Microbial processes contributing to N₂O production in two sandy Scottish soils

The objective of the present work was to investigate the potential contribution of different microbial processes to N20 fluxes and the influence of the main environmental factors on these processes in two light textured Scottish soils. Two imperfectly drained brown forest soils of the Peffer Series, derived from fine beach sand, were studied. One was a sandy loam, sampled from a deciduous woodland and the other was a loamy sand, sampled from a nearby winter wheat field, at Gullane, East Lothian, Scotland. Both soils had slightly alkaline pEls.Field and laboratory studies demonstrated that more than one process was responsible for N20 emissions. Field results showed two different patterns of N20 emissions. Measurements with static manual chambers showed very low fluxes (1.4 - 1.5 g N20- N ha'1 d'1) throughout the year, though with some seasonal variation. These fluxes were not correlated with any environmental parameter measured. However, measurements with automatic chambers occasionally showed higher N20 fluxes (up to 44 g N20-N ha' 1 d'1). The latter were favoured by the presence of fresh organic matter and high concentrations of NH/-N (rather than N03'-N). This was shown to be true both in a fertilization experiment in the woodland and in an incubation experiment with woodland soil cores. The nature of the processes responsible for the N20 field emissions, e.g. denitrification, autotrophic and heterotrophic nitrification, are discussed and it is concluded that nitrification (either autotrophic or heterotrophic) was mainly responsible for the low N20 fluxes, whereas denitrification or heterotrophic nitrification-dénitrification was the main source of the higher fluxes.N20 emissions, determined in a laboratory experiment in which the soils were incubated with different sources of nitrogen, with or without glucose, and with 0, 1 and 100 ml C2H2 I'1, showed large differences in the rate of N20 production both between the two soils and between the different N treatments. The arable soil showed very low N20 emissions derived from reduced forms of N as compared with the N20 which was produced when the soil was provided with N02' or N03" and a C source, suggesting a very active denitrifier population. In contrast, the woodland soil showed a very low denitrification activity and a much higher N20 production derived from the oxidation of NH/ and reduction of N02' by some processes probably mediated by autotrophic or heterotrophic nitrifiers. In both soils, the highest N20 emissions were induced by N02' addition. Those emissions were demonstrated to have a biological origin, as no significant N20 emissions were measured when the soil was autoclaved.Experiments carried out using 15N pool dilution and enrichment techniques and physiological block techniques for prokaryotic and eukaryotic microorganisms (streptomycin and cycloheximide, respectively) showed that a well established population of heterotrophic nitrifiers was present in the woodland soil. The balance between autotrophic and heterotrophic nitrification in the soil was influenced by the concentration of organic N. The heterotrophic activity increased from 18% to 56% of the total nitrification activity when the peptone concentration was increased from 70 to 280 pg N g'1.Low concentrations (0-2.5 mg g'1) of both antibiotics had no apparent biocidal and disruptive effect on the microbial biomass, in the first 48 h incubation, indicating only a selective action of protein synthesis inhibition, whereas at high concentration (7.5 mg g'1) cycloheximide had a marked biocidal effect on the overall population of nitrifiers, blocking completely any nitrification activityHeterotrophic nitrification was completely blocked and autotrophic nitrification was reduced at 2 mg cycloheximide g'1, while streptomycin only slightly reduced both autotrophic and heterotrophic nitrification, even at 3.5 mg g'1. This suggested that fungi could have a dominant role in N03‘ production from readily available organic-N in the woodland soil, even at slightly alkaline pH. The partial inhibition of autotrophic nitrification by low concentrations of cycloheximide indicate the possibility for another fungal pathway of N03" production which might utilize an inorganic route. This possibility was also supported by the results with non-isotopic techniques, where the N20 fluxes induced by peptone addition were completely inhibited by low concentrations of cycloheximide (1 -2 mg cycloheximide g'1) but also by 0.1% ( 1 0 0 Pa) acetylene, suggesting a possible role of ammonia monooxygenase in an organic- inorganic pathway of nitrification in fungal metabolism

Assessing Soil Erosion Susceptibility for Past and Future Scenarios in Semiarid Mediterranean Agroecosystems

The evaluation of soil erosion rate, particularly in agricultural lands, is a crucial tool for long-term land management planning. This research utilized the soil and water assessment tool (SWAT) model to simulate soil erosion in a semiarid watershed located in South Portugal. To understand the evolution of the erosive phenomenon over time, soil erosion susceptibility maps for both historical and future periods were created. The historical period exhibited the highest average soil erosion for each land use, followed by the representative concentration pathways (RCPs) 8.5 and 4.5 scenarios. The differences in soil loss between these two RCPs were influenced by the slightly increasing trend of extreme events, particularly notable in RCP 8.5, leading to a higher maximum value of soil erosion. The research highlighted a tendency towards erosion in the agroforestry system known as “montado”, specifically on Leptosols throughout the entire basin. The study confirmed that Leptosols are most susceptible to sediment loss due to their inherent characteristics. Additionally, both “montado” and farmed systems were found to negatively impact soil erosion rates if appropriate antierosion measures are not adopted. This underscores the importance of identifying all factors responsible for land degradation in Mediterranean watersheds. In conclusion, the study highlighted the significance of assessing soil erosion rates in agricultural areas for effective land management planning in the long run. The utilization of the SWAT model and the creation of susceptibility maps provide valuable insights into the erosive phenomenon’s dynamics, urging the implementation of antierosion strategies to protect the soil and combat land degradation in the region.info:eu-repo/semantics/publishedVersio

CO2 and CH4 fluxes across a Nuphar lutea (L.) Sm. stand

Floating-leaved rhizophytes can significantly alter net carbon dioxide (CO 2) and methane (CH 4) exchanges with the atmosphere in freshwater shallow environments. In particular, CH 4 efflux can be enhanced by the aerenchyma-mediated mass flow, while CO 2 release from supersaturated waters can be reversed by the plant uptake. Additionally, the floating leaves bed can hamper light penetration and oxygen (O 2) diffusion from the atmosphere, thus altering the dissolved gas dynamics in the water column. In this study, net fluxes of CO 2 and CH 4 were measured seasonally across vegetated [Nuphar lutea (L.) Sm.] and free water surfaces in the Busatello wetland (Northern Italy). Concomitantly, dissolved gas concentrations were monitored in the water column and N. lutea leaf production was estimated by means of biomass harvesting. During the vegetative period (May-August), the yellow waterlily stand resulted a net sink for atmospheric carbon (from 97.5 to 110.6 g C-CO 2 m -2), while the free water surface was a net carbon source (166.3 g C-CO 2 m -2). Both vegetated and plant-free areas acted as CH 4 sources, with an overall carbon release comprised between 71.6 and 113.3 g C-CH 4 m -2. On the whole, water column chemistry was not affected by the presence of the floating leaves; moreover, no significant differences in CH4 efflux were evidenced between the vegetated and plant-free areas. In general, this study indicates that the colonization of shallow aquatic ecosystems by N. lutea might not have the same drastic effect reported for free-floating macrophytes

New tree monitoring systems: from Industry 4.0 to Nature 4.0

Recently, Internet of Things (IoT) technologies have grown rapidly and represent now a unique opportunity to improve our environmental monitoring capabilities at extremely low costs. IoT is a new system of thinking in which objects, animals or people are equipped with unique identifiers and transfer data a network without requiring human-to-human or human-to-computer interaction. IoT has evolved from the convergence of wireless technologies, microelectromechanical systems (MEMS) and the Internet. The development of these technologies in environmental monitoring domains allows real-time data transmission and numerous low-cost monitoring points. We have designed a new device, the TreeTalker©, which is capable of measuring water transport in trees, diametrical growth, spectral characteristics of the leaves and microclimatic parameters and transmit data in semi-real time. Here we introduce the device’s features, provide an example of monitored data from a field test site and discuss the application of this new technology to tree monitoring in various contexts, from forest to urban green infrastructures management and ecological research

Assessment of full carbon budget of Italy: the CarbIUS project

Regional carbon balances, funded, for the Italian side, by the Italian Ministry of Environment in the context of a bilateral agreement to develop scientific collaborations in Global Change Research between Italy and USA signed in 2001. The two regions selected are Italy and Oregon-California; there are many similarities between these two regions (climate, vegetation, topography, population pressure, etc.) but, on other hand, there are also interesting contrasts in societal aspects like demography, land-use history and emissions. The main CarbIUS objectives are 1) the identification of spatial and temporal variability of carbon sources and sinks and the relative contribution of the different anthropogenic and biogenic components, 2) the impact of land use changes and human population dynamics on the carbon balance, 3) the quantification of the effects of climate and natural disturbances on the terrestrial carbon stocks and fluxes and 4) the application of new methodologies to investigate carbon metabolism at the plot, ecosystem and regional scale. In this paper will be presented the methodologies that we are using to assess the contribution of the different components to the full carbon budget, like carbon stocks and fluxes, disturbances (harvesting, wild forest fires and forest pathology), CH4 and NO2 fluxes and anthropogenic emissions. All these information will be input in a Data Assimilation System and the results will be validated using sub-regional airborne measurements of carbon fluxes

Soil Quality Characterization of Mediterranean Areas under Desertification Risk for the Implementation of Management Schemes Aimed at Land Degradation Neutrality

Soil is a key component of ecosystems as it provides fundamental ecosystem functions and services, first of all supporting primary productivity, by physical, chemical and biological interaction with plants. However, soil loss and degradation are at present two of the most critical environmental issues. This phenomenon is particularly critical in Mediterranean areas, where inappropriate land management, in combination with the increasingly harshening of climatic conditions due to Climate Change, is leading to significant land degradation and desertification and is expected to worsen in the future, leading to economic and social crisis. In such areas, it is of fundamental importance to apply sustainable management practices, as conservation/restoration measures, to achieve Land Degradation Neutrality. This approach is at the core of the LIFE project Desert-Adapt “Preparing desertification areas for increased climate change” which is testing a new framework of sustainable land management strategies based on the key concept that the maintenance of ecosystems quality is necessarily connected to economic and social security in these fragile areas. The project will test adaptation strategies and measures in 10 sites of three Mediterranean areas under strong desertification risk, Alentejo in Portugal, Extremadura in Spain and Sicily in Italy. We present the baseline data of soil quality analysis from 32 sites in the 10 study areas of the project. Key drivers of soil quality and quantity were identified and used as basis to select sustainable management strategies focused on the maintenance, improvement and/or recovery of soil-based ecosystem services, with particular attention to climate change adaptation and land productivity. The final objective of the project is to demonstrate, according to the LDN approach, the best adaptation strategies to recover degraded areas from low-productive systems into resource-efficient and low-carbon economies to preserve ecosystem quality and booster economy and social securit

Long tree-ring chronologies provide evidence of recent tree growth decrease in a central african tropical forest

It is still unclear whether the exponential rise of atmospheric CO2 concentration has produced a fertilization effect on tropical forests, thus incrementing their growth rate, in the last two centuries. As many factors affect tree growth patterns, short -term studies might be influenced by the confounding effect of several interacting environmental variables on plant growth. Long-term analyses of tree growth can elucidate long-term trends of plant growth response to dominant drivers. The study of annual rings, applied to long tree-ring chronologies in tropical forest trees enables such analysis. Long-term tree-ring chronologies of three widespread African species were measured in Central Africa to analyze the growth of trees over the last two centuries. Growth trends were correlated to changes in global atmospheric CO2 concentration and local variations in the main climatic drivers, temperature and rainfall. Our results provided no evidence for a fertilization effect of CO2 on tree growth. On the contrary, an overall growth decline was observed for all three species in the last century, which appears to be significantly correlated to the increase in local temperature. These findings provide additional support to the global observations of a slowing down of C sequestration in the trunks of forest trees in recent decades. Data indicate that the CO2 increase alone has not been sufficient to obtain a tree growth increase in tropical trees. The effect of other changing environmental factors, like temperature, may have overridden the fertilization effect of CO2.It is still unclear whether the exponential rise of atmospheric CO2 concentration has produced a fertilization effect on tropical forests, thus incrementing their growth rate, in the last two centuries. As many factors affect tree growth patterns, short -term studies might be influenced by the confounding effect of several interacting environmental variables on plant growth. Long-term analyses of tree growth can elucidate long-term trends of plant growth response to dominant drivers. The study of annual rings, applied to long tree-ring chronologies in tropical forest trees enables such analysis. Long-term tree-ring chronologies of three widespread African species were measured in Central Africa to analyze the growth of trees over the last two centuries. Growth trends were correlated to changes in global atmospheric CO2 concentration and local variations in the main climatic drivers, temperature and rainfall. Our results provided no evidence for a fertilization effect of CO2 on tree growth. On the contrary, an overall growth decline was observed for all three species in the last century, which appears to be significantly correlated to the increase in local temperature. These findings provide additional support to the global observations of a slowing down of C sequestration in the trunks of forest trees in recent decades. Data indicate that the CO2 increase alone has not been sufficient to obtain a tree growth increase in tropical trees. The effect of other changing environmental factors, like temperature, may have overridden the fertilization effect of CO2

Resilience and response of the congenital cardiac network in Italy during the COVID-19 pandemic

: The worldwide response to the current COVID-19 pandemic has been focused on how to prevent the disease and to protect the high-risk patient from a potentially lethal infection. Several consensus and guidelines articles have been published dealing with the cardiac patient with systemic hypertension, heart transplant or heart failure. Very little is known about the patients, both in the pediatric as well as in the adult age, with congenital heart disease. The peculiar physiology of the heart with a native, repaired or palliated congenital heart defect deserves a specialized care. Hereby we describe the early recommendations issued by the Italian Society of Pediatric Cardiology and Congenital Heart Disease and how the network of the congenital cardiac institutions in Italy reacted to the threat of potential wide spread of the infection among this fragile kind of patient

Critical range of soil organic carbon in southern Europe lands under desertification risk

Soil quality is fundamental for ecosystem long term functionality, productivity and resilience to current climatic changes. Despite its importance, soil is lost and degraded at dramatic rates worldwide. In Europe, the Mediterranean areas are a hotspot for soil erosion and land degradation due to a combination of climatic conditions, soils, geomorphology and anthropic pressure. Soil organic carbon (SOC) is considered a key indicator of soil quality as it relates to other fundamental soil functions supporting crucial ecosystem services. In the present study, the functional relationships among SOC and other important soil properties were investigated in the topsoil of 38 sites under different land cover and management, distributed over three Mediterranean regions under strong desertification risk, with the final aim to define critical SOC ranges for fast loss of important soil functionalities. The study sites belonged to private and public landowners seeking to adopt sustainable land management practices to support ecosystem sustainability and productivity of their land. Data showed a very clear relationship between SOC concentrations and the other analyzed soil properties: total nitrogen, bulk density, cation exchange capacity, available water capacity, microbial biomass, C fractions associated to particulate organic matter and to the mineral soil component and indirectly with net N mineralization. Below 20 g SOC kg−1, additional changes of SOC concentrations resulted in a steep variation of all the analyzed soil indicators, an order of magnitude higher than the changes occurring between 50 and 100 g SOC kg−1 and 3–4 times the changes observed at 20–50 g SOC kg−1. About half of the study sites showed average SOC concentration of the topsoil centimetres <20 g SOC kg−1. For these areas the level of SOC might hence be considered critical and immediate and effective recovery management plans are needed to avoid complete land degradation in the next future.info:eu-repo/semantics/publishedVersio

The Italian TREETALKER NETWORK (ITT-Net): continuous large scale monitoring of tree functional traits and vulnerabilities to climate change

20openItalian coauthor/editorThe Italian TREETALKER NETWORK (ITT-Net) aims to respond to one of the grand societal challenges: the impact of climate changes on forests ecosystem services and forest dieback. The comprehension of the link between these phenomena requires to complement the most classical approaches with a new monitoring paradigm based on large scale, single tree, high frequency and long-term monitoring tree physiology, which, at present, is limited by the still elevated costs of multi-sensor devices, their energy demand and maintenance not always suitable for monitoring in remote areas. The ITT-Net network will be a unique and unprecedented worldwide example of real time, large scale, high frequency and long-term monitoring of tree physiological parameters. By spring 2020, as part of a national funded project (PRIN) the network will have set 37 sites from the north-east Alps to Sicily where a new low cost, multisensor technology “the TreeTalker®” equipped to measure tree radial growth, sap flow, transmitted light spectral components related to foliage dieback and physiology and plant stability (developed by Nature 4.0), will monitor over 600 individual trees. A radio LoRa protocol for data transmission and access to cloud services will allow to transmit in real time high frequency data on the WEB cloud with a unique IoT identifier to a common database where big data analysis will be performed to explore the causal dependency of climate events and environmental disturbances with tree functionality and resilience. With this new network, we aim to create a new knowledge, introducing a massive data observation and analysis, about the frequency, intensity and dynamical patterns of climate anomalies perturbation on plant physiological response dynamics in order to: 1) characterize the space of “normal or safe tree operation mode” during average climatic conditions; 2) identify the non-linear tree responses beyond the safe operation mode, induced by extreme events, and the tipping points; 3) test the possibility to use a high frequency continuous monitoring system to identify early warning signals of tree stress which might allow to follow tree dynamics under climate change in real time at a resolution and accuracy that cannot always be provided through forest inventories or remote sensing technologies.openCastaldi, S.; Antonucci, S.; Asgharina, S.; Battipaglia, G.; Belelli Marchesini, L.; Cavagna, M.; Chini, I.; Cocozza, C.; Gianelle, D.; La Mantia, T.; Motisi, A.; Niccoli, F.; Pacheco Solana, A.; Sala, G.; Santopuoli, G.; Tonon, G.; Tognetti, R.; Zampedri, R.; Zorzi, I.; Valentini, R.Castaldi, S.; Antonucci, S.; Asgharina, S.; Battipaglia, G.; Belelli Marchesini, L.; Cavagna, M.; Chini, I.; Cocozza, C.; Gianelle, D.; La Mantia, T.; Motisi, A.; Niccoli, F.; Pacheco Solana, A.; Sala, G.; Santopuoli, G.; Tonon, G.; Tognetti, R.; Zampedri, R.; Zorzi, I.; Valentini, R