests was highly variable. We suggest the main factor determining emigration by this species was attack by workers of C. foreli, so emigration from C. iberica nests was much faster when harassment by C. foreli increased. The system of multiple nests of C. iberica enables this species to abandon attacked nests and to reinstall their population in other nests of the same colony. This reduces risk to the colonies because the route between the different nests is well known by transporter workers. © 2007 Japan Ethological Society and Springer.
Dalsgaard B., Martín González A.M., Olesen J.M., Timmermann A., Andersen L.H., Ollerton J. (2008) Pollination networks and functional specialization: A test using Lesser Antillean plant-hummingbird assemblages. Oikos. 117: 789-793.EnllaçDoi: 10.1111/j.0030-1299.2008.16537.x
Network analysis has in recent years improved our understanding of pollination systems. However, there is very little information about how functionally specialized plants and pollinators interact directly and indirectly in pollination networks. We have developed a parameter, Functional specialization index, to quantify functional specialization in pollination networks. Using this parameter, we examined whether different sized hummingbirds visit a distinct set of flowers in five hummingbird-pollinated plant assemblages from the Lesser Antilles, obtaining a simple relationship between hummingbird body size, network parameter and ecological function. In the Lesser Antilles, functionally specialized hummingbird pollination is distinct for plant species pollinated by the largest hummingbird species, whereas the pollination niche gradually integrates with the insect pollinator community as hummingbird body size decreases. The network approach applied in this study can be used to validate functional specialization and community-level interdependence between plants and pollinators, and it is therefore useful for evaluating and predicting plant resilience to pollinator loss, presently a global concern. © 2008 The Authors.
Sol D (2008) Revisiting the cognitive buffer hypothesis for the evolution of large brains. Biology Letters doi:10.1098/rsbl.2008.0621.
Sol D, Price TD (2008) Brain size and body size diversification in birds. American Naturalist 172: 170-177.
Price T, Sol D (2008) Genetics of Colonizing Species. American Naturalist 172: S1-S3.
Sol D (2008) ¿Existen los buenos invasores? El problema de los animales para sobrevivir en nuevos ambientes. En: M. Vilà et al. (eds.), Invasiones biológicas.CSIC, Madrid pp. 65-76.
De Las Heras J., Moya D., López-Serrano F.R., Eugenio M., Espelta J.M. (2008) Aleppo pine regeneration after fire along an aridity gradient. WIT Transactions on Ecology and the Environment. 119: 289-295.EnllaçDoi: 10.2495/FIVA080291
In the Mediterranean Basin, the number of large-scale fires and, consequently, the area of regenerated forests after a fire have been increasing over the last few decades. Mediterranean pine tree stand regeneration shows differences in growth and reproductive characteristics depending on site quality. Aleppo pine (Pinus halepensis Mill.) is an important obligate seeder species occupying a large surface in this area. In order to study growth and reproductive characteristics depending on different climatic conditions, six sites with similar characteristics (edaphic, exposure, slope) burned in the summer of 1994 were selected along a climate gradient. Different precipitation values determined three different ombroclimates: dry-subhumid, dry and semi-arid. Ten years after the fires, data on growth and cone production were collected from these areas in order to study the pattern of growth and reproduction and the influence of site quality (climate) on them. Results showed significantly higher values for growth and several cone characteristics; furthermore, they were positively related to site quality. Viability and seed germination percentages were higher in sites located in dry-subhumid areas. Serotiny was highest in dry locations (southern sites), and lower percentages were found in low tree density sites. The number of reproductive trees was higher northwards and the reproductive phase was reached in younger stands with lower tree density. In conclusion, results showed a geographical gradient based upon growth and reproductive characteristics, decreasing southwards in contrast to serotiny, which increases in southern sites. Density was found to be a significant factor influencing overall pine stand development.
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