246 research outputs found

    Effects of simulated daily precipitation patterns on annual plant populations depend on life stage and climatic region

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    <p>Abstract</p> <p>Background</p> <p>To improve the understanding of consequences of climate change for annual plant communities, I used a detailed, grid-based model that simulates the effect of daily rainfall variability on individual plants in five climatic regions on a gradient from 100 to 800 mm mean annual precipitation (MAP). The model explicitly considers moisture storage in the soil. I manipulated daily rainfall variability by changing the daily mean rain (DMR, rain volume on rainy days averaged across years for each day of the year) by ± 20%. At the same time I adjusted intervals appropriately between rainy days for keeping the mean annual volume constant. In factorial combination with changing DMR I also changed MAP by ± 20%.</p> <p>Results</p> <p>Increasing MAP generally increased water availability, establishment, and peak shoot biomass. Increasing DMR increased the time that water was continuously available to plants in the upper 15 to 30 cm of the soil (longest wet period, <it>LWP</it>). The effect of DMR diminished with increasing humidity of the climate. An interaction between water availability and density-dependent germination increased the establishment of seedlings in the arid region, but in the more humid regions the establishment of seedlings decreased with increasing DMR. As plants matured, competition among individuals and their productivity increased, but the size of these effects decreased with the humidity of the regions. Therefore, peak shoot biomass generally increased with increasing DMR but the effect size diminished from the semiarid to the mesic Mediterranean region. Increasing DMR reduced via <it>LWP </it>the annual variability of biomass in the semiarid and dry Mediterranean regions.</p> <p>Conclusion</p> <p>More rainstorms (greater DMR) increased the recharge of soil water reservoirs in more arid sites with consequences for germination, establishment, productivity, and population persistence. The order of magnitudes of DMR and MAP overlapped partially so that their combined effect is important for projections of climate change effects on annual vegetation.</p

    Global Soil Organic Carbon Estimates and the Harmonized World Soil Database

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    Global estimates of soil organic carbon stocks have been produced in the past to support the calculation of potential emissions of CO2 from the soil under scenarios of change land use/cover and climatic conditions (IPCC, 2006), but very few global estimates are presented as spatial data. For global spatial layers on soil parameters, the most recent and complete dataset is available as the Harmonized World Soil Database (HWSD) (Fisher et al., 2008).The HWSD represents a step forward towards a spatially more detailed and thematically more refined set of global soil data. During the evaluation of the data for generating estimates of global SOC stocks Version 1.1 of the HWSD revealed also some rough edges. Consequential are the values of bulk density attributed to soils high in organic carbon. In the evaluation the database was completed and suitable substitutions for bulk density for soil high in organic carbon were investigated. For the amended data the global SOC stock to 100cm soil depth is estimated at 1, 417 Pg C, although this estimate very much dependent on the ancillary data used. The amended HWSD was compared to data from 4 other global data sets on SOC stocks. The comparative evaluation has demonstrated that bulk density is the most important factor for estimating SOC stocks and mainly responsible for the differences between estimates. Moist affected from the variability in bulk density are SOC stocks in areas with soils which are high in organic carbon.JRC.H.5-Land Resources Managemen

    Philosophie der Tierforschung: Milieus und Akteure

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    Die Tierphilosophie ist eines der lebendigsten Felder der Gegenwartsphilosophie. Im Mittelpunkt stehen bislang die Frage nach dem Geist der Tiere, das Problem des Tier-Mensch-Unterschiedes und die Themenfelder der Tierethik. Die auf drei Bände angelegte »Philosophie der Tierforschung« wirft einen neuen Blick auf dieses Gebiet und ergänzt es durch eine stärkere Berücksichtigung des gesamten Kontextes der naturwissenschaftlichen Tierforschung, inklusive der philosophischen Hintergrundannahmen, der Forschungsverfahren und -orte, der Handlungslogiken, Denkstile und Sprachspiele der Forscherkollektive sowie der jeweils ausgewählten Modellorganismen. Stellten die ersten beiden, bereits erschienenen Bände der Reihe die Methoden und Programme sowie die Maximen und Konsequenzen der Tierforschung in den Mittelpunkt, widmet sich der dritte Band unter dem Leitgedanken der Forschungsumwelten den Milieus und Akteuren. Im Ausgang von der Tier-Mensch-Relationalität der Tierforschung werden dabei die verschiedenen Rollen der Forschenden und der erforschten Tiere mit dem Ziel einer Neukonfiguration des Untersuchungsfeldes herausgearbeitet

    Strategy for the dissemination of outputs at national, EU, and global levels

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    Dissemination of FACCE MACSUR will operate in a tiered manner to the scientific community, funding agencies, decision makers in policy and agri-food businesses, and the general public. Efforts by the MACSUR hub level are targeted at the supra-national level, while individual institutions target regional and national stakeholders.The dissemination approaches will include multiple and various methods of information distribution including• scientific papers and presentations,• conferences, congresses, workshops, and courses targeted to specific stakeholders,• a fully developed and interactive website,• regular newsletters,• flyers,• alignment of methodologies and protocols with other research networks or projects. Dissemination is both passive (web site, publications) and active (flyers, presentations, workshops held jointly with other projects or organizations, Twitter)

    FACCE MACSUR Joint Workshops 2015

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    FACCE MACSUR comprises many different groups whose work contribute to improving the European capacity of modelling agriculture with climate change and providing an assess­ment of these impacts for stakeholders. Some groups work on methodological issues in a single discipline, others work on cross-disciplinary concepts. The meeting provided an opportunity for the members of the groups to meet for intensive discussions and exchange of ideas, which is not as easily done in phone or video conferences. Various groups also met with each other to agree on work plans and common settings for research. Overall, 105 researchers attended the workshops. For coordinating work with the global program AgMIP, AgMIP's principle investigator John Antle attended the meeting and, meeting in a video call, coordination teams of MACSUR and AgMIP agreed to continue the successful collaboration in the future.Major overarching outcomes of the meetings were agreements on policy and climate scenarios recommended to be used within MACSUR, development of an approach to quantify effects of extreme climatic events on socio-economic indicators, and closer collaboration among several groups at the level of regional case studies

    Influence of Invading Aspen (Populus tremuloides) on the Nitrogen Cycle of North-American Prairie Ecosystems

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    In einem Grasland-Wald-Ökoton wurde untersucht, ob der gegenüber dem Graslandboden höhere Mineralstickstoffgehalt des Waldbodens mit dem Alter der Bäume, der Bodenfeuchte, der Lufttemperatur oder dem relativen Lichtgenuß im Wald zusammenhängt. Dazu wurden diese Faktoren in Espenhainen (Populus tremuloides) auf Radialtransekten, die in die angrenzende Prärie verlängert wurden, gemessen. Es zeigte sich, daß der Stickstoffgehalt mit abnehmender Bodenfeuchte ansteigt. Nur diese Korrelation war signifikant. Die Ergebnisse deuten an, daß der höhere Stickstoffgehalt in Hainböden auf eine geringere Stickstoffaufnahme der Hainarten bei Bodentrockenheit zurückzuführen ist. Als Alternative zu dieser Erklärung wurde die Annahme geprüft, daß die stickstoffärmere Streu in Wäldern wegen geringerer Evapotranspiration im Schatten schneller zersetzt wird als die stickstoffreichere Streu im benachbarten Grasland und dies zu einem höheren Mineralstickstoffgehalt im Waldboden führt. Dazu wurde der Einfluß der Streusorte (Grasgemisch oder Espe), des Biotoptyps (Grasland oder Espenhain) und der Beschattung (ohne oder mit künstlicher Beschattung) auf die Raten des Trockenmasseverlustes und der Stickstoffabgabe der Streu bestimmt. Je 2 g Ende April gesammelter Vorjahresstreu wurde in 1 dm2 großen Netzen Anfang Mai auf die Versuchsflächen ausgebracht. Zur Messung der Stickstoffauswaschung wurden unter die Streunetze Beutel mit Ionenaustauschern gelegt. Mit unbedeckten Austauscherbeuteln wurde die Stickstoffdeposition bestimmt. Je ein Viertel der Streunetze und Austauscherbeutel wurden nach 4, 9, 16 und 21 Wochen geerntet. Aus dem Masseverlust der Streu und der Stickstoffauswaschung wurden die Raten der Zersetzung, Stickstoffabgabe- und -anhäufung berechnet. Grasstreu wurde signifikant schneller (k= -1,36) als Espenstreu (k= -0,44) und beide Sorten jeweils in unbeschatteten Prärieteilflächen schneller als in anderen Teilflächen zersetzt. Die Grasstreu fing weniger Stickstoff aus der Deposition auf und ließ mehr davon durch als Espenstreu. Eine chemische Analyse der zersetzten Streu zeigte, daß bei Berücksichtigung der Deposition beide Sorten Stickstoff verloren hatten. Dieser Verlust war vermutlich durch Fragmentierung der Streu, jedoch nicht durch Mineralisation entstanden. Da entgegen der Annahme Espenstreu trotz Beschattung am langsamsten zersetzt wurde, wird Streuzersetzung als Erklärung des höheren Stickstoffgehaltes in Hainböden verworfen und stattdessen die Annahme beibehalten, daß Trockenheit die Stickstoffaufnahme im Hain begrenzt

    FACCE MACSUR Joint Workshops 2015

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    FACCE MACSUR comprises many different groups whose work contribute to improving the European capacity of modelling agriculture with climate change and providing an assess­ment of these impacts for stakeholders. Some groups work on methodological issues in a single discipline, others work on cross-disciplinary concepts. The meeting provided an opportunity for the members of the groups to meet for intensive discussions and exchange of ideas, which is not as easily done in phone or video conferences. Various groups also met with each other to agree on work plans and common settings for research. Overall, 105 researchers attended the workshops. For coordinating work with the global program AgMIP, AgMIP's principle investigator John Antle attended the meeting and, meeting in a video call, coordination teams of MACSUR and AgMIP agreed to continue the successful collaboration in the future.Major overarching outcomes of the meetings were agreements on policy and climate scenarios recommended to be used within MACSUR, development of an approach to quantify effects of extreme climatic events on socio-economic indicators, and closer collaboration among several groups at the level of regional case studies

    Hub website and administrative tasks

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    The Hub management has set up and is administering an interactive web site, organized the kickoff-workshop, developed the consortium agreement with 70 partners, developed logos and templates for use by members, published four newsletters, organized seven Project Steering Committee meetings and interacted with the FACCE JPI secretariat

    The FACCE MACSUR Mid-Term Scientific Conference: ‘Achievements, Activities, Advancement’

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    The mid-term meeting was held in Sassari, Sardinia, 1-4 April 2014. The meeting was attended by 120 researchers and stakeholders from 16 countries (Fig. 1). After a day of looking back on the achievements during the first two years and presenting results to stakeholders, researchers focused on fine-tuning the planning of remaining work for the project till May 2015 and preparations for a follow-up project (MACSUR2) till May 2017. On an excursion, scientists and stakeholders visited farms in the Oristano region, one of the regional case studies of MACSUR. The meeting was a unique opportunity in this pan-European project for discussing in person common issues with and among stakeholders of different regions and how to approach the impact of climate change to producing food in Europe in a world with a growing population. A report in La Nueva Sardegna highlighted the conference.Excursion: dairy sheep farm "Su Pranu"(Siamanna), dairy cattle farm "Sardo Farm" (Arborea), Arborea CooperativeRecordings of the presentations are available on YouTube: https://www.youtube.com/channel/UCr_joXlUIJ_NBW8cWOgh0_gThe presentations are available in the supplement to this issue. Short papers derived from the presentations are available on the conference website and in FACCE MACSUR Reports vol 3.The food consumed during lunches at the conference originated mostly from the Oristano region. Remaining food in good condition was donated to a charity organisation for needy people.Fig. 1. Number of participants per country

    Maps of grasslands in Europe

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    Modelling of climate effects on agriculture and food security at the European scale requires a harmonized spatially, explicit database of European land use. It can be used for scaling results of point models to an area. A recent review of land cover maps focused on the global scale (Köchy, 2010). European land use as a subset of global land use is contained in the product GlobCover representing the year 2009 with a resolution of 0.3 km. A European product is the CORINE data set with a resolution of 100 m and a minimum mapping unit of 25 ha representing the year 2006 (version 16, European Environmental Agency, 2012). For scaling the results obtained for individual points to larger regions one needs fine-grained maps using the same categories as represented by the sample points. The CORINE map of pasture cover (Fig. 1) has the advantage of being very fine-grained and the classification being supervised. The visual differences to coarser maps of cover matched to census (Fig. 4), however, indicate, that none of the existing maps is reflecting reality perfectly. Since MACSUR will likely work with official national statistics it may be preferable to use one of the census-calibrated maps. For a better match, official EU spatial reporting schemes may be used at a grain that ensures data privacy of the land owners
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