Ecological assessment of the impact of agricultural activity on the emission of carbon dioxide from the leached chernozem of the Tobol-Ishim interfluve

The purpose of this work is to study carbon dioxide emissions from the surface of virgin and arable chernozem during the growing season of the Tobol-Ishim interfluve. Methods. The study was conducted on virgin land, in pure steam, under grain crops and corn from May to October. The intensity of carbon dioxide release was determined by the method of Shtatnov with titration in the field. Results. Based on previous studies, based on scientifically based approaches, as well as our own experimental data, the relationship between carbon dioxide emission and hydrothermal conditions of the humus layer (0–30 cm) was investigated, and the degree of influence of the type of land and crops on the release of CO2 from the surface of leached chernozem was determined. It has been established that the chernozems of Western Siberia are characterized by very low biological activity in the spring and autumn periods. CO2 emissions in May averaged 1.0–1.6 kg/ha per hour with a coefficient of variation of 8 %. The peak release of carbon dioxide into the atmosphere occurs in June-July (2.6–6.5 kg/ha per hour). It was revealed that under grain crops the gaseous losses of C–CO2 in the summer period amount to 4.1–6.5 kg/ha per hour, and in the area of pure steam – 2.3–3.4 kg/ha. The determining role in the intensity of carbon dioxide release is played by the soil temperature (r = 0.7). During the years of research, there were no dry periods, which did not allow us to establish a reliable effect of soil moisture on CO2 emissions, the correlation coefficient was 0.2 units. Based on the results obtained, a low degree (12.8 %) of the influence of the type of land (virgin land/arable land) and crops (cereals/corn) on the intensity of carbon dioxide release into the atmosphere from the surface of chernozem was revealed. The maximum degree of influence was in hydrothermal soil conditions (65 %), on which the activity of the soil microbiota and the root system of plants depended. Scientific novelty. For the first time, the intensity of carbon dioxide release from the surface of leached chernozem was studied for the Tobol-Ishim interfluve and the degree of influence of the anthropogenic factor against the background of the hydrothermal regime of soil was established.

Defining patterns in the influence exerted by the interelated biochemical corrosion on concrete building structures under the conditions of a chemical enterprise

The effect of microbial and chemical corrosion on concrete structures operated in the conditions of chemical enterprises has been established that makes it possible to reliably predict the timing of their decommissioning in order to prevent industrial disasters. Even though the construction complies with all building codes, concrete structures eventually undergo chemical and biological corrosion. The innovation proposed in this study implies investigating the depth and degree of damage to concrete at the microscopic level by the method of raster electron microscopy. In addition, the TPD-MS method has been suggested for determining the quantitative and qualitative state of the carbonate components of concrete and sulfur compounds. This study has found that in concrete samples from the titanium dioxide production plant, the amount of carbon dioxide release is twice less than in control samples at t=600 °C while the level of sulfur dioxide, on the contrary, increases. This is due to the ability of thionic bacteria to accumulate sulfate acid that destroys the cementing component in concrete. The reported results confirm the impact of products of the activity of Acidithiobacillus thiooxidans microorganisms on corrosion processes in concrete. In addition, when using the TPD-MS method, it was established in the storage room of the finished product that heating the control sample of concrete leads to a release of the significant amount of СО2 at t=580–600 °C. However, the experimental samples of concrete are almost lacking carbon compounds because the acid metabolites of microfungi interfere with its formation. Microscopic and REM studies revealed the localization of Acidithiobacillus thiooxidans and Aspergillus fumigatus in concrete. This study has established patterns related to the mechanism that forms chemical compounds in concrete and the metabolism of microorganisms

Effects of Two Types of Straw Biochar on the Mineralization of Soil Organic Carbon in Farmland

To investigate the effects of biochar on soil carbon composition and transformation, the effects of 1%, 2%, and 5% mass ratios of banana and cassava straw biochar on carbon dioxide release, total organic carbon (TOC), soluble organic carbon (SOC), and enzyme activity in soil were studied in incubation experiments at a constant temperature in the laboratory. The results showed that the cumulative CO2 emissions from cassava straw were 15.82 (1% addition ratio) and 28.14 μg·kg−1 (2%), which were lower than those from banana straw, i.e., 46.77 (1%) and 59.26 μg·kg−1 (2%). After culture, the total organic carbon contents of cassava straw were 8.55 (5%), 5.27 (2%), and 3.98 μg·kg−1 (1%), which were higher than those of banana straw, i.e., 6.31 (5%), 4.23 (2%), and 3.16 μg·kg−1 (1%). The organic carbon mineralization rate in each treatment showed a trend of increasing first, then decreasing, and finally stabilizing. There was a very significant positive correlation between catalase and urease activity in soil with cassava straw biochar and between catalase activity and SOC mineralization with banana straw biochar. It plays an important role in the transformation and decomposition of organic carbon. These results show that the application of biomass carbon can significantly improve the organic carbon content and enzyme activity of farmland soil, increase the cumulative mineralization amount and mineralization rate of SOC, and thus increase the carbon sequestration capacity of soil.

An analysis of the periodically forced PP04 climate model, using the theory of non-smooth dynamical systems

In this paper, we perform a careful analysis of the forced PP04 model for climate change, in particular the behaviour of the ice ages. This system models the transition from a glacial to an inter-glacial state through a sudden release of oceanic carbon dioxide into the atmosphere. This process can be cast in terms of a Filippov dynamical system, with a discontinuous change in its dynamics related to the carbon dioxide release. By using techniques from the theory of non-smooth dynamical systems, we give an analysis of this model in the cases of both no insolation forcing and also periodic insolation forcing. This reveals a rich, and novel, dynamical structure to the solutions of the PP04 model. In particular, we see synchronized periodic solutions with subtle regions of existence which depend on the amplitude and frequency of the forcing. The orbits can be created/destroyed in both smooth and discontinuity-induced bifurcations. We study both the orbits and the transitions between them and make comparisons with actual climate dynamics.

Abrupt CO2 release to the atmosphere under glacial and early interglacial climate conditions

Pulse-like carbon dioxide release to the atmosphere on centennial time scales has only been identified for the most recent glacial and deglacial periods and is thought to be absent during warmer climate conditions. Here, we present a high-resolution carbon dioxide record from 330,000 to 450,000 years before present, revealing pronounced carbon dioxide jumps (CDJ) under cold and warm climate conditions. CDJ come in two varieties that we attribute to invigoration or weakening of the Atlantic meridional overturning circulation (AMOC) and associated northward and southward shifts of the intertropical convergence zone, respectively. We find that CDJ are pervasive features of the carbon cycle that can occur during interglacial climate conditions if land ice masses are sufficiently extended to be able to disturb the AMOC by freshwater input.

Respiratory failure: Classification, Epidemiology and Etiology Review

Respiratory failure is a detailed syndrome of the respiratory system failing to perform the function of gas exchange, oxygen intake, and carbon dioxide release. Acute respiratory failure is the most common cause of organ failure in intensive care units (ICUs) with high mortality rates. The classification can be reviewed from two categories of acute respiratory failure and chronic respiratory failure. Acute respiratory failure is often found with the failure of other vital organs. Death is caused by multiple organ dysfunction syndrome (MODS). Etiology can be seen in two categories, namely Central nervous system Depression, Impaired ventilation, Impaired equilibrium perfusion ventilation (V/Q Mismatch), Trauma, Pleural effusion, hemothorax, and pneumothorax, Acute pulmonary disease. Respiratory failure, like failure in other organ systems, can be identified based on clinical features or laboratory tests.

Changes in radiative forcing due to clear-cutting in Sweden

<p>Land cover conversion affects climate by imposing perturbations in the surface properties and greenhouse gas fluxes. Forest management systems often disregard that modification in surface albedo influences the exchange of energy and greenhouse gases. In this study, we examine the net climatic effect of clear-cutting in high-latitude regions by comparing the importance of biogeophysical (albedo) and biogeochemical (carbon dioxide release) changes in Sweden. The hypothesis is that the albedo effect of high-latitude clear-cutting can reduce climate warming.</p><p>Data on incoming and reflected shortwave radiation was obtained from four-component net radiometers installed in the forest and neighbouring clear-cut sites, in southern (56°N), central (60°N) and northern (64°N) Sweden. The study site pairs along a latitudinal gradient were chosen to account for different climatic conditions. Data at these station pairs covered a continuous period of three (2016-2018), five (2014-2018) and one year (2014), respectively. Due to lack of clear-cut measurement stations in close vicinity to the northernmost forest site, the shortwave radiation data was retrieved from an open mire, where albedo and its temporal dynamics are similar to a clear-cut. All the forest stations and the mire station are part of ICOS Sweden network. Data on carbon dioxide release from clear-cutting was estimated as a difference in the aboveground carbon stock of the standing biomass between forest and clear-cut sites. The estimated carbon dioxide release was translated into an equivalent change in absorbed shortwave radiation and compared to the radiative forcing by albedo difference between forest and clear-cut sites.</p><p>Our results underline results from previous studies showing that the magnitude of the net radiative forcing by clear-cutting varies considerably depending on the latitudinal position of the examined sites. Based on available data, clear-cutting in southern and central Sweden had a warming effect on the climate while in northern Sweden clear-cutting had a net cooling effect. However, large inter-annual variability (central Sweden) and lack of available continuous data (northern Sweden) resulted in high uncertainty of the climatic effects of changes in net radiative forcing due to clear-cutting. Our study indicates that the albedo effect has an essential role in the estimation of the climatic effect of clear-cutting and should thus be incorporated in future forest management strategies.</p>