1,298 publications from this institution
Mobilization of soil/sediment organic carbon into inland waters constitutes a substantial, but poorly-constrained, component of the global carbon cycle. Radiocarbon (14C) analysis has proven a valuable tool in tracing the sources and fate of mobilized carbon, but aquatic 14C studies in permafrost regions rarely detect 'old' carbon (assimilated from the atmosphere into plants and soil prior to AD1950). The emission of greenhouse gases derived from old carbon by aquatic systems may indicate that carbon sequestered prior to AD1950 is being destabilized, thus contributing to the 'permafrost carbon feedback' (PCF). Here, we measure directly the 14C content of aquatic CO2, alongside dissolved organic carbon, in headwater systems of the western Canadian Arctic - the first such concurrent measurements in the Arctic. Age distribution analysis indicates that the age of mobilized aquatic carbon increased significantly during the 2014 snow-free season as the active layer deepened. This increase in age was more pronounced in DOC, rising from 101-228 years before sampling date (a 120%-125% increase) compared to CO2, which rose from 92-151 years before sampling date (a 59%-63% increase). 'Pre-industrial' aged carbon (assimilated prior to ∼AD1750) comprised 15%-40% of the total aquatic carbon fluxes, demonstrating the prevalence of old carbon to Arctic headwaters. Although the presence of this old carbon is not necessarily indicative of a net positive PCF, we provide an approach and baseline data which can be used for future assessment of the PCF.
Will the rain wash away our soil organic carbon under future climate change?
This article examines the career of journalist Norma Fields, who worked for the Northeast (MS) Daily Journal for twenty-four years (1964–1988), first as a part-time stringer and then as a political correspondent covering the state capitol in Jackson. The research featured herein analyzes the type of stories she covered, the content of her weekly political column, her style of reporting, and how each may have influenced state policy. The findings illuminate Fields’s influence as the first woman to cover the Mississippi state capitol on the perceptions of women journalists held by members of the state government. Fields’s story adds to a growing body of literature in the areas of women’s history and journalism history, which has omitted the experiences of women political correspondents at the state level, and this article describes a brand of journalism and set of professional experiences that challenged the status quo.
There is a growing consensus that projected levels of meat demand are unsustainable, so we will need to eat less meat in the future, as well as tackling waste in the food system. Since ruminants produce large quantities of methane through enteric fermentation, it has been suggested that ruminants should be the primary target for livestock product reductuion, but there is a strong case to instead target reductions in monogastric livestock production, since monogastrics consume potentially human-ediblke products, wheras ruminants are able to consume products (grass) that cannot be consumed by humans, and are the most efficient means of producing human food on land unsuitable for crops. The livestock sector and grasslands play a major role in climate change, from both global and European perspectives. This is illustrated by data on the current status of emissions from the livestock sector in combination wirh projections of emissions from the sector to 2050. There is, however, also a large climate change mitigation potential in the livestock/grassland sector, both via supply-side measures and demand-side measures. Here we provide evidence fromt the literature showing that the grazing lands that support ruminant production in Europe are important for carbon and ntrogen cycling, and for underpinning a range of other ecosystem services, adding further weight to the case to retain pasture raised ruminants as a part of future food systems. This will need to be done, however, in the context of reduced overall consumption of livestock products. Indeed, reduced livestock product consumption could be seen as the enabling condition that allows pasture-fed ruminants tot ake their role in future food production systems. If more of human dietary requirements were met through vegetal matter, which is more efficient in terms of land, greehoude gases, water and other resources, there is more headroomin the food system to consider a range of production systems to deliver livestock products to human diets. Pasture-fed ruminants, with high environmental and welfare status, could play a central role in future food systems, in delivering food security and in protecting the ecosystem services provided by grasslands.
Abstract In this paper we estimate the European potential for carbon mitigation of no‐till farming using results from European tillage experiments. Our calculations suggest some potential in terms of (a) reduced agricultural fossil fuel emissions, and (b) increased soil carbon sequestration. We estimate that 100% conversion to no‐till farming would be likely to sequester about 23 Tg C y –1 in the European Union or about 43 Tg C y –1 in the wider Europe (excluding the former Soviet Union). In addition, up to 3.2 Tg C y –1 could be saved in agricultural fossil fuel emissions. Compared to estimates of the potential for carbon sequestration of other carbon mitigation options, no‐till agriculture shows nearly twice the potential of scenarios whereby soils are amended with organic materials. Our calculations suggest that 100% conversion to no‐till agriculture in Europe could mitigate all fossil fuel‐carbon emissions from agriculture in Europe. However, this is equivalent to only about 4.1% of total anthropogenic CO 2 ‐carbon produced annually in Europe (excluding the former Soviet Union) which in turn is equivalent to about 0.8% of global annual anthropogenic CO 2 ‐carbon emissions.
Summary For the 70th Anniversary of the establishment of the British Society of Soil Science, this short paper explores the idea that research on soil organic matter has remained a central theme within soil science over the past 70 years, albeit with changing emphasis and application. The number of publications on soil organic matter has increased greatly in recent decades; for example, there were almost 35 000 journal papers with this theme in the decade 2007–2016. Several topics in research on soil organic matter, such as soil fertility, have endured for a number of decades, with publications found on soil organic matter and fertility in the decade 1947–1956. A search with other keywords occurring with soil, such as climate change, biodiversity, fertility, quality, health and security, showed that several topics did not appear before the 1970s and 1980s, but since then the sub‐topics and applications have diversified. Carbon is a keyword that has become more associated with publications on soil organic matter; carbon is in over half of soil organic matter publications of the last decade. A closer examination of research on agricultural soil carbon sequestration since 1990 reveals that the focus of papers in the literature has changed over this period. A closer examination of papers on modelling shows that the next generation of soil organic matter models is developing from pseudo first‐order decay models using conceptual pools and prescribed controls of turnover time to vertically resolved, microbially explicit models representing mineral surface and plant interactions. Given its higher policy profile during the last 2 years, research on soil organic matter and soil carbon sequestration is predicted to have a bright future. Highlights The number of publications on soil organic matter has increased greatly in recent decades. Soil fertility research has endured for many decades, whereas other topics have diversified. Soil organic matter has been increasingly associated with carbon, which has changed the focus of papers since 1990. Expanding policy attention to soil organic matter research during the last 2 years suggests a bright future.