Biotic Components Research Articles

ECOLOGICAL WATER QUALITY

Water quality – is a description of water’s chemical and biological composition and physical properties, which characterize it as an abiotic component of aquatic ecosystem and determine its suitability for specific consumption purposes.
 Ecological water quality (environmental water quality) – refers to the ecological well-being of an aquatic ecosystem, with the main focus on protection of the aquatic environment and human life and health. It comprises a complex of physical, chemical, biological and other parameters reflecting specific features of abiotic and biotic components of aquatic ecosystems.
 The requirements for physical, chemical and biological properties of water are set in the water quality standards, which may be developed by particular countries or introduced by international organizations.
 Ecological water quality depends upon natural and human factors. Natural factors are in their turn divided into abiotic (for example, geological, meteorological, hydrological) and biotic (for example, the ratio of primary production and organic matter destruction). The main human factors affecting water quality include artificial modification of aquatic ecosystems’ hydrological conditions and their pollution with diverse chemical compounds.
 There are a lot of approaches to ecological water quality assessment according to both abiotic (physical and chemical) and biological parameters. Physical and chemical methods take into account such parameters as water transparency, suspended particulate matter concentration (turbidity), ion composition, water hardness, total dissolved salts content, nutrients and organic matter content, dissolved gases concentration, pH. Biological methods are based upon assessing the living organisms’ (biological indicators’) response to mineral and organic substances, present in water. Various living organisms can be used as biological indicators: algae, in particular – diatoms, higher aquatic plants, different species of aquatic invertebrates and fishes. While physical and chemical methods characterize water quality at the moment of sampling, biological methods provide an integral picture of water quality for a certain time period. Besides, biological methods are more informative, because they reflect the aquatic ecosystem’s response to pollution.
 On the whole, the most reliable data on ecological water quality can be obtained by combining physical, chemical and biological methods.

SPECIES DIVERSITY OF THE FLORA OF THE WESTERN HLYNIANSKA AREA OF THE DUBRIVSKE PRIMARY KAOLIN DEPOSIT

We describe the results of the study of the flora of regenerated and transformed vegetation on the territory of the Zahidno-Glynske section of the Dubrivske deposit of primary kaolin. The authors determined the species composition of higher vascular plants and mosses in the studied area. They made a brief analysis of the ecological features of the distribution of individual species or their systematic groups. They also made a short analysis of the ecological features of the distribution of individual species or their systematic groups. In particular, we established a connection between the features of the ecosystem structure and the ratios of representatives of different plant families, and also constructed a syntaxonomic scheme of plant groups based on the principles of the Brown- Blanke ecological and floristic school. During the research, we discovered 151 representatives of the flora. Among them are 143 species of higher vascular plants from 33 families and 9 species of mosses from 7 families. The most numerous are the families Poaceae (24 species), Asteraceae (21 species), Rosaceae (14 species), and Fabaceae (10 species). The vegetation of the studied area belongs to 13 classes, 19 orders, 35 unions, and 40 associations. There is an active restructuring of settlements with constant reformatting of the econiche packaging during the process of natural restoration of the vegetation cover with the help of primary autogenous successions. Empty econiches are formed here. They can potentially be inhabited, both by rare representatives of biota and habitats and by dangerous synanthropic species. For example, these habitats become vulnerable to the introduction of invasive species of transformers, which threaten rare biota components, ecosystem stability processes, agriculture, and human health. In this regard, territories, where active mineral extraction is carried out or restored after its termination, should be under constant monitoring regarding floristic and phytocenotic diversity. No species included in the IUCN Red List, the European Red List, annexes, and resolutions to the Berne Convention, Red Book of Ukraine, and to the list of regionally rare species were found on the territory. The invasive species-transformer Solidago canadensis was located on the territory. It is in the early stages of penetration and transformation of habitats of renewable natural vegetation.

An Agenda for Research of Uncovered Epidemiological Patterns of Tick-Borne Pathogens Affecting Human Health.

The panorama of ticks and tick-borne pathogens (TBP) is complex due to the many interactions among vertebrates, vectors, and habitats, occurring at different scales. At a broad spatial range, climate and host availability regulate most tick processes, including questing activity, development, and survival. At a local scale, interactions are obscured by a high indeterminacy, making it arduous to record in field surveys. A solid modelling framework could translate the local/regional empirical findings into larger scales, shedding light on the processes governing the circulation of TBP. In this opinion paper, we advocate for a re-formulation of some paradigms in the research of these outstanding cycles of transmission. We propose revisiting concepts that faced criticisms or lacked solid support, together with the development of a conceptual scheme exploring the circulation of TBP under a range of conditions. We encourage (i) an adequate interpretation of the niche concept of both ticks and vertebrate/reservoir hosts interpreting the (a)biotic components that shape the tick's niche, (ii) an assessment of the role played by the communities of wild vertebrates on the circulation of pathogens, and (iii) the development of new approaches, based on state-of-the-art epidemiological concepts, to integrate findings and modelling efforts on TBP over large regions.

Taxonomic Diversity and Selection of Functional Traits in Novel Ecosystems Developing on Coal-Mine Sedimentation Pools

Coal-mine sedimentation pools are extrazonal habitats in which the anthropogenic changes of all historic, abiotic, and biotic components, followed by conditions of extreme environmental stress, lead to the formation of novel ecosystems. Our study aims to (i) classify the vegetation on the basis of floristic and ecological criteria, (ii) detect the main environmental gradients responsible for the diversity of vegetation, and (iii) present the selection of species’ functional traits along environmental gradients. A cluster analysis of the floristic data revealed 14 distinct combinations of species. Short- and long-lived ruderals, meadow, xerothermic, and psammophilous species make up the floristic composition of vegetation. A canonical correspondence analysis on the floristic data and average Ellenberg’s indicator values confirmed moisture, soil reaction, and salinity as the main gradients, while fertility and insolation were secondary gradients shaping the diversity of vegetation. A RLQ with a subsequent cluster analysis revealed four groups of species traits selected along environmental gradients. These differed with reference to morphological (canopy height) and physiological traits (specific leaf area, or SLA), as well as persistence (life span), regeneration (reproduction by seeds or vegetative reproduction), and dispersal functional traits. This knowledge can be crucial when planning the restoration of these sites by using spontaneous succession and learning how the various environmental resources can be used to restore or provide new ecosystem services.

Diversity of culturable bacteria of freshwater environments from an altitudinal gradient in the eastern Cordillera of Colombia.

Bacteria are an essential biotic component in freshwater environments. A group of 262 bacterial strains of freshwater environments from an altitudinal gradient in the Eastern Cordillera of Colombia was identified using the 16S rRNA gene sequence analysis. Hill numbers and related diversity indices were calculated to know the bacteria diversity in this collection and environments. In addition, the Bray-Curtis index was also calculated to know the differences in genera composition between sampled localities and their relationship with altitudinal gradient. The identified bacterial strains were grouped into 7 major phylogenetic groups (Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Flavobacteriia, Actinomycetes, Clostridia, and Bacilli), 38 genera, and 84 distinctive species. Diversity analysis based on Hill numbers showed that the diversity concerning bacteria inhabiting freshwater environments was consistently high. Dominant genera were Klebsiella, Serratia, and Pseudomonas, although other genera such as Bacillus, Lelliottia, and Obesumbacterium were well represented per locality. The highest bacterial diversity came from localities Cimitarra and El Carmen del Chucurí, while those originating from Santa Bárbara and Páramo del Almorzadero were relatively lower diverse. Differences in diversity were found to be mainly due to the spatial replacement of one genus by another and, to a lesser extent, to the loss or gain of taxa.

Biotic sound SNR influence analysis on acoustic indices

In recent years, passive acoustic monitoring (PAM) has become increasingly popular. Many acoustic indices (AIs) have been proposed for rapid biodiversity assessment (RBA), however, most acoustic indices have been reported to be susceptible to abiotic sounds such as wind or rain noise when biotic sound is masked, which greatly limits the application of these acoustic indices. In this work, in order to take an insight into the influence mechanism of signal-to-noise ratio (SNR) on acoustic indices, four most commonly used acoustic indices, i.e., the bioacoustic index (BIO), the acoustic diversity index (ADI), the acoustic evenness index (AEI), and the acoustic complexity index (ACI), were investigated using controlled computational experiments with field recordings collected in a suburban park in Xuzhou, China, in which bird vocalizations were employed as typical biotic sounds. In the experiments, different signal-to-noise ratio conditions were obtained by varying biotic sound intensities while keeping the background noise fixed. Experimental results showed that three indices (acoustic diversity index, acoustic complexity index, and bioacoustic index) decreased while the trend of acoustic evenness index was in the opposite direction as signal-to-noise ratio declined, which was owing to several factors summarized as follows. Firstly, as for acoustic diversity index and acoustic evenness index, the peak value in the spectrogram will no longer correspond to the biotic sounds of interest when signal-to-noise ratio decreases to a certain extent, leading to erroneous results of the proportion of sound occurring in each frequency band. Secondly, in bioacoustic index calculation, the accumulation of the difference between the sound level within each frequency band and the minimum sound level will drop dramatically with reduced biotic sound intensities. Finally, the acoustic complexity index calculation result relies on the ratio between total differences among all adjacent frames and the total sum of all frames within each temporal step and frequency bin in the spectrogram. With signal-to-noise ratio decreasing, the biotic components contribution in both the total differences and the total sum presents a complex impact on the final acoustic complexity index value. This work is helpful to more comprehensively interpret the values of the above acoustic indices in a real-world environment and promote the applications of passive acoustic monitoring in rapid biodiversity assessment.

Biorefineries development from agricultural byproducts: Value addition and circular bioeconomy

The increase in the human population in the world, industrialization, and rapid urbanization creates a big challenge for the agricultural revolution. Hence, to enhance the crop's productivity modern agricultural technology, hybrid seeds; management of full irrigation facilities, and the use of various fertilizers, and pesticides are being adopted. Though such advanced techniques enhance productivity, they also produce a huge amount of agro-waste. The proper waste management of such wastes is a headache for the farmers due to the lack of dumping lands, proper transportation, removal facilities, and lack of planned utilization. Since direct burning of the wastes do air, water, and soil pollution, a systematic utilization of these cheap wastes for the development of value-added products and chemicals will promote a clean and healthy environment for the biotic and abiotic components. A proper, efficient, and effective treatment system can break down waste biomass into simple forms and can be easily consumed by our natural and engineered microbial systems to produce bio-chemicals and bio-fuels. Value-added products from agro wastes are now needed every hour as far as the sustainable production of energy and biochemical is an important concern. Agro-waste utilization-based biorefineries can provide a big pillar for the development of a circular bio-economy. The review emphasizes the value-added products generated from agricultural byproducts/waste residue's utility, towards sustainability and a clean environment.

Airborne Dust and Associated Metals: A Link between its impact and sink rate within different roadside plants

<p>Transportation driven by fossil fuels increases air pollution induced by urbanisation. Heavy metals such as Cadmium (Cd), Chromium (Cr), Copper (Cu), Iron (Fe), Lead (Pb), and Zinc (Zn) are life-threatening elements and their concentration is increasing alarmingly in soil in various countries. Air pollution and associated metals contaminate the environment and affect nature's abiotic and biotic components. The significance of tree species originates from their connection to the effects of pollution and the solution approach to their biological cycle. Nineteen distinct tree species dominate the region, with heavy metals sinking in the range of Cd<0.4, Cr<1, Cu<15, Fe<2, Pb<5, and Zn<2 mg/kg or parts per million. According to the findings of this study, tree species can sink heavy metals. The different trees have distinct metals-sink ratios. The competence results showed the order of heavy metal sink as Delonix Regia-red (4) > Delonix Regia-yellow (4) > Syzygium Cumini (3) > Muntingic Calabura (3) of the trees with the highest sink rates and nine species had absorbed lead metal. The nine tree species were unsuitable for heavy metal absorption or deposition. There, Albizia Lebbeck (T02), Biancaca Decapetela (T05), Brucea Javanica (T06), Ficus Elastica (T09), Ficus Religiosa (T10), Pithecellobium Dulce (T13), Tamarind (T17), Terminalia Catappa (T18), and Thespesia Populnea (T19) were very low, less than 10% of other dominant tree species. Syzygium cumini (T16) is a high-yielding tree species that absorb significant quantities of Lead (Pb) and Copper (Cu). These studies confirm that, tree species can capture several heavy metals simultaneously from the polluted environment.</p>

Monitoring rainfall events in desert areas using the spectral response of biological soil crusts to hydration: Evidence from the Gurbantunggut Desert, China

Biological soil crusts (biocrusts) are essential biotic components in desert ecosystems, yet they are vulnerable to climate change, especially changes in precipitation. Unfortunately, the scarcity and unreliable performance of mainstream precipitation products in desert regions has prevented further research on the responses of desert ecosystems to climate change scenarios. By taking advantage of the spectral sensitivity of biocrusts to hydration, this study aims to examine the potential to monitor rainfall events using the spectral response of biocrusts. First, BRDF harmonization enhanced the rainfall-induced spectral response. Then, a detectability analysis was performed to clarify how influential factors affect the spectral response. Finally, a random forest (RF) model was developed to derive the temporal dynamic and spatial pattern of detectable rainfall events. The results show that rainfall events induce significant changes in biocrust spectra, especially within some spectral bands (i.e., SWIR, Red, and Blue) and indices (i.e., BSCI and NDVI). A rainfall event is detectable if the precipitation amount is >6 mm and recorded by satellites within 24 h. The RF model performs better (F1 score = 0.78) than the mainstream precipitation products (F1 score between 0.19 and 0.52) in temporal monitoring. Additionally, the model can delineate the spatial pattern of rainfall events well. These findings imply that this phenomenon has great potential for application in rainfall monitoring in desert areas, which could greatly contribute to understanding the mechanisms of desert ecological processes on a large scale.

Biostrategies for the removal of microplastics: A Review

Recent studies on plastic pollution have shown that microscopic plastic particles or microplastics are ubiquitous. Both abiotic and biotic components are affected by microplastics. There are several ways to get rid of microplastics, that include recycling, landfilling, incineration, and biodegradation. Biodegradation is still a widely used remediation technology due to its significant economic and environmental benefits. One or more bio-cultures, such as bacteria, mould, yeast, and algae, can be used for biodegradation. In this review, we look through the contributions of microorganisms in biodegradation and other biotechnological techniques to speed up the process.

Developing understanding of biotic turnover

Over the last 50 years A.A. Titlyanova with her colleagues from the Laboratory of Biogeocenology in the Institute of Soil Science and Agrochemistry of the Siberian Branch of the Russian Academy of Sciences has been actively studying biotic turnover components and processes: the flow of carbon and its stocks in various ecosystem blocks were estimated, and turnover regimes revealed. The performed field experiments showed that the nearer an ecosystem is to the stationary state, the more closed its biotic turnover becomes, and the lesser role is played by abiotic processes. The studies in diverse ecosystems confirmed that climatic and weather conditions, soil properties as well as ecosystem’s relief position and exposition are the main factors driving the net primary production of grassland ecosystems. The article presents and discuss earlier results about phytomass dynamics and provides estimates of the net primary production, both above- and belowground. The belowground plant organs, i.e. roots and rhizomes, preserve life of a grassland ecosystem under any climatic conditions. Sustainability of grasslands in time depends on the changes in plant species composition, diverse survival strategies, high productivity of the dominant plant species, soil seed bank and their aeolian and water transportation from other ecosystems, rapid release of nutrients from residues by mineralization. Analysis of different successions in ecosystems allowed concluding that the number of succession types is higher than only two main types of primary and secondary succession. The primary succession refers only to those successions that occur by spontaneous revegetation at sites without any history of previous vegetation, whereas the secondary successions are more diverse and include pyrogenic (renovating succession), pasture (continuous and reversible), abandoned field successions and others. Not only the biotic turnover, but strong in- and outcoming flows of matter and energy operate in each and every ecosystem. Presently turnover can be better described as a network of diversified processes, rather than a circle per se.

Office Sustainability Assessment for Endearing Resilience in an Academic Environment

Office conditions are crucial to assessing the sociocultural, economic, environmental and public health of the majority of the urban population. The office is a built environment that takes up the bulk of the time and energy of society's elite. As such, the quality of office spaces has a significant effect on the health, comfort, satisfaction and productivity of office workers. No doubt, inadequate indoor environmental quality will impede workers' productivity and well-being. Sustainability in the office addresses the interface through which resilience in both the biotic and abiotic components of the indoor working micro-environment can be measured and transformed for full productivity. In the light of this, this article evaluates the factors driving infrastructural, health and economic resilience in academic institutions. The study reviews the literature on the theory of human behaviour, with a view to establishing the link between key concepts in infrastructural, health and economic resilience and office sustainability within an academic environment. It identifies office sustainability as a major determinant in the effective measurement and development of resilience in academic environments. It was observed that the dimensions of infrastructural, health and economic resilience are in-built features which academic institutions should adopt to achieve overall resilience in the academic environment. This assessment should bring about major social and economic benefits, given the quantum of time that members of the university staff spend in their offices

Scavenging Of Waste Water Using Oyster Mushrooms

Water contamination is a never-ending perpetual trouble and ruefully its a result of urbanization, industrialization along with population expansion, and other ancillary factors. Environmental deterioration had always impacted negatively on both biotic and abiotic components. The major impact of it had serious consequences on one of the pivotal natural resource- water. In addition to the agony of water scarcity the lack of treatment of wastewater in third world countries causes challenges and thus reuse and recycling becomes the only way out of the predicament. The challenge however lies to create cost effective, simpler, user-friendly technologies that prevent endangering the significant water-dependent livelihoods while also protecting our priceless natural resource. The best technique apart from conventional chemical techniques is to take resort to green bioremediation involving mushrooms and recycle the waste therein. Mushrooms growing on natural materials such as wheat straw, rice straw, and other agricultural wastes are been used for a long time as a nutritional ingredient being laden with rich protein content. Mushroom are also seen to be an effective bioremediation tool of their usage in the removal of an array of contaminants. These are easy to cultivate and has the propensity specifically to store a lot of heavy metals and other harmful compounds. Oyster mushrooms has been reported to act as “scavengers” of the environment by digesting dead wood, rejuvenating the soil and providing minerals in usable form to the ecosystem. This review highly rests on the importance of oyster mushrooms where extracellular oxidative enzymes produced by the mushrooms can be used to degrade a wide range of notorious chemicals and substances that pollute the environment.

Soil health through farmers’ eyes: Toward a better understanding of how farmers view, value, and manage for healthier soils

Improved soil health (SH) is critical in achieving agricultural resilience and mitigating climate risks. Whether SH management practices are widely used depends greatly on US farmers’ voluntary decision-making. Toward understanding this point, much research has addressed factors that contribute to the adoption (or lack thereof) of SH-promoting practices, but less is known in terms of farmers’ perceptions of SH itself and the corresponding management practices they see as related to achieving SH. To offer introductory insight on this knowledge gap and support better buy-in from farmers toward positive SH outcomes, our research draws upon qualitative interviews with 91 farmers across three key agricultural states in the Midwest (Illinois, Indiana, and Michigan). We develop a more detailed understanding of farmers’ views on SH, and why and how they manage for it. Nearly all interviewed farmers were familiar with the concept of SH and most viewed it favorably. A minority of farmers lacked familiarity with the term “SH” yet still managed for it. Skeptics of SH largely cited uncertainties related to over-zealous messaging by proponents of SH or lack of evidence for the return on investment of SH practices. Overall, farmers’ perceptions of SH largely aligned with the scientific community’s understanding of soils being a dynamic system, though farmers most dominantly defined SH by its biological component. Farmers perceived a host of benefits of SH, most often noting benefits to production, followed by improvements in physical aspects of the soil such as erosion control and increased organic matter. Notably, production and sustainability benefits were often cited together, suggesting that SH management is increasingly seen as a “win-win” by farmers. Additionally, we found that many farmers view themselves as active participants in SH outcomes and believe their management choices are indicators of positive SH outcomes, regardless of the practices they employ, including some strategies (such as tillage or tile drainage) that do not align with scientifically documented approaches to improving SH. Our findings show that farmers report engaging in an array of SH management practices that target both biotic and abiotic components of soils, and often use multiple practices in tandem to promote SH on their farms. Achieving better SH in agricultural production in the future will require engaging farmers in SH management by tailoring outreach and communication strategies to align with the perspectives and language farmers themselves use to conceptualize SH.

Phosphate Solubilizing Bacteria: A potential biotic component for solubilizing phosphate in soil and its application as Biofertilizer: A Review

The number of populations is increasing day by day. As populations no is being increased, the demand of food is also increasing simultaneously. Therefore, it’s easy to understand that no. of population growing is directly proportional to the demand of food. To increase the yield of food crops a large amount of chemical fertilizers is used every year. But certainly, these chemical fertilizers can cause long term damage to environment as well as on the bodies of those who will consume the grains also. In that case definitely we have to think some alternatives of chemical or artificial fertilizers. In addition, in spite of presence of sufficient amount of phosphate in soil, plant can’t get the access of phosphate as it forms complex with either inorganic metal ion or various organic compounds. On that note scientists and researchers have studied some microorganisms which can play very significant role in this critical situation. This microorganism live in rhizosphere region of plant and can increase soil fertility by solubilizing phosphate and also help in the development of plant. These are known as Phosphate Solubilizing Bacteria (PSB). This review discussed the different species of PSB, the mechanisms they follow to solubilize phosphate, their role in plant development. This research review also focuses on use of phosphate solubilizing bacteria for sustainable agricultural purpose.

Mycological composition of soils in Kuban rice agrocenoses as a biotic component for their health

Studies of the water-physical, physical-chemical and biological properties of meadow-chernozem soils were carried out on a rice irrigation system located in the present-day delta of the Kuban River. Rice meadow-chernozem soils have good water and general physical properties of humus layers. An increase in compaction is observed in the lower horizons of these soils. Meadow-chernozem soils are distinguished by low content of organic matter in arable horizons (3,2-3,4 %), neutral reaction of soil solution (рН 6,8-6,9) and high indices of cation exchange capacity (38,7-39,1 mmol/100g). The mycological composition of the studied soils in the autumn-spring periods was identified and identified. The soil was more saturated with representatives of the suppressive group at the beginning of rice vegetation, the opportunistic group was not detected and the antiphytopathogenic potential was 1:2. The spring-fed rice crop rotations soils are prone to soil stresses that are oversaturated with suppressors. In autumn, the ratio of conditionally suppressive to saprotrophic and pathogenic mycota was 1.5:4.5:7. The growth of colonies of the micromycete genus Trichoderma is traced, which confirms the beginning of a long process and the slow recovery of soil degradation processes.

The use of biospheric monitoring in the study of reservoirs in the Volga-Don interfluve of Russia

With anthropogenic activity, as well as with changes in climatic, hydrological and landscape regimes, significant structural and spatial shifts occur in existing ecosystems. The deterioration of water quality also significantly affects the state of coastal water zones, structural and species composition. In the course of monitoring the Tsimlyansk reservoir using the AQUA-1 automated watercraft, the quality of natural water was determined, formalized relationships between the abiotic and biotic components of the ecosystem were identified, the ecological state of the water intake zone was predicted, and the functioning of a number of structures that affect the regime and level of the reservoir. In order to improve the quality of water intake water, bioremediation was carried out using the planktonic microalgae Chlorella vulgaris, calculations of the invasion were made using computer programs. On the basis of the conducted monitoring studies, a hydrodynamic model of the reservoir bay was compiled, a model of an automated watercraft for biospheric monitoring was developed, an optimized scheme for the introduction of Chlorella vulgaris into the reservoir. The main biological indicators-indicators of water intake zones have been established, taking into account changes in the hydrological regime. The positive impact of the environmentally safe bioremediation of water at the water intakes of the Tsimlyansk reservoir in order to improve the quality of natural water used for drinking purposes and fish farming is shown.

IMPACT OF ACID RAIN ON THE ENVIRONMENT

The article touches on the topic of acid rain, which poses a serious threat to the environment. The idea is substantiated that the presence in the atmosphere of certain acid-forming compounds, primarily sulfuric and nitric acids, formed as a result of the chemical interaction of sulfur and nitrogen oxides with atmospheric water vapor, can lead to acidification of rainwater. It is noted that the interaction of acid rain and ecosystem elements leads to a disruption of the equilibrium processes occurring in the biosphere. Considerable attention is paid to the decrease in soil fertility as a result of acid precipitation, which leads to the leaching of vital plant substances from the soil and ultimately causes forest degradation. The article, due to acid precipitation and disruption of the natural cycle of substances, also analyzes the harmful effects of acidified precipitation on the biocenoses of closed water bodies (flora, fauna). It is emphasized that the disturbance caused by acid rain, having a negative impact, spreads to various abiotic and biotic components of the ecosystem. The purpose of the article is to analyze the study of the origin and negative consequences of acid rain, as well as to evaluate efforts to combat the negative impact of acid rain on the environment. Keywords: acid rain, forests, plants, soils, consequences.

Study of aquatic insects, their role in improving biodiversity and balancing the food web of a freshwater ecosystem at Karadkhed Dam in Nanded, Maharashtra

Fresh water ecosystem plays very crucial role in ecology and it maintain ecological balance of flora and fauna on the earth. Aquatic insects are among the most diverse groups of animals of especially in the fresh water ecosystem. Aquatic and terrestrial food chains both include aquatic insects as essential components. Due to their involvement in the energy and nutrient cycling through food chains and webs as well as their role in water purification, aquatic insects serve as the link between the aquatic and terrestrial ecology. The water quality Acts as a limiting factor for biotic components in an aquatic ecosystem. The aquatic biodiversity gets affected by several factors such as industrial pollution or anthropogenic activities. Present investigation is an attempt to document abundance and diversity of aquatic insects and the role of aquatic insects in the food web of a fresh water karadkhed dam, Nanded, Maharashtra. The study was carried out during 2021 to 2022, including the three seasons.

Detoxification and Removal of Hexavalent Chromium in Aquatic Systems: Applications of Bioremediation

Chromium is a transition metal with a wide range of applications in leather tanning, textile, electroplating, stainless steel production, inorganic chemical production and wood preservation industries due to yellow colouration, corrosion resistance, higher melting-point and crystalline structure with raging of oxidation states from 0 to +6. Trivalent and hexavalent chromium are the most abundant forms of chromium discharged into the aquatic environment by industries. It has been reported that hexavalent chromium is highly toxic than trivalent chromium due to the higher solubility, mobility and tendency to accumulate in higher trophic levels, which, therefore, become bioavailable and causes carcinogenic, mutagenic and teratogenic effects on most microorganisms and animals, growth inhibition, morphological and physiological changes and yield reductions in plants. Therefore, it is essential to detoxify the above hazardous pollutants up to permissible limits, which local and international authorities have legislated concerning its threat towards biotic components. Hexavalent chromium detoxification is possible to achieve using three methods i.e. physical, chemical and biological methods. These remediation processes can eliminate highly toxic hexavalent chromium or transform it into a less toxic form of trivalent chromium, completely or partially by adsorption and reduction. Biological remediation is considered a cost-effective and ecofriendly method compared to physical and chemical remediation. Further, many biological agents have been identified as agents that can tolerate the hexavalent chromium toxicity up to certain higher levels depending on the internal and external environmental factors, indicating different metal tolerance mechanisms that are assumed to be applied in metal remediation aspects. According to the testimonies of novel bioremediation studies, some hexavalent chromium tolerant organisms such as plants, bacteria, unicellular and multicellular fungi and algae are promising eco-friendly alternatives in detoxification and hexavalent chromium removal perspective. This article reviews the bioremediation approaches available for hexavalent chromium detoxification and removal and highlights the strengths and weaknesses of current bioremediation methods.