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A roadmap for Antarctic and Southern Ocean science for the next two decades and beyond
- M.C. Kennicutt II, S.L. Chown, J.J. Cassano, D. Liggett, L.S. Peck, R. Massom, S.R. Rintoul, J. Storey, D.G. Vaughan, T.J. Wilson, I. Allison, J. Ayton, R. Badhe, J. Baeseman, P.J. Barrett, R.E. Bell, N. Bertler, S. Bo, A. Brandt, D. Bromwich, S.C. Cary, M.S. Clark, P. Convey, E.S. Costa, D. Cowan, R. Deconto, R. Dunbar, C. Elfring, C. Escutia, J. Francis, H.A. Fricker, M. Fukuchi, N. Gilbert, J. Gutt, C. Havermans, D. Hik, G. Hosie, C. Jones, Y.D. Kim, Y. Le Maho, S.H. Lee, M. Leppe, G. Leitchenkov, X. Li, V. Lipenkov, K. Lochte, J. López-Martínez, C. Lüdecke, W. Lyons, S. Marenssi, H. Miller, P. Morozova, T. Naish, S. Nayak, R. Ravindra, J. Retamales, C.A. Ricci, M. Rogan-Finnemore, Y. Ropert-Coudert, A.A. Samah, L. Sanson, T. Scambos, I.R. Schloss, K. Shiraishi, M.J. Siegert, J.C. Simões, B. Storey, M.D. Sparrow, D.H. Wall, J.C. Walsh, G. Wilson, J.G. Winther, J.C. Xavier, H. Yang, W.J. Sutherland
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- Journal:
- Antarctic Science / Volume 27 / Issue 1 / February 2015
- Published online by Cambridge University Press:
- 18 September 2014, pp. 3-18
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Antarctic and Southern Ocean science is vital to understanding natural variability, the processes that govern global change and the role of humans in the Earth and climate system. The potential for new knowledge to be gained from future Antarctic science is substantial. Therefore, the international Antarctic community came together to ‘scan the horizon’ to identify the highest priority scientific questions that researchers should aspire to answer in the next two decades and beyond. Wide consultation was a fundamental principle for the development of a collective, international view of the most important future directions in Antarctic science. From the many possibilities, the horizon scan identified 80 key scientific questions through structured debate, discussion, revision and voting. Questions were clustered into seven topics: i) Antarctic atmosphere and global connections, ii) Southern Ocean and sea ice in a warming world, iii) ice sheet and sea level, iv) the dynamic Earth, v) life on the precipice, vi) near-Earth space and beyond, and vii) human presence in Antarctica. Answering the questions identified by the horizon scan will require innovative experimental designs, novel applications of technology, invention of next-generation field and laboratory approaches, and expanded observing systems and networks. Unbiased, non-contaminating procedures will be required to retrieve the requisite air, biota, sediment, rock, ice and water samples. Sustained year-round access to Antarctica and the Southern Ocean will be essential to increase winter-time measurements. Improved models are needed that represent Antarctica and the Southern Ocean in the Earth System, and provide predictions at spatial and temporal resolutions useful for decision making. A co-ordinated portfolio of cross-disciplinary science, based on new models of international collaboration, will be essential as no scientist, programme or nation can realize these aspirations alone.
Screening of plants from diversified natural grasslands for their potential to combine high digestibility, and low methane and ammonia production
- D. Macheboeuf, L. Coudert, R. Bergeault, G. Lalière, V. Niderkorn
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A total of 156 plant species from 35 botanical families collected from diversified grasslands in the French Massif Central were screened in vitro for their potential to combine high nutritive value for ruminants and a reduced impact on the environment. The vegetative part of plants were analyzed for their chemical composition and incubated in a batch system containing buffered rumen fluid at 39°C for 24 h. The gas production and composition were recorded, and the fermentation end-product concentrations in the incubation medium and the in vitro true organic matter digestibility (IVTOMD) were determined. The results were expressed relative to perennial ryegrass (PRG) values used as a reference. We observed that no relationship between methane (CH4) and volatile fatty acids (VFA) was evidenced for 12 plants, the fermentation of these plants producing significantly less CH4 for a similar level of VFA production. In all, 13 plants showed 50% less CH4 production per unit of organic matter truly digested (OMTD) than PRG. Among these plants, two reduced CH4 by more than 80% and four species had an IVTOMD higher than 80%. The underlying modes of action seem to be different among plants: some result in an accumulation of H2 in the fermentation gas, but others do not. In terms of nitrogen (N) use efficiency, the fermentation of 37 plants halved the ratio between ammonia (N–NH3) and plant N content compared with PRG, of which six showed a complete absence of N–NH3 in the medium. Among these plants, four maintained the IVTDMO at values not significantly different from PRG (P>0.05). Considering the multi-criteria selection, 16 plants showed simultaneously a reduction of more than 80% in N–NH3 production and 30% in CH4 emission per unit of OMTD compared with PRG, including three with an IVTOMD higher than 80%. Overall, the botanical families that reduced simultaneously CH4 and N–NH3 most efficiently were the Rosaceae, Onagraceae, Polygonaceae and Dipsacaceae. The Onagraceae also gave high values for IVTOMD.