50 research outputs found

    Long-term soil organic carbon changes after cropland conversion to grazed grassland in Southern Sweden

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    There is growing awareness of the potential value of agricultural land for climate change mitigation. In Sweden, cropland areas have decreased by approximately 30% over recent decades, creating opportunities for these former croplands to be managed for climate change mitigation by increasing soil organic carbon (SOC) stocks. One potential land-use change is conversion of cropland to grazed grasslands, but the long-term effect of such change in management is not well understood and likely varies with soil type and site-specific conditions. Through sampling of mineral and peatland soils within a 75-year chronosequence of land converted from crop production to grazed grassland, we assessed how time since conversion, catenary position, and soil depth affected SOC storage. The SOC stocks calculated at an equivalent soil or ash mass increased through time since conversion in mineral soils at all topographic positions, at a rate of similar to 0.65% year(-1). Soils at low topographic positions gained the most carbon. Peat SOC stock gains after conversion were large, but only marginally significant and only when calculated at an equivalent ash mass. We conclude that the conversion of mineral soil to grazed grassland promotes SOC accumulation at our sites, but climate change mitigation potential would need to be evaluated through a full greenhouse gas balance

    Recognizing Agricultural Headwaters as Critical Ecosystems

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    Agricultural headwaters are positioned at the interface between terrestrial and aquatic ecosystems and, therefore, at the margins of scientific disciplines. They are deemed devoid of biodiversity and too polluted by ecologists, overlooked by hydrologists, and are perceived as a nuisance by landowners and water authorities. While agricultural streams are widespread and represent a major habitat in terms of stream length, they remain understudied and thereby undervalued. Agricultural headwater streams are significantly modified and polluted but at the same time are the critical linkages among land, air, and water ecosystems. They exhibit the largest variation in streamflow, water quality, and greenhouse gas emission with cascading effects on the entire stream networks, yet they are underrepresented in monitoring, remediation, and restoration. Therefore, we call for more intense efforts to characterize and understand the inherent variability and sensitivity of these ecosystems to global change drivers through scientific and regulatory monitoring and to improve their ecosystem conditions and functions through purposeful and evidence-based remediation

    Data for wetlandscapes and their changes around the world

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    Geography and associated hydrological, hydroclimate and land-use conditions and their changes determine the states and dynamics of wetlands and their ecosystem services. The influences of these controls are not limited to just the local scale of each individual wetland but extend over larger landscape areas that integrate multiple wetlands and their total hydrological catchment – the wetlandscape. However, the data and knowledge of conditions and changes over entire wetlandscapes are still scarce, limiting the capacity to accurately understand and manage critical wetland ecosystems and their services under global change. We present a new Wetlandscape Change Information Database (WetCID), consisting of geographic, hydrological, hydroclimate and land-use information and data for 27 wetlandscapes around the world. This combines survey-based local information with geographic shapefiles and gridded datasets of large-scale hydroclimate and land-use conditions and their changes over whole wetlandscapes. Temporally, WetCID contains 30-year time series of data for mean monthly precipitation and temperature and annual land-use conditions. The survey-based site information includes local knowledge on the wetlands, hydrology, hydroclimate and land uses within each wetlandscape and on the availability and accessibility of associated local data. This novel database (available through PANGAEA https://doi.org/10.1594/PANGAEA.907398; Ghajarnia et al., 2019) can support site assessments; cross-regional comparisons; and scenario analyses of the roles and impacts of land use, hydroclimatic and wetland conditions, and changes in whole-wetlandscape functions and ecosystem services

    Pathways from research to sustainable development: insights from ten research projects in sustainability and resilience

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    Drawing on collective experience from ten collaborative research projects focused on the Global South, we identify three major challenges that impede the translation of research on sustainability and resilience into better-informed choices by individuals and policy-makers that in turn can support transformation to a sustainable future. The three challenges comprise: (i) converting knowledge produced during research projects into successful knowledge application; (ii) scaling up knowledge in time when research projects are short-term and potential impacts are long-term; and (iii) scaling up knowledge across space, from local research sites to larger-scale or even global impact. Some potential pathways for funding agencies to overcome these challenges include providing targeted prolonged funding for dissemination and outreach, and facilitating collaboration and coordination across different sites, research teams, and partner organizations. By systematically documenting these challenges, we hope to pave the way for further innovations in the research cycle

    Priorities and interactions of Sustainable Development Goals (SDGs) with focus on wetlands

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    Wetlands are often vital physical and social components of a country's natural capital, as well as providers of ecosystem services to local and national communities. We performed a network analysis to prioritize Sustainable Development Goal (SDG) targets for sustainable development in iconic wetlands and wetlandscapes around the world. The analysis was based on the information and perceptions on 45 wetlandscapes worldwide by 49 wetland researchers of the GlobalWetland Ecohydrological Network (GWEN). We identified three 2030 Agenda targets of high priority across the wetlandscapes needed to achieve sustainable development: Target 6.3-'Improve water quality'; 2.4-'Sustainable food production'; and 12.2-'Sustainable management of resources'. Moreover, we found specific feedback mechanisms and synergies between SDG targets in the context of wetlands. The most consistent reinforcing interactions were the influence of Target 12.2 on 8.4-'Efficient resource consumption'; and that of Target 6.3 on 12.2. The wetlandscapes could be differentiated in four bundles of distinctive priority SDG-targets: 'Basic human needs', 'Sustainable tourism', 'Environmental impact in urban wetlands', and 'Improving and conserving environment'. In general, we find that the SDG groups, targets, and interactions stress that maintaining good water quality and a 'wise use' of wetlandscapes are vital to attaining sustainable development within these sensitive ecosystems. © 2019 by the authors

    Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans

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    Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in 25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16 regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP, while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium (LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region. Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa, an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent signals within the same regio

    Imagining an Imperial Modernity: Universities and the West African Roots of Colonial Development

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    © 2016 Informa UK Limited, trading as Taylor & Francis GroupThis article takes the formation and work of the ‘Elliot’ Commission on Higher Education in West Africa (1943–45) to reconsider the roots of British colonial development. Late colonial universities were major development projects, although they have rarely been considered as such. Focusing particularly on the Nigerian experience and the controversy over Yaba Higher College (founded 1934), the article contends that late colonial plans for universities were not produced in Britain and then exported to West African colonies. Rather, they were formed through interactions between agendas and ideas with roots in West Africa, Britain and elsewhere. These debates exhibited asymmetries of power but produced some consensus about university development. African and British actors conceptualised modern education by combining their local concerns with a variety of supra-local geographical frames for development, which included the British Empire and the individual colony. The British Empire did not in this case forestall development, but shaped the ways in which development was conceived

    Organic carbon stabilization in temperate paddy fields and adjacent semi-natural forests along a soil age gradient

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    Rice paddy soils have high organic carbon (OC) storage potential, but predicting OC stocks in these soils is difficult due to the complex OC stabilization mechanisms under fluctuating redox conditions. Especially in temperate climates, these mechanisms remain understudied and comparisons to OC stocks under natural vegetation are scarce. Semi-natural forests could have similar or higher OC inputs than rice paddies, but in the latter mineralization under anoxic conditions and interactions between OC and redox-sensitive minerals (in particular Fe oxyhydroxides, hereafter referred to as Fe oxides) could promote OC stabilization. Moreover, managementinduced soil redox cycling in rice paddies can interact with pre-existing pedogenetic differences of soils having different degrees of evolution. To disentangle these drivers of soil OC stocks, we focused on a soil age gradient in Northern Italy with a long (30 + years) history of rice cultivation and remnant semi-natural forests. Irrespective of soil age, soils under semi-natural forest and paddy land-use showed comparable OC stocks. While, in topsoil, stocks of crystalline Fe and short-ranged Fe and Al oxides did not differ between land-uses, under paddy management more OC was found in the mineral-associated fraction. This hints to a stronger redox-driven OC stabilization in the paddy topsoil compared to semi-natural forest soils that might compensate for the presumed lower OC inputs under rice cropping. Despite the higher clay contents over the whole profile and more crystalline pedogenetic Fe stocks in the topsoil in older soils, OC stocks were higher in the younger soils, in particular in the 50-70 cm layer, where short-range ordered pedogenetic oxides were also more abundant. These patterns might be explained by differences in hydrological flows responsible for the translocation of Fe and dissolved OC to the subsoil, preferentially in the younger, coarse-textured soils. Taken together, these results indicate the importance of the complex interplay between redox-cycling affected by paddy-management and soilage related hydrological properties
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