Modelling Grass Productivity in the Brazilian Amazon

The Amazon Basin covers an area of 7 million km2, and the central part is almost entirely located within Brazilian territory. This region has the highest rates of deforestation in the world, and the total area deforested now exceeds 600,000 km2. Cattle pasture represents the largest single use (about 70%) of this once-forested land in most of the Brazilian Basin, with an estimated area of 20 million hectares. Our main objective was to simulate grass productivity in different forest to pasture chronosequences within the Brazilian Amazon

A meta-analysis of gender differences in leadership effectiveness

Despite years of evidence showing that men are typically considered to be more appropriate and effective in leadership positions than women, a recent debate has emerged over the potential existence of a female leadership advantage in certain contexts (Eagly & Carli, 2003a; Vecchio, 2003; Eagly & Carli, 2003b). This meta-analysis aims to contribute to this debate in the literature by quantitatively summarizing gender differences in leadership effectiveness using 99 independent samples from 95 studies. Results show that when all leadership contexts are considered together there is a non- significant gender difference in leadership effectiveness. Additionally, this study examines the influence of contextual moderators developed from role congruity theory (Eagly & Karau, 2002) and some competing theoretical frameworks. Overall, the findings support the core tenets of role congruity theory—that prejudice against female leaders can vary depending on a variety of features of the leadership context and characteristics of the perceivers of the leader’s effectiveness. However, some of the hypotheses proposed by role congruity theory were only partially supported. The results of this meta- analysis point to ways in which the theory can be updated and expanded by taking into account findings supported by other theories presented in the literature on gender and leadership. Finally, this meta-analysis provides important practical implications for reducing the barriers women may face throughout the leadership labyrinth as they pursue the most elite leadership positions

Soil Aggregation and Soil Organic Carbon Stabilization: Effects of Management in Semiarid Mediterranean Agroecosystems

In semiarid agroecosystems of the Ebro valley (NE Spain) soils are characterized by low soil organic matter (SOM) and a weak structure. In this study we investigated the individual and combined effect of tillage system (no-tillage, NT; reduced tillage, RT; conventional tillage, CT) and cropping system (barley–fallow rotation at the Peñaflor site, PN-BF and continuous barley at the Peñaflor site, PN-BB) on soil organic carbon (SOC) storage as well as the physical protection of SOM fractions by soil aggregates in three long-term experimental sites. In both cropping systems, total SOC content was more than 30% higher in NT compared with CT in the 0- to 5-cm depth. The suppression of fallowing in the PN-BB cropping system led to a greater SOC stabilization only in NT. In all the three sites, greater proportion of water-stable macroaggregates (>250 µm) was found under NT than under CT in the 0- to 5-cm depth. Macroaggregate organic C concentration (250–2000 µm) was greater in NT compared with CT in the BB cropping system, but did not differ with tillage treatment in the PN-BF rotation. Greater proportion of microaggregates within macroaggregates in NT compared with CT was only found in the Agramunt site (AG). However, greater C stabilized inside these microaggregates was observed in AG, Selvanera site (SV), and PN-BB in the 0- to 5-cm depth. The results of this study demonstrate that in the semiarid Mediterranean agroecosystems of the Ebro valley, the adoption of NT together with the suppression of long-fallowing period can significantly increase the amount of SOC stabilized in the soil surface and improve soil structure and aggregation.This research was supported by the Comisión Interministerial de Ciencia y Tecnología of Spain (Grants AGL2001-2238-CO2-01, AGL 2004-07763-C02-02 and AGL2007-66320-CO2-02/AGR) and the European Union (FEDER funds).Peer reviewe

Incorporation of crop phenology in Simple Biosphere Model (SiBcrop) to improve land-atmosphere carbon exchanges from croplands

Croplands are man-made ecosystems that have high net primary productivity during the growing season of crops, thus impacting carbon and other exchanges with the atmosphere. These exchanges play a major role in nutrient cycling and climate change related issues. An accurate representation of crop phenology and physiology is important in land-atmosphere carbon models being used to predict these exchanges. To better estimate time-varying exchanges of carbon, water, and energy of croplands using the Simple Biosphere (SiB) model, we developed crop-specific phenology models and coupled them to SiB. The coupled SiB-phenology model (SiBcrop) replaces remotely-sensed NDVI information, on which SiB originally relied for deriving Leaf Area Index (LAI) and the fraction of Photosynthetically Active Radiation (fPAR) for estimating carbon dynamics. The use of the new phenology scheme within SiB substantially improved the prediction of LAI and carbon fluxes for maize, soybean, and wheat crops, as compared with the observed data at several AmeriFlux eddy covariance flux tower sites in the US mid continent region. SiBcrop better predicted the onset and end of the growing season, harvest, interannual variability associated with crop rotation, day time carbon uptake (especially for maize) and day to day variability in carbon exchange. Biomass predicted by SiBcrop had good agreement with the observed biomass at field sites. In the future, we will predict fine resolution regional scale carbon and other exchanges by coupling SiBcrop with RAMS (the Regional Atmospheric Modeling System)

\u3ci\u3eCorrigendum to\u3c/i\u3e “Incorporation of crop phenology in Simple Biosphere Model (SiBcrop) to improve land-atmosphere carbon exchanges from croplands” published in Biogeosciences, 6, 969–986, 2009

In the above mentioned manuscript a mistake in Fig. 11 occured. The corrected version of the figure is as follows

Agricultural climate change mitigation : Carbon calculators as a guide for decision making

This is an Accepted Manuscript of an article published by Taylor & Francis Group in International Journal of Agricultural Sustainability on 9 November 2017, available online: https://doi.org/10.1080/14735903.2017.1398628. Under embargo. Embargo end date: 9 November 2018.The dairy industry is receiving considerable attention in relation to both its significant greenhouse gas (GHG) emissions, and it’s potential for reducing those emissions, contributing towards meeting national targets and driving the industry towards sustainable intensification. However, the extent to which improvements can be made is dependent on the decision making processes of individual producers, so there has been a proliferation of carbon accounting tools seeking to influence those processes. This paper evaluates the suitability of such tools for driving environmental change by influencing on-farm management decisions. Seven tools suitable for the European dairy industry were identified, their characteristics evaluated, and used to process data relating to six scenario farms, emulating process undertaken in real farm management situations. As a result of the range of approaches taken by the tools, there was limited agreement between them as to GHG emissions magnitude, and no consistent pattern as to which tools resulted in the highest/lowest results. Despite this it is argued, that as there was agreement as to the farm activities responsible for the greatest emissions, the more complex tools were still capable of performing a ‘decision support’ role, and guiding management decisions, whilst others could merely focus attention on key issues.Peer reviewe

Genome sequencing of ovine isolates of Mycobacterium avium subspecies paratuberculosis offers insights into host association

<p>Abstract</p> <p>Background</p> <p>The genome of <it>Mycobacterium avium </it>subspecies <it>paratuberculosis </it>(<it>MAP</it>) is remarkably homogeneous among the genomes of bovine, human and wildlife isolates. However, previous work in our laboratories with the bovine K-10 strain has revealed substantial differences compared to sheep isolates. To systematically characterize all genomic differences that may be associated with the specific hosts, we sequenced the genomes of three U.S. sheep isolates and also obtained an optical map.</p> <p>Results</p> <p>Our analysis of one of the isolates, <it>MAP </it>S397, revealed a genome 4.8 Mb in size with 4,700 open reading frames (ORFs). Comparative analysis of the <it>MAP </it>S397 isolate showed it acquired approximately 10 large sequence regions that are shared with the human <it>M. avium </it>subsp. <it>hominissuis </it>strain 104 and lost 2 large regions that are present in the bovine strain. In addition, optical mapping defined the presence of 7 large inversions between the bovine and ovine genomes (~ 2.36 Mb). Whole-genome sequencing of 2 additional sheep strains of <it>MAP </it>(JTC1074 and JTC7565) further confirmed genomic homogeneity of the sheep isolates despite the presence of polymorphisms on the nucleotide level.</p> <p>Conclusions</p> <p>Comparative sequence analysis employed here provided a better understanding of the host association, evolution of members of the <it>M. avium </it>complex and could help in deciphering the phenotypic differences observed among sheep and cattle strains of <it>MAP</it>. A similar approach based on whole-genome sequencing combined with optical mapping could be employed to examine closely related pathogens. We propose an evolutionary scenario for <it>M. avium </it>complex strains based on these genome sequences.</p