http://www.sciencedirect.com/science/article/pii/S0048969719345917 Baseline mobile surveys of methane sources using vehicle-mounted instruments have been performed in the Fylde and Ryedale regions of Northern England over the 2016 - 19 period around proposed unconventional (shale) gas extraction sites. The aim was to identify and characterise methane sources ahead of hydraulically fractured shale gas extraction in the area around drilling sites. This allows a potential additional source of emissions to atmosphere to be readily distinguished from adjacent sources, should gas production take place. The surveys have used ethane:methane (C2:C1) ratios to separate combustion, thermogenic gas and biogenic 13 sources. Sample collection of source plumes followed by high precision δ C analysis of methane, to separate and isotopically characterise sources, adds additional biogenic source distinction between active and closed landfills, and ruminant eructations from manure. The surveys show that both drill sites and adjacent fixed monitoring sites have cow barns and gas network pipeline leaks as sources of methane within a 1 km range. These two sources are readily separated by isotopes 13 (δ C of -67 to -58‰ for barns, compared to -43 to -39‰ for gas leaks), and ethane:methane ratios (<0.001 for barns, compared to >0.05 for gas leaks). Under a well-mixed daytime atmospheric boundary layer these sources are generally detectable as above baselin e elevations up to 100 mdownwind fo r gas leaks and up to 500 mdownwind for populated cow barns. It is considered that careful analysis of these proxies for unconventional production gas, if and when available, will allow any fugitive emissions from operations to be distinguished from surrounding sources.

Lu, G.-Y., Imai, H., Ikeya, K., Sumida, H., Watanabe, A., 2020. Black carbon as a significant component of aromatic carbon in surface soils and its importance is enhanced in volcanic ash soil profiles. Organic Geochemistry 140, 103957.

http://www.sciencedirect.com/science/article/pii/S0146638019301949 Black carbon (BC) constitutes a refractory carbon (C) pool in soil and other environments. Estimating the amount and dynamics of BC in soil is important in terms of the global C cycle. The goal of this study was to characterize the contribution of BC to total and aromatic C in a variety of soils using the benzene 13 polycarboxylic acid (BPCA) method and solid-state C nuclear magnetic resonance (NMR) spectroscopy. Thirteen A-/Ap (plowed layer)-horizon soils that belong to widely distributed soil series (Humic Andosols, Dystric Cambisols, Gleyic Cambisols, Eutric Fluvisols, and Dystric Planosols) under typical land uses (forest, grassland, upland field, and paddy field) in Japan and two Andosol profiles were analyzed. Three humic acid samples including the green fraction, which contains 4,9-dihydroxyperylene-3,10-quinone (DHPQ) as a chromophore and has mycorrhiza as a possible source (referred to as Pg), were also subjected to the BPCA - 1 procedure. The BC content in the 13 A-/Ap-horizon soils was 0.3 - 53 gC kg or 5.7 - 48% of the total soil C (BC%). The BC content correlated positively with the total C content and with aromatic C content, while the relationship between BC% and soil order or land use was not clear. An analysis of Pg suggested the potential contribution of DHPQ to the yield of benzenehexacarboxylic acid in the BPCA method. The variations in BC content and C composition of two Andosol profiles indicated a greater stability of BC than the other types of C, including monocyclic aromatic C. The contribution of BC to aromatic C in their lower layers was estimated to be ca. 55 - 70% based on a regression equation when assuming that 70 - 90% of the BC was aromatic C.

Lu, K.- J., van 't Wout Hofland, N., Mor, E., Mutte, S., Abrahams, P., Kato, H., Vandepoele, K., Weijers, D., De Rybel, B., 2020. Evolution of vascular plants through redeployment of ancient developmental regulators. Proceedings of the National Academy of Sciences 117, 733-740.

https://doi.org/10.1073/pnas.1912470117 Significance: Vascular plants contribute to most of the food and feed production on earth and deliver heating and construction materials in the form of wood. Yet, we know very little about how nonvascular plants acquired vascular tissues during evolution. Here, we provide molecular insights into how 2 evolutionarily conserved transcription factors were redeployed to control proliferation of vascular cells. This is an example of a