drinkcello8

In flooded paddy soils, some metal reducers are also capable of nitrogen (N) fixation, which is essential in ensuring a reliable N-supply for rice growth. Microbial iron [Fe(III)] reduction is an important biogeochemical process that can be stimulated by ferrihydrite amendment to paddy soil. Therefore, this study aimed to investigate the abundance and succession of the N2-fixing bacterial community in ferrihydrite enriched paddy soils collected from Hunan (HN) and Sichuan (SC) provinces, China. The relationship between the N2-fixing bacterial community and Fe(III) reduction was also assessed. When compared with the control treatment, ferrihydrite enrichment significantly enhanced nitrogenase (nifH) gene abundance by 8.05 × 105 to 4.45 × 106 copies g-1 soil during the 40-day flooding of HN soil, while nifH gene abundance in SC soil was remarkably increased by 5.90 × 107 to 9.56 × 107 copies g-1 soil during day 1 to 5 in response to ferrihydrite amendment. The relative abundance of N2-fixing bacteria peaked on day 5 (21.5% in HN soil and 5.4% in SC soil) and gradually decreased to a stable abundance after day 20. Remarkable increases in relative abundance of N2-fixing bacteria during the first 10 days of flooding were detected in both soils with ferrihydrite enrichment, whereas little difference was found after day 10 of flooding. During the early stage of flooding, the Shannon and Simpson indexes of N2-fixing bacteria with ferrihydrite enrichment were significantly decreased, and the community structure changed greatly. Most N2-fixing bacteria in ferrihydrite enriched paddy soils were phylogenetically related to the order Clostridiales, with some of those potentially capable of Fe(III) reduction. The community succession of N2-fixing bacteria closely correlated with Fe(III) reduction. Thus, improving N2-fixation via stimulation of Fe(III) reduction might aid in the reduction of N-fertilizer application to paddy field. V.Monitoring freshwater and wetland systems and their response to stressors of natural or anthropogenic origin is critical for ecosystem conservation. A multi-temporal set of 87 images, acquired by Sentinel-2 satellites over three years (2016-2018), provided quantitative information for assessing the temporal evolution of key ecosystem variables in the perialpine Lake Mezzola (northern Italy), which has suffered from the impacts of a massive landslide that took place upstream of the lake basin in summer 2017. Sentinel-2 derived products revealed an increase in lake turbidity triggered by the landslide that amounted to twice the average values scored in the years preceding and following the event. Hotspots of turbidity within the lake were in particular highlighted. Moreover, both submerged and riparian vegetation showed harmful impacts due to sediment deposition. A partial loss of submerged macrophyte cover was found, with delayed growth and a possible community shift in favor of species adapted to inorganic substrates. Satellite-derived seasonal dynamics showed that exceptional sediment load can overwrite climatic factors in controlling phenology of riparian reed beds, resulting in two consecutive years with shorter than normal growing season and roughly 20% drop in productivity, according to spectral proxies. Compared to 2016, senescence came earlier by around 20 days on average in 2017 season, and green-up was delayed by up to 50 days (20 days, on average) in 2018, following the landslide. The approach presented could be easily implemented for continuous monitoring of similar ecosystems subject to external pressures with periods of high sediment loads. Constructed wetlands are effective at removing nitrate, one of the major pollutants in aquatic ecosystems. In this study, nitrogen and oxygen isotopes (δ15N and δ18O) were used to determine the sources and transformations of nitrate (NO3-), evaluate isotopic fractionation, and estimate nitrogen (N) removal in the Xixi Wetland, a large semi-constructed wetland in East China. The values of δ15N and δ18O in the Xixi Wetland ranged from +3.7‰ to +19.0‰ and from +1.1‰ to +13.7‰, respectively. The main NO3- sources included sewage/manure, chemical fertiliser and soil nitrogen. Anthropogenic sources became more significant in the Xixi Westland, especially in autumn, as the increased number of tourists resulted in increased sewage/manure input. The results indicated that nitrification and denitrification were the key processes governing N transformations. The monthly variations in the NO3- concentrations and δ15N values indicated that denitrification was strong from spring to autumn in the Xixi Wetland. check details Based on measurements of the natural abundance of δ15N, it was determined that the enrichment factors (ε) of the Xixi Wetland ranged from -0.7‰ to -1.0‰, and were smaller than those in a laboratory denitrification experiment (-1.6‰). In this study, denitrification, nitrification, and assimilation in plants/microbes were responsible for the low enrichment factors. Additionally, the amount of N removal via denitrification varied widely, from 22 kg N·ha-1 yr-1 to 798 kg N·ha-1 yr-1; thus, significant potential for N removal was found in the Xixi Wetland. Psychological frameworks are often used to investigate the mechanisms involved with our affinity towards, and connection with nature—such as the Biophilia Hypothesis and Nature Connectedness. Recent revelations from microbiome science suggest that animal behaviour can be strongly influenced by the host's microbiome—for example, via the bidirectional communication properties of the gut-brain axis. Here, we build on this theory to hypothesise that a microbially-influenced mechanism could also contribute to the human biophilic drive – the tendency for humans to affiliate and connect with nature. Humans may be at an evolutionary advantage through health-regulating exchange of environmental microbiota, which in turn could influence our nature affinity. We present a conceptual model for microbially-influenced nature affinity, calling it the Lovebug Effect. We present an overview of the potential mechanistic pathways involved in the Lovebug Effect, and consider its dependence on the hologenome concept of evolution, direct behavioural manipulation, and host-microbiota associated phenotypes independent of these concepts.