. The impact of pre-dispersal seed predators on the reproductive output of two Euphorbia.

Boieiro M, Rego C, Serrano A, Espadaler X (2010) . The impact of pre-dispersal seed predators on the reproductive output of two Euphorbia. Acta Oecologica 36: 227-233.

First record of Lasius paralienus Seifert, 1992 (Hymenoptera : Formicidae) from France and Andorra.

Bernadou A, Galkowski C, Le Goff A, Fourcassié V, Espadaler X (2010) First record of Lasius paralienus Seifert, 1992 (Hymenoptera : Formicidae) from France and Andorra. Myrmecological News 13: 111-113.

Hormigas (Hymenoptera, Formicidae) de los acantilados de l'Avenc de Tavertet (Osona).

García F, Espadaler X, Echave P, Vila R (2010) Hormigas (Hymenoptera, Formicidae) de los acantilados de l'Avenc de Tavertet (Osona). Boletín de la Sociedad entomológica Aragonesa 47: 33-37.

Nuevos casos y hospedadores de Myrmicinosporidium durum Hölldobler, 1933 (Fungi).

García F, Espadaler X (2010) Nuevos casos y hospedadores de Myrmicinosporidium durum Hölldobler, 1933 (Fungi). Iberomyrmex 2: 5-11.

Formigues de les Planes de Son i mata de València.

Espadaler X, Roig X, Gómez K, García F (2010) Formigues de les Planes de Son i mata de València. Treballs de la Institució Catalana d'Història Natural 16: 609-627.

A simple method to differentially exclude ants from tree canopies based on ant body size.

Romeu-Dalmau C, Espadaler X, Piñol J (2010) A simple method to differentially exclude ants from tree canopies based on ant body size. Methods in Ecology and Evolution 1: 188-191.

Plant-soil interactions and acclimation to temperature of microbial-mediated soil respiration may affect predictions of soil CO2 efflux

Yuste J.C., Ma S., Baldocchi D.D. (2010) Plant-soil interactions and acclimation to temperature of microbial-mediated soil respiration may affect predictions of soil CO2 efflux. Biogeochemistry. 98: 127-138.
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Doi: 10.1007/s10533-009-9381-1

Resum:

It is well known that microbial-mediated soil respiration, the major source of CO2 from terrestrial ecosystems, is sensitive to temperature. Here, we hypothesize that some mechanisms, such as acclimation of microbial respiration to temperature and/or regulation by plant fresh C inputs of the temperature sensitivity of decomposition of soil organic matter (SOM), should be taken into account to predict soil respiration correctly. Specifically, two hypotheses were tested: (1) under warm conditions, temperature sensitivity (Q10) and basal rates of microbial-mediated soil respiration (Bs20, respiration at a given temperature) would be primarily subjected to presence/absence of plant fresh C inputs; and (2) under cold conditions, where labile C depletion occurred more slowly, microbial-mediated soil respiration could adjust its optimal temperatures to colder temperatures (acclimation), resulting in a net increase of respiration rates for a given temperature (Bs20). For this purpose, intact soil cores from an oak savanna ecosystem were incubated with sufficient water supply at two contrasting temperatures (10 and 30°C) during 140 days. To study temperature sensitivity of soil respiration, short-term temperature cycles (from 5 to 40°C at 8 h steps) were applied periodically to the soils. Our results confirmed both hypotheses. Under warm conditions ANCOVA and likelihood ratio tests confirmed that both Q10 and Bs20 decreased significantly during the incubation. Further addition of glucose at the end of the incubation period increased Bs20 and Q10 to initial values. The observed decrease in temperature sensitivity (Q10) in absence of labile C disagrees with the broadly accepted fact that temperature sensitivity of the process increases as quality of the substrate decreases. Our experiment also shows that after 2 months of incubation cold-incubated soils doubled the rates of respiration at cold temperatures causing a strong increase in basal respiration rates (Bs20). This suggest that microbial community may have up-regulated their metabolism at cold conditions (cold-acclimation), which also disagrees with most observations to date. The manuscript discusses those two apparent contradictions: the decrease in temperature sensitivity in absence of labile C and the increase in microbial-mediated soil respiration rates at cold temperatures. While this is only a case study, the trends observed could open the controversy over the validity of current soil respiration models. © 2009 The Author(s).

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JPEG2000 encoding of images with NODATA regions for remote sensing applications

Zabala A., Gonzalez-Conejero J., Serra-Sagrista J., Pons X. (2010) JPEG2000 encoding of images with NODATA regions for remote sensing applications. Journal of Applied Remote Sensing. 4: 0-0.
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Doi: 10.1117/1.3474978

Resum:

The aim of this work is to, within the JPEG2000 framework, enhance the coding performance obtained for images that contain regions without useful information, or without information at all, here named as NODATA regions. In Geographic Information Systems (GIS) and in Remote Sensing (RS), NODATA regions arise due to several factors, such as geometric and radiometric corrections, atmospheric events, the overlapping of successive layers of information, etc. Most coding systems are not devised to consider these regions separately from the rest of the image, sometimes causing a loss in the coding efficiency and in the post-processing applications. We propose two approaches that address this issue; the first technique (Average Data Region, ADR) is carried out as simple pre-processing and the second technique (Shape-Adaptive JPEG2000, SA-JPEG2000) modifies the coding system to avoid the regions without information. Experimental results, performed on data from real applications and different scenarios, suggest that the proposed approaches can achieve, e.g., for SA-JPEG2000, a Signal-to-Noise Ratio improvement of about 8 dB. Moreover, in a post-processing application such as a digital classification, the best classification results are obtained when the proposed approaches SA-JPEG2000 and ADR are applied. © 2010 Society of Photo-Optical Instrumentation Engineers.

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