Regenerated woody plants influence soil microbial communities in a subtropical forest

10 páginas.- 4 figuras.- 3 tablas.- referencias.- upplementary data to this article can be found online at https://doi. org/10.1016/j.apsoil.2023.104890Forests are critical for supporting multiple ecosystem services such as climate change mitigation. Microbial diversity in soil provides important functions to maintain and regenerate forest ecosystems, and yet a critical knowledge gap remains in identifying the linkage between attributes of regenerated woody plant (RWP) communities and the diversity patterns of soil microbial communities in subtropical plantations. Here, we investigated the changes in soil microbial communities and plant traits in a nine hectare Chinese fir (Cunninghamia lanceolata; CF) plantation to assess how non-planted RWP communities regulate soil bacterial and fungal diversity, and further explore the potential mechanisms that structure their interaction. Our study revealed that soil bacterial richness was positively associated with RWP richness, whereas soil fungal richness was negatively associated with RWP basal area. Meanwhile, RWP richness was positively correlated with ectomycorrhizal (ECM) fungal richness but negatively correlated with the richness of both pathogenic and saprotrophic fungi, suggesting that the RWP-fungal richness relationship was trophic guild-specific. Soil microbial community beta diversity (i.e., dissimilarity in community composition) was strongly coupled with both RWP beta diversity and the heterogeneity of RWP basal area. Our study highlights the importance of community-level RWP plant attributes for the regulation of microbial biodiversity in plantation systems, which should be considered in forest management programs in the future.This work was funded by the National Key Research and Development Program of China (2021YFD2201301 and 2022YFF1303003), the National Natural Science Foundation of China (U22A20612), and the Key Project of Jiangxi Province Natural Science Foundation of China (20224ACB205003).Peer reviewe

Litter and soil biodiversity jointly drive ecosystem functions

10 páginas.- 4 figuras.- 64 referencias.- Additional supporting information can be found online in the Supporting Information section at the end of this articleThe decomposition of litter and the supply of nutrients into and from the soil are two fundamental processes through which the above- and belowground world interact. Microbial biodiversity, and especially that of decomposers, plays a key role in these processes by helping litter decomposition. Yet the relative contribution of litter diversity and soil biodiversity in supporting multiple ecosystem services remains virtually unknown. Here we conducted a mesocosm experiment where leaf litter and soil biodiversity were manipulated to investigate their influence on plant productivity, litter decomposition, soil respiration, and enzymatic activity in the littersphere. We showed that both leaf litter diversity and soil microbial diversity (richness and community composition) independently contributed to explain multiple ecosystem functions. Fungal saprobes community composition was especially important for supporting ecosystem multifunctionality (EMF), plant production, litter decomposition, and activity of soil phosphatase when compared with bacteria or other fungal functional groups and litter species richness. Moreover, leaf litter diversity and soil microbial diversity exerted previously undescribed and significantly interactive effects on EMF and multiple individual ecosystem functions, such as litter decomposition and plant production. Together, our work provides experimental evidence supporting the independent and interactive roles of litter and belowground soil biodiversity to maintain ecosystem functions and multiple services.SEL acknowledges support from the National Natural Science Foundation of China (grant no. 32101491), fellowship of China Postdoctoral Science Foundation (2022T150375; 2021M701968), and Yunnan Science and Technology Talent and Platform Program (202105AG070002). GYZ acknowledges support from the Humbodlt Research Foundation. JP acknowledges support from the Ramon y Cajal program from the MICINN (RYC-2021-033454). ROH is funded by the Ramon y Cajal program of the MICINN (RYC-2017 22032), by the R & amp;D Project of the Ministry of Science and Innovation PID2019-106004RA-I00 funded by MCIN/AEI/10.13039/501100011033, and by the European Agricultural Fund for Rural Development (EAFRD) through the "Aid to operational groups of the European Association of Innovation (AEI) in terms of agricultural productivity and sustainability", Reference: GOPC-CA-20-0001. BKS acknowledge funding from Australian Research Council (DP210102081). MDB acknowledges support from the Spanish Ministry of Science and Innovation for the I+D+i project PID2020-115813RA-I00 and TED2021-130908B-C41 funded by MCIN/AEI/10.13039/501100011033. Open Access funding enabled and organized by Projekt DEAL.Peer reviewe

The global contribution of soil mosses to ecosystem services

Soil mosses are among the most widely distributed organisms on land. Experiments and observations suggest that they contribute to terrestrial soil biodiversity and function, yet their ecological contribution to soil has never been assessed globally under natural conditions. Here we conducted the most comprehensive global standardized field study to quantify how soil mosses influence 8 ecosystem services associated with 24 soil biodiversity and functional attributes across wide environmental gradients from all continents. We found that soil mosses are associated with greater carbon sequestration, pool sizes for key nutrients and organic matter decomposition rates but a lower proportion of soil-borne plant pathogens than unvegetated soils. Mosses are especially important for supporting multiple ecosystem services where vascular-plant cover is low. Globally, soil mosses potentially support 6.43 Gt more carbon in the soil layer than do bare soils. The amount of soil carbon associated with mosses is up to six times the annual global carbon emissions from any altered land use globally. The largest positive contribution of mosses to soils occurs under a high cover of mat and turf mosses, in less-productive ecosystems and on sandy and salty soils. Our results highlight the contribution of mosses to soil life and functions and the need to conserve these important organisms to support healthy soils.The study work associated with this paper was funded by a Large Research Grant from the British Ecological Society (no. LRB17\1019; MUSGONET). D.J.E. is supported by the Hermon Slade Foundation. M.D.-B. was supported by a Ramón y Cajal grant from the Spanish Ministry of Science and Innovation (RYC2018-025483-I), a project from the Spanish Ministry of Science and Innovation for the I + D + i (PID2020-115813RA-I00 funded by MCIN/AEI/10.13039/501100011033a) and a project PAIDI 2020 from the Junta de Andalucía (P20_00879). E.G. is supported by the European Research Council grant agreement 647038 (BIODESERT). M.B. is supported by a Ramón y Cajal grant from Spanish Ministry of Science (RYC2021-031797-I). A.d.l.R is supported by the AEI project PID2019-105469RB-C22. L.W. and Jianyong Wang are supported by the Program for Introducing Talents to Universities (B16011) and the Ministry of Education Innovation Team Development Plan (2013-373). The contributions of T.G. and T.U.N. were supported by the Research Program in Forest Biology, Ecology and Technology (P4-0107) and the research projects J4-3098 and J4-4547 of the Slovenian Research Agency. The contribution of P.B.R. was supported by the NSF Biological Integration Institutes grant DBI-2021898. J. Durán and A. Rodríguez acknowledge support from the FCT (2020.03670.CEECIND and SFRH/BDP/108913/2015, respectively), as well as from the MCTES, FSE, UE and the CFE (UIDB/04004/2021) research unit financed by FCT/MCTES through national funds (PIDDAC)

The Advancement of 7XXX Series Aluminum Alloys for Aircraft Structures: A Review

7XXX series aluminum alloys (Al 7XXX alloys) are widely used in bearing components, such as aircraft frame, spars and stringers, for their high specific strength, high specific stiffness, high toughness, excellent processing, and welding performance. Therefore, Al 7XXX alloys are the most important structural materials in aviation. In this present review, the development tendency and the main applications of Al 7XXX alloys for aircraft structures are introduced, and the existing problems are simply discussed. Also, the heat treatment processes for improving the properties are compared and analyzed. It is the most important measures that optimizing alloy composition and improving heat treatment process are to enhance the comprehensive properties of Al 7XXX alloys. Among the method, solid solution, quenching, and aging of Al 7XXX alloys are the most significant. We introduce the effects of the three methods on the properties, and forecast the development direction of the properties, compositions, and heat treatments and the solution to the corrosion prediction problem for the next generation of Al 7XXX alloys for aircraft structures. The next generation of Al 7XXX alloys should be higher strength, higher toughness, higher damage tolerance, higher hardenability, and better corrosion resistance. It is urgent requirements to develop or invent new heat treatment regime. We should construct a novel corrosion prediction model for Al 7XXX alloys via confirming the surface corrosion environments and selecting the accurate and reliable electrochemical measurements

Harmless disposal and resource utilization for secondary aluminum dross: A review

Secondary aluminum dross (SAD) is solid waste of primary aluminum dross extracted aluminum, which contains approximately 40–60 wt% alumina, 10–30 wt% aluminum nitride (AlN), 5–15 wt% salts and other components. The salts include sodium chloride, potassium chloride and fluorine salts. SAD has dual attributes as resource and pollutant. SAD landfill disposal has the disadvantages of occupying land, wasting resources, a high cost and great environmental impact. SAD utilization methods are currently pyrometallurgy and hydrometallurgy. In pyrometallurgy, AlN is oxidized and the salts are evaporated at high temperature. After mixing, molding and calcination, firebricks and ceramics can be manufactured from SAD. In hydrometallurgy, AlN is hydrolyzed and salts are dissolved in water. After dissolving, filtrating, precipitating, washing and calcination, γ-Al2O3 can be prepared from SAD. Resource consumption and emission from both utilization methods were assessed. A ton of magnesium aluminum titanate based ceramics by pyrometallurgy consumes 1043 kg raw materials and releases 69 kg of waste gas, 4.17 t of waste water and no solid waste. A ton of γ-Al2O3 by hydrometallurgy consumes 3389 kg raw materials and releases 111 kg of waste gas, 12.98 t of waste water and 267 kg of solid waste. Therefore, the resource consumption and emission of SAD utilization by pyrometallurgy is lower than that by hydrometallurgy. We should focus on reducing the emission of the three wastes from pyrometallurgy. We are sure that SAD can be utilized for glass ceramics by pyrometallurgy. AlN and salts can be transformed into alumina and glass phases at high temperature with no emission. We should clarify mechanisms for SAD composition adjustment to lower the glass ceramics\u27 melting point, AlN and salts transformed into alumina and glass phases respectively, and nucleation and crystal growth of glass ceramics at high temperature

Responses of Soil Organic Carbon Decomposition and Temperature Sensitivity to N and P Fertilization in Different Soil Aggregates in a Subtropical Forest

Soil organic carbon (SOC) decomposition, a key process controlling the carbon (C) loss from terrestrial soils to the atmosphere, varies with soil aggregate size and is influenced by increasing nitrogen (N) and phosphorus (P) inputs from anthropogenic activities. However, how increasing N and P affects SOC decomposition and its temperature sensitivity (Q10) in soil aggregates remains unclear. Thus, we collected soils from a subtropical Cunninghamia lanceolata forest receiving N and P addition for 8 years to explore the interactive effects of N and P fertilization on SOC decomposition and its Q10 in mega-aggregates (>2 mm, MeA), macroaggregates (0.25–2.0 mm, MaA), and microaggregates (Q10. Specifically, SOC decomposition in MiA is 49.2% and 26.0% higher than MeA and MaA, respectively. Moreover, the averaged Q10 values were 2.29, 2.26 and 1.83 in MeA, MaA and MiA. SOC decomposition significantly increased by 39.4% in MaA and 23.7% in MiA with N fertilization, but P fertilization had less impact. However, P fertilization increased Q10 by 46.7% in MeA and 46.6% in MaA. Furthermore, we found P fertilization changed the influences of N fertilization on SOC decomposition in MaA and MiA but had no effect on responses of Q10 to N fertilization. Overall, our findings suggested that there were differences in SOC decomposition and Q10 among aggregates, and fertilization treatment had an impact on them. Our results highlighted the significance of considering differences in SOC decomposition and its response to climate warming and nutrient input among different aggregates in the prediction of SOC dynamics and its feedback to environmental changes in terrestrial ecosystems under climate warming scenarios

Controlling the composition and magnetic properties of nano-SrFe_12 O_19 powder synthesized from oily cold mill sludge by the citrate precursor method

This paper proposes a new method for producing nano-SrFe 12 O 19 powder by the citrate precursor route using solid waste as a source of iron. This solid iron-containing waste, which exists in the form of an oily sludge, is produced by a cold rolling mill. This sludge was first subjected to a process, including sulfuric acid leaching, oxidation, precipitation, and nitric acid leaching, to obtain an iron nitrate (Fe(NO 3 ) 3 ) solution. Next, the Fe(NO 3 ) 3 solution was mixed with a strontium nitrate (Sr(NO 3 ) 2 ) solution obtained by subjecting strontium carbonate to nitric acid leaching. Subsequently, citric acid, as chelating agent, and ammonia water, as precipitating agent, were added to the mixed solution to form a gel. The gel was dried and spontaneously combusted, then annealed at different temperatures for 2 h in flowing air. The effects of the Fe 3+ /Sr 2+ molar ratio and annealing temperature on the formation, morphology, and magnetic properties of SrFe 12 O 19 were investigated. The results showed that single-phase SrFe 12 O 19 powder was obtained by decreasing the Fe 3+ /Sr 2+ molar ratio from the stoichiometric value of 12 to 11.6 and increasing the annealing temperature to 1000 \ub0C for 2 h. Adjustment of the Fe/Sr molar ratio to 12 and the annealing temperature to 900 \ub0C enabled the magnetic properties to be optimized, including saturation magnetization (Ms) 80.2 emu/g, remanence magnetization (Mr) 39.8 emu/g, and coercive force (Hc) 6318 Oe

Numerical analysis on the dynamic airtightness of a railway vehicle passing through tunnels

A high-speed train passes through a tunnel, the generated pressure wave largely impacts train body and will propagate into carriages through gaps, which brings passengers ear discomfort issues in the daily traffic. The dynamic airtightness of railway vehicle indicates the sealing performance of carriages that means how much the interior room will be influenced by the tunnel pressure wave acting on the train body surface. This paper presents an investigation on the dynamic airtightness of high-speed trains and the unsteady pressure changes that are transmitted from outside to inside compartment of the train. Unsteady compressible Reynolds-Averaged Navier-Stokes simulations were used to study the dynamic sealing performance of a railway vehicle as a function of factors such as amplitude and frequency of the exterior pressure variations, the equivalent leakage area, and the scaling ratio of the carriage model. It is found that the dynamic airtightness coefficient exhibits a close inversely proportional relationship with the leakage area; the leakage area plays a decisive role in the dynamic airtightness of the carriage. For a given leakage area, the mechanism of pressure transmission from the outside to the inside of the carriage is found not to change with variations in the amplitude and frequency of the exterior pressure. In the same time, the dynamic airtightness coefficient τdyn is found to have a direct and fixed inversely proportional relationship with the scale factor of the carriage model