Organic Matter Decomposition Processes Research Articles

Makrofauna Tanah di Bawah Pohon Jelutung Rawa (Dyera polyphylla Miq) Di Kebun Benih Semai (KBS) Universitas Palangka Raya

Decomposition of organic matter in the soil is closely related to the presence of soil macrofauna. The better the process of organic matter decomposition, the better the physical and chemical properties of the soil, which, of course, will support soil fertility in a land area. This research aims to determine the presence of soil macrofauna under Jelutung Rawa trees (Dyera polyphylla Miq) in the peatland of the Seedling Garden (KBS) at Palangka Raya University. The research method was conducted by sampling soil macrofauna through Hand sorting method at 25 observation points and Pittfall Trap method at 20 observation points. The observed and identified soil macrofauna were examined in the laboratory using identification guidelines and literature on macrofauna types. The data were analyzed using the Shannon-Wiener species diversity index formula, the Margalef species richness index, the Pielou evenness index, and the calculation of species presence frequency. The research findings revealed 24 species, 23 genera, 20 families, 7 classes, and 3 phyla of soil macrofauna, with a total of 3,579 individuals. The values of the species diversity index (H'), species richness index (Dmg), evenness index (E), and the frequency of soil macrofauna presence (F) at KBS, Palangka Raya University were as follows: H' = 2.303325269 (moderate category), Dmg = 2.810760521 (moderate category), E = 0.724759677 (fairly even category), and frequency of presence, F = 80% - 100%.

Organic Matter Decomposition: A View on The Fate of Lignocellulosic Materials

Organic matter decomposition, a complex process with all the physico-chemical and biological factors leads to breakdown of organic residues. The prime role in this process is played by microorganisms with their enzymes. The process is beneficial not only to generate matters of soil fertility enhancement, but also it can lead to the products that can add value to soil. Slow and difficult matters to be decomposed like lingo-cellulosic materials can also be subjected to this decomposition process for the generation of not only new and beneficial microflora, but also products of value. The present work discusses here in brief the process of organic matter decomposition and its importance in rice straw breakdown and lignocellulosic material decomposition.

STRUKTUR KOMUNITAS DIPLOPODA TANAH PADA KETINGGIAN BERBEDA DI PERKEBUNAN TEH KABAWETAN BENGKULU

Soil diplopods are an important biotic component in agricultural land ecosystems. Its presence in the soil is an important in the decomposition process of soil organic matter, and plays a role in increasing soil fertility. This study aims to study the community structure of soil Diplopoda at different altitudes in the Bengkulu Kabawetan Tea Plantation. The location of the study used the stratified sampling method which is based on the altitude of 800 m, 900 m and 1000 m above sea level. Soil Diplopods were collected by using the 50x50 cm quadratic method and a 100 m line transect. Data analysis consisted of density, relative density, diversity index, and Morisita index. There were 4 types of soil Diplopods in the Bengkulu Kabawetan Tea Plantation, namely Arthrosphaera sp., Gyrodrepanum sp., Oxidus sp., and Trigoniulus sp. At an altitude of 900 m and 1000 m, 4 species of Diplopoda were found and at an altitude of 800 m consisted of 3 types of Diplopoda. The density of soil diplopods at the three study locations varied, with the highest density at an altitude of 1000 m followed by at an altitude of 800 m and at 900m. The diversity index at the three locations is low and moderate. The distribution of diplopods at the study site was random and uniform.

Impact of environmental factors on diversity of fungi in sediments from the Shenzhen River Estuary

In this study, to explore the relationship between environmental factors and fungal diversity in the Shenzhen River ecosystem, multiple methods including chemical analysis, culture isolation, qPCR analysis of fungal ITS region and ITS-based Illumina next-generation-sequencing were integrated. A total of 115 isolates were finally isolated and could be classified into 23 genera. Top three abundant genera isolated were Meyerozyma (18 strains), Aspergillus (17 strains) and Penicillium (14 strains). Based on the Illumina sequencing approach, 829 OTUs were affiliated to seven phyla, 17 known classes, and 162 genera, indicating the Shenzhen estuary sediments are rich in fungal diversity. The major fungal genera were Meyerozyma, Trichoderma and Talaromyces. Environmental factors showed a gradient change in Shenzhen estuary, and fungal abundance was only significantly correlated with NH4+. Shannon index was significantly correlated with pH and IC (P < 0.05). Principal coordinate analysis based on OTU level grouped into three clusters among sampling sites along with the IC and pH gradient. Functional guilds analysis suggests most of the fungi in this studying area were almost all saprotrophs, suggesting a large number of saprophytic fungi may play a significant role in the organic matter decomposition and nutrient cycling process. In summary, this study will deepen our understanding of fungi community in Shenzhen River ecosystem and their distribution and potential function shaped by environmental factors.

Effects of bio-oil - diesel blends: the performance and emissions of diesel engines with intake manifold variations

Alternative fuels such as vegetable oil, biodiesel, and bio-oil are potential alternatives for diesel engines. Bio-oil is one of the products of the decomposition process of chemical and organic matter by adding heating process without oxygen is called rapid pyrolysis. Bio-oil in the pyrolysis process is made from Brem waste. Brem is a typical food from the district of Madiun, Indonesia. This research is important because the switch from petroleum-sourced fuel to Bio-Oil oil cannot be automatically applied to diesel engines. Spray quality and combustion process, type and quality of fuel, and engine design and condition are some of the important parameters affecting diesel engine performance. Research data is very important because it can determine the intake manifold and the best bio-oil-diesel blends to be used in the operation of diesel engines with bio-oil-diesel blends. The research uses three variations of the intake manifold form. Variations of research with lamp loading of 650, 1300, 1950 and 2600 watts determine specific power and fuel consumption. Use an opacity smoke meter to determine the opacity of diesel engine exhaust gases. The fuel used is pure diesel fuel and Bio-Oil fuel B10, B15, and B20 resulting from the pyrolysis of Brem waste with a fuel volume of 25 ml for each research variable. The results of testing the intake manifold variation and the bio-oil-diesel blended are the intake manifold variation 1 with a fuel mixture variation of 20 % Bio-Oil - 80% pure diesel (B20), which has the best results both electric power, specific fuel consumption and opacity.

Divergent temporal variations in soil microbial attributes under a subtropic afforestation

Soil microorganisms fundamentally regulate biochemical processes of soil organic matter decomposition in terrestrial ecosystems. In this study, we examined seasonal and yearly variations in soil microbial attributes (i.e., total phospholipid fatty acids (PLFAs), bacteria (B) and fungi (F), actinobacteria (ACT), microbial respiration (MR)) and potential controls at two soil depths under conversion from the cropland and uncultivated land to afforested lands (woodland and shrubland) of different years (2015, 2017) in the Danjiangkou Reservoir of subtropical China. The total PLFA (2.29–11.24 ug g−1), B (1.66–6.73 ug g−1) and F (0.32–1.44 ug g−1) biomass did not significantly vary with seasons of 2015, but they were significantly higher in summer (3.73–13.97, 1.49–7.36, 0.47–2.31 ug g−1, respectively) than in winter (1.30–9.73, 0.61–5.79, 0.23–1.49 ug g−1, respectively) of 2017 due to the larger fluctuation in soil moisture between winter and summer of 2017. In contrast, the lower MR (0.58–2.56 mg CO2−1 g soil−1h) in summer compared to winter (0.77–3.77 mg CO2−1 g soil−1h) was observed in 2015 primarily due to higher soil moisture in winter, but the higher MR (0.77–4.42 mg CO2−1 g soil−1h) was detected in summer than that in winter (0.43–2.89 mg CO2−1 g soil−1h) of 2017, which was closely related to lower soil moisture together with larger PLFA biomass in summer. The MR significantly changed with seasons in afforested lands, but it did not significantly vary with seasons in cropland and uncultivated land. Conversely, the MR/total PLFAs ratios significantly changed with seasons in cropland and uncultivated land, but it did not significantly vary with seasons in afforested lands. Collectively, our results revealed the different temporal pattern of soil microbial community composition under afforestation, thereby providing very useful information for governments to better manage and protect agricultural land use in future global change scenarios.

The Analysis Of Peat Soil Biological Characteristics After Being Incubated Using Vermicompost From A Mixture Of Chicken Dung, Banana Hump, And Tofu Waste

Peatlands are formed from piles of trapped plant residues, obstructing their decomposition process. The organic matter decomposition process certainly involves soil microbes. This study aims to determine the biological characteristics of peat soil after incubation with vermicompost. This research was conducted at Kampung Perlabian Village, Kampung Rakyat Sub-district, South Labuhanbatu Regency, North Sumatra. Soil biological analysis was conducted in the soil biology laboratory, Faculty of Agriculture, University of North Sumatra. This study used a non-factorial Randomized Block Design (RAK) with three treatments: P0 (control), P1 (1 kg peat soil + 500-gram vermicompost), and P2 (1 kg peat soil + 1 kg vermicompost). The results showed that adding vermicompost fertilizer to peat soil with treatment two could increase the total bacteria by 6.17 x 106 cfu/ml and the total fungus by 8.8 x 105cfu/ml, and CO2 respiration by 4.125 (mg CO/day). As a result, the soil's microorganism's activity is a process in which microorganisms live and do activities in a soil mass.

Ecological networks of dissolved organic matter and microorganisms under global change

Microbes regulate the composition and turnover of organic matter. Here we developed a framework called Energy-Diversity-Trait integrative Analysis to quantify how dissolved organic matter and microbes interact along global change drivers of temperature and nutrient enrichment. Negative and positive interactions suggest decomposition and production processes of organic matter, respectively. We applied this framework to manipulative field experiments on mountainsides in subarctic and subtropical climates. In both climates, negative interactions of bipartite networks were more specialized than positive interactions, showing fewer interactions between chemical molecules and bacterial taxa. Nutrient enrichment promoted specialization of positive interactions, but decreased specialization of negative interactions, indicating that organic matter was more vulnerable to decomposition by a greater range of bacteria, particularly at warmer temperatures in the subtropical climate. These two global change drivers influenced specialization of negative interactions most strongly via molecular traits, while molecular traits and bacterial diversity similarly affected specialization of positive interactions.

Brightness Values-Based Discriminant Functions for Classification of Degrees of Organic Matter Decomposition in Soil Thin Sections

The decomposition of organic matter represents a fundamental pedogenetic process, since it impacts the carbon cycle and the release of nutrients to the soil. However, quantitative research aimed at micro-scale in situ analysis is scarce, despite its relevance in the decomposition process. Therefore, the objectives of this research were to generate discriminating functions of the degrees of organic matter decomposition, based on the brightness values associated with each morphological stage, and from this step, to generate thematic maps. Soil thin sections of forest and compost soils were selected, and petrographic microscope images with three light sources were taken: plane polarized light (PPL), crossed-polarized light (XPL), and crossed polarizers and a retardation plate (gypsum compensator) inserted (XPLλ). Subsequently, the RGB (red, green, blue) image was broken down into three bands, resulting in nine bands for each image. Two thousand sampling points were generated for each band, obtaining brightness values for each decomposed organic matter stage. The points were classified into four categories based on their degree of decomposition: no (A), light (B), moderate (C), and strong (D), in addition to porosity (P). Linear discriminant analysis was performed to obtain classification models for each level of decomposition. The results show that each degree of organic matter decomposition can be highlighted through specific light sources and a set of bands, with an overall accuracy of &amp;gt;94% and kappa coefficients of &amp;gt;0.75 for all classes. In addition, the resulting functions were validated in training images and high-resolution mosaics to create final thematic maps. The use of linear models automated the production and quality of thematic maps at the microscopic level, which can be useful in monitoring the organic matter decomposition process.

Lignocellulosics in plant cell wall and their potential biological degradation.

Lignocellulosic materials are composed of three main structural polymers: hemicellulose, cellulose, and lignin. Cellulose is a long chain molecule of glucose requiring a small number of enzymes for degradation due to its simple structure while lignin is a complex polymer of phenylpropane making its biochemical decomposition difficult. Under anaerobic conditions, lignocellulose breakdown is much easier and more rapid than aerobic conditions. Various studies have been carried out to estimate the rate of degradation of lignocellulosic materials. Microorganisms play a key role in the degradation of lignocellulosic materials because they produce a variety of hydrolytic enzymes including cellulase, proteases, xylanases, lipases, laccase, and phosphatases during the degradation of lignocellulosic materials. Based on the body of literature, microorganismal activity can provide useful information about the process of organic matter decomposition.

IMPLEMENTATION OF MASS COMPOSTING OF URBAN ORGANIC WASTE IN URBAN FARMING (KALIRUNGKUT VILLAGE, RUNGKUT DISTRICT, SURABAYA CITY)

Garbage is a very large natural resource originating from housing and markets which ultimately waste becomes an important problem for densely populated urban areas if not utilized properly. Composting is basically an effort to activate microbial activities in order to accelerate the decomposition process of organic matter. The result of the reshuffle is called compost which is used as fertilizer that can provide nutrients for plants and improve soil fertility.)This activity is the implementation of appropriate technology in the mass composting of urban organic waste, especially in the empowerment of urban agricultural land (urban faming) which is carried out in the RW area. 02 Kalirungkut Village, Rungkut District, Surabaya City.The models offered to solve the problem of urban organic waste for partners are: 1). Help prepare assistance to improve expertise and skills in the management of urban organic waste mass composting; 2). Provide support in mobilizing community participation so that they consciously and voluntarily understand waste problems in order to become compost products that are beneficial for the cultivation of productive plants and greening the surrounding environment; The results of the implementation of this appropriate technology show that there is awareness of community participation in waste management by implementing the 3R (reduce, refuse, recycle) aimed at reducing the amount of waste starting at the source by sorting household waste in the form of organic waste and inorganic waste. With the urban agriculture movement, it can be an alternative to maintain family food security, besides being able to make a major contribution in providing green open space

Water Limitation in Forest Soils Regulates the Increase in Weathering Rates under Climate Change

Climate change is generally expected to have a positive effect on weathering rates, due to the strong temperature dependence of the weathering process. Important feedback mechanisms such as changes in soil moisture, tree growth and organic matter decomposition can affect the response of weathering rates to climate change. In this study, the dynamic forest ecosystem model ForSAFE, with mechanistic descriptions of tree growth, organic matter decomposition, weathering, hydrology and ion exchange processes, is used to investigate the effects of future climate scenarios on base cation weathering rates. In total, 544 productive coniferous forest sites from the Swedish National Forest Inventory are modelled, and differences in weathering responses to changes in climate from two Global Climate Models are investigated. The study shows that weathering rates at the simulated sites are likely to increase, but not to the extent predicted by a direct response to elevated air temperatures. Besides the result that increases in soil temperatures are less evident than those in air temperature, the study shows that soil moisture availability has a strong potential to limit the expected response to increased temperature. While changes in annual precipitation may not indicate further risk for more severe water deficits, seasonal differences show a clear difference between winters and summers. Taking into account the seasonal variation, the study shows that reduced soil water availability in the summer seasons will strongly limit the expected gain in weathering associated with higher temperatures.

Exploring Dissolved Organic Carbon Variations in a High Elevation Tropical Peatland Ecosystem: Cerro de la Muerte, Costa Rica

Tropical peatlands are distributed mainly in coastal lowlands; however high elevation regions exhibit a large prevalence of small and fragmented peatlands that are mostly understudied. Artificial drainage of peatlands to expand the area of cattle farming, horticulture, and urbanization is increasing carbon losses to the atmosphere and streams worldwide. Here, we present an exploratory characterization of dissolved carbon optical properties in ombrotrophic peat bogs of the Talamanca range of Costa Rica, across an altitudinal gradient (2,400–3,100 m a.s.l.) during the rainy season. Dissolved organic matter (DOM) sources and decomposition processes were evaluated in the light of dissolved organic and inorganic carbon (DOC and DIC), optical properties, and major water chemistry. DOC concentrations ranged from 0.2 up to 47.0 mg/L. DIC concentrations were below 2 mg/L and δ13CDIC values indicated a mixture between soil organic matter, CO2 in soil water, and to a lesser degree DIC derived from bacterial CO2. Absolute fluorescence intensity of humic-like peaks was 6–7 times greater than fresh-like peaks across all sites. Fluorescence peak ratios coupled with the biological and humification indexes point to a greater relative contribution of recalcitrant soil-derived DOM. Excitation/Emission matrices denoted a high prevalence of humic and fulvic acids in the peat bogs, with moderate intensities in soluble microbial by-products-like and aromatic protein regions at three sites. Our data provides a baseline to underpin tropical carbon dynamics across high elevation peatlands.

A Warm Tea: The Role of Temperature and Hydroperiod on Litter Decomposition in Temporary Wetlands

Increasing global temperature and changes in the precipitation regime affect the global carbon cycle by altering the process of organic matter decomposition. Temporary aquatic systems are especially susceptible to climate change. We hypothesized that water availability and temperature affect the early and late stages of decomposition of litter differently and determine the decomposition rates according to litter type. We conducted two decomposition experiments using green (Camellia sinensis L.) and mint (Mentha piperita L.) tea in commercial bags. In the laboratory experiment, we incubated the bags at two contrasting temperatures (4 and 15°C) and in three simulated hydroperiods (M: moist, MS: submerged after 14 days, S: submerged). A field experiment was carried out in winter and spring in nine temporary wetlands (meadows) along a precipitation gradient (from forest to steppe ecosystems) in the Argentinean Patagonia. Water stimulated the leaching of soluble substances in the S treatment and was the conducting factor in early decomposition stages. Temperature stimulated tea decomposition in advanced stages, and both water and temperature exerted a different response depending on the litter type. In the field experiment, mass loss in meadows was determined by the hydroperiod condition, both in winter and spring. Detritus type was the controlling factor in steppe meadows, but on forest meadows water level stimulated both litter types, and temperature increased decomposition. Under the expected increase of temperature and decrease of precipitations in future climate scenarios, organic matter accumulation would increase in steppe meadows and decomposition would be higher in forest meadows.

Organic carbon composition and microbial transformation of seagrass meadow and its responses to eutrophication

<p indent="0mm">Carbon neutrality is an important concept in global climate change governance. Seagrass beds rank among the most productive autotrophic ecosystems on the planet, and are receiving increasing attention as globally-significant hotspots of organic carbon (“blue carbon”) sequestration. The blue carbon stored in seagrass beds has important implications for climate change mitigation. The protection of seagrass beds will also protect their organic carbon sequestration potential, consequently helping to achieve the goal of carbon neutrality. Unfortunately, about 29% of the world’s seagrass beds have been destroyed, with a loss rate of 7% a⁻¹ since 1990, mostly due to eutrophication. The organic carbon sequestration potential of seagrass beds could be influenced by the subsequent changes in organic carbon composition, and microbial transformation processes. We systematically reviewed the relevant local and international research to summarize the composition and microbial transformation of organic carbon and its responses to eutrophication. Organic carbon is present in various forms in seagrass beds, and can be roughly divided into primary producer living biomass carbon, litter organic carbon, water organic carbon, and sediment organic carbon according to its storage area. Organic carbon can also be divided into labile organic carbon (LOC), which is susceptible to microbial decomposition, and recalcitrant organic carbon (ROC), which is resistant to microbial decomposition. The total ROC (cellulose and lignin) content in seagrass is present in the range of <sc>153−561 mg/g,</sc> and accounts for more than 28.7% of the organic carbon in the seagrass plants. The ROC content of seagrass plants is affected by the species, morphology, tissue and organ types, and climatic zones. In the water column, color dissolved organic matter (CDOM) and neutral sugars are indicators of LOC, while the lignin phenol and humic-like fractions of fluorescent dissolved organic matter (FDOM) are potential tracers of ROC. The DOM in water can be divided into dissolved organic carbon (DOC), dissolved organic nitrogen (DON), and dissolved organic phosphorus (DOP). The DOC/DON and DOC/DOP ratios are used to reflect DOC lability and microbial bioavailability, with high DON and DOP concentrations indicating high DOC lability. In sediments, extractable organic carbon and microbial biomass carbon are important indicators of LOC, while aromatic hydrocarbons and alkanes are indicative of recalcitrant components. There are significant differences in the sediment organic carbon contents of temperate and tropical regions. Microorganisms play a vital role in the transformation of organic carbon. There are geographic differences in microbial composition, which are mainly influenced by the available habitats and climate zones, but there are no differences between seagrass species within a fine-scale seagrass bed. Different microorganisms have different decomposition capacities. <italic>R</italic>-strategist microbes, including Clostridiales<italic> </italic>and<italic> </italic>Gammaproteobacteria, are able to rapidly decompose LOC, while <italic>k</italic>-strategists, such as Verrucomicrobiae<italic> </italic>and Anaerolinae, can break down the more recalcitrant compounds. There is a succession of <italic>r</italic>- to <italic>k</italic>-strategists microbes during the decomposition of fresh organic matter (including fresh seagrass litter, DOC, and SOC). Eutrophication may lead to the transformation of the community structure of primary producers in seagrass beds from seagrass to macroalgae, which will increase the input of labile carbon. This consequently causes an increase in LOC in the plant biomass, water column, and sediments, but a decrease in ROC. The nutrient loading can affect the microbial community structure and enzyme activity, which will affect the microbial transformation of organic carbon. Furthermore, nutrient and LOC inputs may induce a “priming effect” that promotes the remineralization of stored organic carbon. Several future research directions for determining the transformation of seagrass beds and their organic carbon were proposed. (1) Extensive studies of the organic carbon components (LOC and ROC) in seagrass beds are required. (2) There is a need to better understand the composition, function, and gene expression of microbial communities in seagrass beds. (3) The eutrophication mechanisms in microbial communities and the related extracellular enzyme activities need to be determined. (4) The response of the organic matter decomposition process to nutrient loading and the interaction of nutrients and algae need to be studied. There is also a need to strengthen local research on the carbon storage potential of seagrass beds to mitigate global climate change and provide theoretical support for achieving carbon neutrality.

Drainage increases species richness and density of soil macro-invertebrates in the Zoige peatland of eastern Tibetan Plateau

Soil macro-invertebrates play an important role in the decomposition process of soil organic matter. As the world’s largest alpine peatland, the Zoige peatland on the eastern Tibetan Plateau is experiencing the decline in water table level primarily because of historic drainage. However, little is known about the responses of soil macro-invertebrate communities to water table decline. To address this issue, we established a field drainage experimental platform in 2013, which consists of low (50 cm deep drainage ditch) and intermediate (20 cm deep drainage ditch) water table level treatments, and the ambient (no drainage ditch) plots. In July (warm season) and November (cold season) of 2019, we examined the species composition, richness, densities and the vertical distribution of soil macro-invertebrates. Results showed that the species composition differed significantly among treatments. Species richness and densities of overall and different trophic groups (i.e., detritivores, herbivores and predators) of soil macro-invertebrates were significantly higher in the drained treatments compared to the ambient plots. Moreover, soil macro-invertebrates moved down to deeper soil layers in the low water table treatments compared to the ambient plots. In addition, sampling season (warm vs. cold) did not affect the responses of soil macro-invertebrates to water table decline. These results indicate that soil macro-invertebrate community is sensitive to water table decline in the Zoige peatland. Given the recognized importance of soil fauna to ecosystem functioning, more attention should be paid to the conservation of peatlands.

Carbon stock in litter of middle taiga forest ecosystems of Central Siberia

Litter plays an important role in the carbon cycle of forest ecosystems incorporating significant amount of carbon as a result of annual partial die-off of the biomass and releasing it during complex multistage processes of organic matter decomposition. The balance of these processes in the forests of permafrost zone significantly shifts towards the accumulation of dead organic matter. That makes the assessment of litter stock in these ecosystems particularly relevant, especially in relation to the predicted consequences of climate change in the study region. On the territory of middle taiga of Central Siberia, 14 sampling plots were established in the various landforms (slopes of different exposition, lowlands and uplands). The carbon stock in litter of the main forest types of the studied area varied from 0.47 to 4.46 kgC/m2. Also, the paper considers composition of litter accumulated in these ecosystems, including the ratio between fresh litterfall, fermented and humified plant residues, and dead roots. Our results demonstrated that fermented plant residues prevailed in the litter composition in most types of studied forest ecosystems due to specificity of hydrothermal regime and quality of litterfall. The results obtained might be applied to refine the carbon budget of Siberian forests.

Origin, migration and secondary processes of oil and natural gas in the western part of the Polish Outer Carpathians: geochemical and geological approach

The origin, migration pathways, as well as the influence of secondary processes of oil and natural gas accumulated in lower Cretaceous to lower Miocene strata of the western part of the Polish Outer Carpathians (between Kraków and Pilzno towns) based on results of organic geochemical analyses are investigated in this paper. Oil and thermogenic hydrocarbon gases were generated mainly from type II kerogen, and type II and III kerogen mixed in various proportions. These kerogens mainly occur in the Oligocene Menilite beds of the Silesian and Dukla nappes. Oils were generated from early to late “oil window”. Secondary cracking was recorded in oils from Dukla nappe, other secondary processes including biodegradation, water washing and evaporative fractionation were also developed to a various extent in many oils. The most biodegraded oils occur in seep S-Li, and the most extensive water washing is observed in the oil from seep S-Sa/1. The evaporative fractionation processes most significantly occur in the selected deepest parts of the multi-horizontal Biecz field. Hydrocarbon gases originated during both microbial and thermogenic processes of organic matter transformation. Natural gas has not been subjected to biodegradation processes. Carbon dioxide is derived from both microbial and thermogenic decomposition processes of organic matter and was generated together with hydrocarbon gases.

The Soil Chemical Properties Influencing the Oribatid Mite (Acari; Oribatida) Abundance and Diversity in Coal Ash Basin Vicinage

The samples of two technogenic sediments (MOS, coal ash sediment; MOD, a mixture of ash and natural soil) and two natural soils (MOM, meadow; MOF—forest; both Cambisol Dystric) in the vicinage of the coal ash basin were studied. We evaluated risk element concentrations and select-ed chemical and microbiological parameters to determine their influence on the community structure of Oribatida. High concentrations of various toxic elements, alkaline pH, and low hu-midity negatively affected the abundance of oribatid mites. The microbial indicator values showed that the soil microbial community formed in technogenic sediments could effectively use organic carbon. However, considering the wide C/N ratio of the substrates, the process of soil organic matter (SOM) decomposition was slowed down, and thus nutrients were less available for the mites, which could be among the reasons why we did not find any individual of oribatid mite in MOS. In MOD, however, we found representatives of three species, but only Tectocepheus velatus sarekensis established an abundant community at the highly contaminated site. Anthropogenic pressure resulted in the selection of r-strategists, which became dominant and reduced the whole community’s species’ diversity. Therefore, we consider it a suitable indicator of improper human intervention in the ecosystem.

Biogas residues in the battle for terrestrial carbon sequestration: A comparative decomposition study in the grassland soils of the Greater Region

The recycling of biogas residues resulting from the anaerobic digestion of organic waste on agricultural land is among the means to reduce chemical fertilizer use and combat climate change. This in sacco decomposition study investigates (1) the potential of the granulated biogas residue fraction to provide nutrients and enhance soil carbon sequestration when utilized as exogenous organic matter in grassland soils, and (2) the impact of different nitrogen fertilizers on the organic matter decomposition and nutrient release processes. The experiment was conducted in two permanent grasslands of the Greater Region over one management period using rooibos tea as a comparator material. The decomposition and chemical changes of the two materials after incubation in the soil were assessed by measuring the mass loss, total carbon and nitrogen status, and fibre composition in cellulose, hemicellulose and lignin. Overall, after the incubation period, granulated biogas residue maintained up to 68% of its total mass, organic matter and total carbon; increased its content in recalcitrant organic matter by up to 45% and released 45% of its total nitrogen. Granulated biogas residue demonstrated resilience and a higher response uniformity when exposed to different nitrogen fertilizers, as opposed to the comparator material of rooibos tea. However, the magnitude of fertilizer-type effect varied, with ammonium nitrate and the combinatorial treatment of raw biogas residue mixed with urea leading to the highest organic matter loss from the bags. Our findings suggest that granulated biogas residue is a biofertilizer with the potential to supply nutrients to soil biota over time, and promote carbon sequestration in grassland soils, and thereby advance agricultural sustainability while contributing to climate change mitigation.