The interplay between event and background sedimentation and the origin of fossil‐rich carbonate concretions: a case study in Permian rocks of the Paraná Basin,Brazil

The Permian Serra Alta Formation was generated under transgressive conditions within a large, calm epeiric sea. A monotonous succession of ‘barren’, massive mudstones deposited under oxygen‐deficient conditions (mainly below storm wave base) is the main lithofacies of this unit. Fossils are generally rare and diluted in the matrix, but certain intervals contain shell‐rich concentrations with well‐preserved, closed articulated bivalves, mixed with shells and comminuted debris with variable quality of preservation, all encased in carbonate concretions. Two main scenarios may account for the origin of these bivalve‐rich concretions (i.e. unique events in sea‐water chemistry or unique burial‐starvation couplets). Sedimentological and taphonomic information indicates that the final deposition of the original shell‐rich mudstone intervals was probably tied to episodic influx of fine‐grained sediments in distal settings. Moderate bioturbation is also recorded suggesting low rates of sedimentation prior to early diagenesis. Hence, the fossil concentrations in concretions were formed due to the interplay of event and background sedimentation. These are internally simple concentrations with complex depositional histories. The concretion‐bearing beds are not randomly distributed in the Serra Alta Formation. Rather, they are found in the sparsely fossiliferous offshore deposits of the basal to intermediate portions of the unit. Thus, the concretionary mudstone beds and associated deposits are preserved in particular intervals and can be tracked for kilometres. This indicates that the conditions essential for concretion development existed only at particular stratigraphical intervals. Finally, our study strongly corroborates the idea that concretions are critical sources of sedimentological, taphonomic and stratigraphical information.     

Toward an Overall Analytical Framework for the Integrated Sustainability Assessment of the Production and Supply of Raw Materials and Primary Energy Carriers

The sustainable production and supply of raw materials (“nonenergy raw materials”) and primary energy carriers (“energy raw materials”) is a core element of many policies. The natural resource base for their production and supply, and the access thereto, are limited. Moreover, raw material supply is high on environmental and social impact agendas as well. A broad, quantitative framework that supports decision makers is recommended so as to make use of raw materials and primary energy carriers more sustainably. First, this article proposes a holistic classification of raw materials and primary energy carriers. This is an essential prerequisite for developing an integrated sustainability assessment framework (ISAF). Indeed, frequently, only a subset of raw materials and primary energy carriers are considered in terms of their source, sector, or final application. Here, 85 raw materials and 30 primary energy carriers overall are identified and grouped into seven and five subgroups, respectively. Next, this article proposes a quantitative ISAF for the production and supply of raw materials and primary energy carriers, covering all the sustainability pillars. With the goal of comprehensiveness, the proposed ISAF integrates sustainability issues that have been covered and modeled in quite different quantitative frameworks: ecosystem services; classical life cycle assessment (LCA); social LCA; resource criticality assessment; and particular international concerns (e.g., conflict minerals assessment). The resulting four areas of concerns (i.e., environmental, technical, economic, and social/societal) are grouped into ten specific sustainability concerns. Finally, these concerns are quantified through 15 indicators, enabling the quantitative sustainability assessment of the production and supply of raw materials and primary energy carriers.     

The Contribution of Agriculture,Forestry and other Land Use activities to Global Warming, 1990–2012

We refine the information available through the IPCC AR5 with regard to recent trends in global GHG emissions from agriculture, forestry and other land uses (AFOLU), including global emission updates to 2012. Using all three available AFOLU datasets employed for analysis in the IPCC AR5, rather than just one as done in the IPCC AR5 WGIII Summary for Policy Makers, our analyses point to a down‐revision of global AFOLU shares of total anthropogenic emissions, while providing important additional information on subsectoral trends. Our findings confirm that the share of AFOLU emissions to the anthropogenic total declined over time. They indicate a decadal average of 28.7 ± 1.5% in the 1990s and 23.6 ± 2.1% in the 2000s and an annual value of 21.2 ± 1.5% in 2010. The IPCC AR5 had indicated a 24% share in 2010. In contrast to previous decades, when emissions from land use (land use, land use change and forestry, including deforestation) were significantly larger than those from agriculture (crop and livestock production), in 2010 agriculture was the larger component, contributing 11.2 ± 0.4% of total GHG emissions, compared to 10.0 ± 1.2% of the land use sector. Deforestation was responsible for only 8% of total anthropogenic emissions in 2010, compared to 12% in the 1990s. Since 2010, the last year assessed by the IPCC AR5, new FAO estimates indicate that land use emissions have remained stable, at about 4.8 Gt CO₂ eq yr^?1 in 2012. Emissions minus removals have also remained stable, at 3.2 Gt CO₂ eq yr^?1 in 2012. By contrast, agriculture emissions have continued to grow, at roughly 1% annually, and remained larger than the land use sector, reaching 5.4 Gt CO₂ eq yr^?1 in 2012. These results are useful to further inform the current climate policy debate on land use, suggesting that more efforts and resources should be directed to further explore options for mitigation in agriculture, much in line with the large efforts devoted to REDD+ in the past decade.     

The composition of arbuscular mycorrhizal fungal communities in the roots of a ruderal forb is not related to the forest fragmentation process

Land‐use changes and forest fragmentation have strong impact on biodiversity. However, little is known about the influence of new landscape configurations on arbuscular mycorrhizal fungal (AMF) community composition. We used 454 pyrosequencing to assess AMF diversity in plant roots from a fragmented forest. We detected 59 virtual taxa (VT; phylogenetically defined operational taxonomic units) of AMF – including 10 new VT – in the roots of Euphorbia acerensis. AMF communities were mainly composed of members of family Glomeraceae and were similar throughout the fragmented landscape, despite variation in forest fragment size (i.e. small, medium and large) and isolation (i.e. varying pairwise distances). AMF communities in forest fragments were phylogenetically clustered compared with the global, but not regional and local AMF taxon pools. This indicates that non‐random community assembly processes possibly related to dispersal limitation at a large scale, rather than habitat filtering or biotic interactions, may be important in structuring the AMF communities. In this system, forest fragmentation did not appear to influence AMF community composition in the roots of the ruderal plant. Whether this is true for AMF communities in soil and the roots of other ecological groups of host plants or in other habitats deserves further study.