Fournierernst3272

Those microbial responses to biochar addition were higher in 60-year-old soil relative to 20-year-old soil, leading to a higher enhancement of N retention and mitigation of N leaching. Soil pH was the prime factor that influenced soil microbes, and it strongly correlated with microbial biomass, enzyme activity, the relative abundance of dominant phyla and α-diversity indices. Therefore, the enhancement of microbial biomass, activity and shifts of bacterial community composition related to N cycling in response to biochar additions that increased the soil pH could be an important mechanism to better understand the biochar-induced N leaching mitigation and N retention enhancement in tea soils under different plantation ages.Forests play a key role in global carbon cycling and sequestration. However, the potential for carbon drawdown is affected by forest fragmentation and resulting changes in microclimate, nutrient inputs, disturbance and productivity near edges. Up to 20% of the global forested area lies within 100 m of an edge and, even in temperate forests, knowledge on how edge conditions affect carbon stocks and how far this influence penetrates into forest interiors is scarce. Here we studied carbon stocks in the aboveground biomass, forest floor and the mineral topsoil in 225 plots in deciduous forest edges across Europe and tested the impact of macroclimate, nitrogen deposition and smaller-grained drivers (e.g. microclimate) on these stocks. Total carbon and carbon in the aboveground biomass stock were on average 39% and 95% higher at the forest edge than 100 m into the interior. The increase in the aboveground biomass stock close to the edge was mainly related to enhanced nitrogen deposition. No edge influence was found for stocks in the mineral topsoil. Edge-to-interior gradients in forest floor carbon changed across latitude carbon stocks in the forest floor were higher near the edge in southern Europe. Forest floor carbon decreased with increasing litter quality (i.e. high decomposition rate) and decreasing plant area index, whereas higher soil temperatures negatively affected the mineral topsoil carbon. Based on high-resolution forest fragmentation maps, we estimate that the additional carbon stored in deciduous forest edges across Europe amounts to not less than 183 Tg carbon, which is equivalent to the storage capacity of 1 million ha of additional forest. This study underpins the importance of including edge influences when quantifying the carbon stocks in temperate forests and stresses the importance of preserving natural forest edges and small forest patches with a high edge-to-interior surface area.Nickel (Ni) is one of the most essential trace elements in the anaerobic digestion system. In this study, green chelating agent Ethylenediamine-N, N'-disuccinic acid (EDDS), common chelating agents with low biodegradability nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA) were respectively used as ligands of Ni (II) to inspect the feasibility of enhancing methane production and reducing Ni dosage. selleck chemicals llc In practice, continuous stirred-tank reactors (37 °C, 120 rpm) were operated with a mixture of pig manure and food waste as the substrate, and were supplied with extra Ni in the form of Ni (II) (0, 2.5, and 5.0 mg/L) or chelator‑nickel (EDDS-Ni, NTA-Ni and EDTA-Ni) complexes (2.5 mg/L). The results showed that compared with that of adding Ni (2.5 mg/L) individually, the methane production increased of 23.34%, 31.26% and 16.07% with the addition of EDDS-Ni, NTA-Ni and EDTA-Ni complexes (2.5 mg/L), respectively. Accompanying with that, the EDDS-Ni and NTA-Ni supplementations both significantly increased the F430 concentration of 28% and 36% on the day of peak methane production (day five). The BCR sequential extraction analysis indicated that the sum of Ni in water soluble and exchangeable fractions after digestion were increased of 43.28%, 39.41%, and 24.29%, respectively. Further, the acid-volatile sulfide (AVS) and the simultaneously extracted nickels (SEMNi) content in sediments confirmed that the chelator‑nickel improved Ni bioavailability due to dissolution of nickel ions from their sulfides. This study demonstrated that the addition of chelator-Ni complexes was a practicable method to enhance methane production and reduced Ni dosage.High levels of dissolved arsenic (As) have been reported in many rivers running though the Tibetan Plateau (TP), the "Water Tower of Asia". However, the source, spatiotemporal variations, and geochemical behavior of dissolved As in these rivers remain poorly understood. In this study, hot spring, river water, and suspended particulate material samples collected from the Yarlung Tsangpo River (YTR) (upper reaches of the Brahmaputra River) system in 2017 and 2018 were analyzed. Spatial results shown that the upper reaches of YTR (Zone I) have comparatively high levels of dissolved As ([As]dissolved mean 31.7 μg/L; 4.7-81.6 μg/L; n = 16), while the tributaries of the lower reaches (Zone II) have relatively low levels (mean 0.54 μg/L; 0.11-1.3 μg/L; n = 7). Seasonal results shown that the high [As]dissolved (6.1-22.4 μg/L) were found in September to June and low [As]dissolved (1.4-3.7 μg/L) were observed in July to August. Geothermal water is suspected as the main source of the elevated As levels in YTR due to the extremely high [As]dissolved in hot springs (1.13-9.76 mg/L) and abundance of geothermal systems throughout TP. However, the seasonal results suggested that weathering of As-containing rocks and minerals is also a key factor affecting the [As]dissolved in the river water in July to August (wet-season). Natural attenuation of As in main channel is dominated by dilution process due to the lower As concentrations in tributaries, but mostly occurred by both dilution and adsorption (or co-precipitation) processes in tributaries. This work highlights that the weathering process may have an important contribution to the dissolved As in the river waters in wet-season, and the geochemical behavior of As is largely transported conservatively in the main channel and relative non-conservatively in the tributaries in YTR system.