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Cambridge, United Kingdom

Cutler N.A.,Scott Polar Research Institute | Chaput D.L.,Smithsonian Institution | van der Gast C.J.,UK Center for Ecology and Hydrology
Soil Biology and Biochemistry | Year: 2014

Soil microbial communities (SMCs) play a critical role in the cycling of carbon and nutrients in terrestrial ecosystems, as well as regulating plant productivity and diversity. However, very little is known about long-term (decades-centuries) structural changes in these communities. The development of aboveground-belowground linkages during century-scale succession is also poorly understood. Our study addressed this knowledge gap by investigating SMC and plant communities undergoing primary succession on an 850-year chronosequence of lava flows in Iceland. We hypothesised that communities of microfungi and bacteria would respond to progressive changes in vegetation and that SMC diversity would increase with terrain age. Soil samples were collected from three lava flows at different stages of primary succession (165, 621 and 852 years after lava flow emplacement). Plant community composition was surveyed as the samples were collected. The composition of the SMCs present in the soil was determined using amplicon pyrosequencing. The physical and chemical properties of the soil were also analysed. The results of the study indicated changes in plant and fungal communities with increasing terrain age. Distinct plant and fungal assemblages were identified on the three sites and both communities became richer and more diverse with increasing terrain age. There was also evidence to suggest the development of mycorrhizal associations on older sites. In contrast, the composition and structure of the bacterial communities did not change systematically with terrain age. Similarly, there were few changes in soil properties: SOM concentrations and pH, both of which have been demonstrated to be important to SMCs, were constant across the chronosequence. These results suggest that plant community composition is significant for fungal communities, but less relevant for bacterial communities. This finding has implications for studies of primary succession and the biogeochemical impact of vegetation change in high-latitude ecosystems. © 2013 Elsevier Ltd. Source

Gutt J.,Alfred Wegener Institute for Polar and Marine Research | Bertler N.,Victoria University of Wellington | Bracegirdle T.J.,Natural Environment Research Council | Buschmann A.,Alfred Wegener Institute for Polar and Marine Research | And 9 more authors.
Global Change Biology | Year: 2015

A quantitative assessment of observed and projected environmental changes in the Southern Ocean (SO) with a potential impact on the marine ecosystem shows: (i) large proportions of the SO are and will be affected by one or more climate change processes; areas projected to be affected in the future are larger than areas that are already under environmental stress, (ii) areas affected by changes in sea-ice in the past and likely in the future are much larger than areas affected by ocean warming. The smallest areas (<1% area of the SO) are affected by glacier retreat and warming in the deeper euphotic layer. In the future, decrease in the sea-ice is expected to be widespread. Changes in iceberg impact resulting from further collapse of ice-shelves can potentially affect large parts of shelf and ephemerally in the off-shore regions. However, aragonite undersaturation (acidification) might become one of the biggest problems for the Antarctic marine ecosystem by affecting almost the entire SO. Direct and indirect impacts of various environmental changes to the three major habitats, sea-ice, pelagic and benthos and their biota are complex. The areas affected by environmental stressors range from 33% of the SO for a single stressor, 11% for two and 2% for three, to <1% for four and five overlapping factors. In the future, areas expected to be affected by 2 and 3 overlapping factors are equally large, including potential iceberg changes, and together cover almost 86% of the SO ecosystem. © 2014 John Wiley & Sons Ltd. Source

Donovan A.R.,University of Cambridge | Donovan A.R.,University of Sheffield | Oppenheimer C.,University of Cambridge | Bravo M.,Scott Polar Research Institute
Applied Geography | Year: 2012

This paper documents the evolution of hazard maps on the island of Montserrat, where volcanic activity has continued episodically since 1995. The paper argues that public participation can constitute political empathy, particularly where livelihoods are at stake, and can bring some order to the contested boundary between scientific risk assessment and its uptake by policymakers. This highlights that both bottom-up and top-down approaches to risk assessment are important, but also that the detailed structures within government and within science can be critical in ensuring the safety of populations, and that understanding the intricacies of local realisations of the science-policy interface is crucial to managing future hazard events. Systems that are responsive to public opinion and are transparent are more likely to win public trust. This is an important area for geographical studies combining human and physical methods, not solely in the development of maps but in the framing of their production and use. © 2012 Elsevier Ltd. Source

Hulbe C.L.,Portland State University | Wang W.,NASA | Ommanney S.,Scott Polar Research Institute
Journal of Glaciology | Year: 2011

Women's history in glaciology extends as far back in time as the discipline itself, although their contributions to the scientific discourse have for all of that history been constrained by the sociopolitical contexts of the times. The first Journal of Glaciology paper authored by a woman appeared in 1948, within a year of the founding of the Journal, but it was not until the 1980s that women produced more than a few percent of Journal and Annals of Glaciology papers. Here international perspectives on women's participation in the sciences are presented in order to establish an economic and sociopolitical context for stories of women 'pioneers' in glaciology and a frame in which to discuss women's persistent under-representation relative to men. We find that the experiences of individual glaciologists mirror women's experiences in higher education and the sciences as a whole. The existence of both positive and negative trends in women's participation in the sciences suggests caution in the interpretation of recent positive trends for women's participation in glaciology. Source

Gowan E.J.,University of Stockholm | Gowan E.J.,Bolin Center for Climate Research | Gowan E.J.,Australian National University | Tregoning P.,Australian National University | And 7 more authors.
Geoscientific Model Development | Year: 2016

We describe a program that produces paleo-ice sheet reconstructions using an assumption of steady-state, perfectly plastic ice flow behaviour. It incorporates three input parameters: ice margin, basal shear stress and basal topography. Though it is unlikely that paleo-ice sheets were ever in complete steady-state conditions, this method can produce an ice sheet without relying on complicated and unconstrained parameters such as climate and ice dynamics. This makes it advantageous to use in glacial-isostatic adjustment ice sheet modelling, which are often used as input parameters in global climate modelling simulations. We test this program by applying it to the modern Greenland Ice Sheet and Last Glacial Maximum Barents Sea Ice Sheet and demonstrate the optimal parameters that balance computational time and accuracy. © 2016 Author(s). Source

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