Our Environment: Soil Ecosystems

2005 ◽  
pp. 77-118
Keyword(s):  
2017 ◽  
Vol 5 (2) ◽  
pp. 132-140 ◽  
Author(s):  
Kewat Sanjay Kumar ◽  

Mechanisms governing carbon stabilization in soils have received a great deal of attention in recent years due to their relevance in the global carbon cycle. Two thirds of the global terrestrial organic C stocks in ecosystems are stored in below ground components as terrestrial carbon pools in soils. Furthermore, mean residence time of soil organic carbon pools have slowest turnover rates in terrestrial ecosystems and thus there is vast potential to sequester atmospheric CO2 in soil ecosystems. Depending upon soil management practices it can be served as source or sink for atmospheric CO2. Sustainable management systems and practices such as conservation agriculture, agroforestry and application of biochar are emerging and promising tools for soil carbon sequestration. Increasing soil carbon storage in a system simultaneously improves the soil health by increase in infiltration rate, soil biota and fertility, nutrient cycling and decrease in soil erosion process, soil compaction and C emissions. Henceforth, it is vital to scientifically explore the mechanisms governing C flux in soils which is poorly understood in different ecosystems under anthropogenic interventions making soil as a potential sink for atmospheric CO2 to mitigate climate change. Henceforth, present paper aims to review basic mechanism governing carbon stabilization in soils and new practices and technological developments in agricultural and forest sciences for C sequestration in terrestrial soil ecosystems.


Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 218
Author(s):  
Cameron M. Ogilvie ◽  
Waqar Ashiq ◽  
Hiteshkumar B. Vasava ◽  
Asim Biswas

Plant roots are an integral part of soil ecosystems and contribute to various services, including carbon and nutrient cycling, weathering, and soil formation. They also modify soil physical properties (e.g., soil water content, pore size distribution, and bulk density) and impact subsequent crops’ growth. Cover crops have been reported to improve soil and environmental quality by reducing nutrient losses, improving soil water content, and increasing soil organic matter. Understanding the complex interactions between cover crop roots and soil (RS) is of utmost importance. However, cover crop RS interactions have not been critically reviewed. In this article, we investigated the nature of cover crop physical RS interactions and explored the emerging technologies for their study. We also assessed technologies that may be readily applied to the study of physical RS interactions in cover crop systems and discussed ways to improve related research in the future.


Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 378
Author(s):  
Inka Marie Willms ◽  
Maja Grote ◽  
Melissa Kocatürk ◽  
Lukas Singhoff ◽  
Alina Andrea Kraft ◽  
...  

Antibiotic resistance genes (ARGs) in soil are considered to represent one of the largest environmental resistomes on our planet. As these genes can potentially be disseminated among microorganisms via horizontal gene transfer (HGT) and in some cases are acquired by clinical pathogens, knowledge about their diversity, mobility and encoded resistance spectra gained increasing public attention. This knowledge offers opportunities with respect to improved risk prediction and development of strategies to tackle antibiotic resistance, and might help to direct the design of novel antibiotics, before further resistances reach hospital settings or the animal sector. Here, metagenomic libraries, which comprise genes of cultivated microorganisms, but, importantly, also those carried by the uncultured microbial majority, were screened for novel ARGs from forest and grassland soils. We detected three new beta-lactam, a so far unknown chloramphenicol, a novel fosfomycin, as well as three previously undiscovered trimethoprim resistance genes. These ARGs were derived from phylogenetically diverse soil bacteria and predicted to encode antibiotic inactivation, antibiotic efflux, or alternative variants of target enzymes. Moreover, deduced gene products show a minimum identity of ~21% to reference database entries and confer high-level resistance. This highlights the vast potential of functional metagenomics for the discovery of novel ARGs from soil ecosystems.


2013 ◽  
Vol 10 (7) ◽  
pp. 5115-5124 ◽  
Author(s):  
J. Esperschütz ◽  
C. Zimmermann ◽  
A. Dümig ◽  
G. Welzl ◽  
F. Buegger ◽  
...  

Abstract. In initial ecosystems, concentrations of all macro- and micronutrients can be considered as extremely low. Plant litter therefore strongly influences the development of a degrader's food web and is an important source for C and N input into soil in such ecosystems. In the present study, a 13C litter decomposition field experiment was performed for 30 weeks in initial soils from a post-mining area near the city of Cottbus (Germany). Two of this region's dominant but contrasting pioneering plant species (Lotus corniculatus L. and Calamagrostis epigejos L.) were chosen to investigate the effects of litter quality on the litter decomposing microbial food web in initially nutrient-poor substrates. The results clearly indicate the importance of litter quality, as indicated by its N content, its bioavailability for the degradation process and the development of microbial communities in the detritusphere and soil. The degradation of the L. corniculatus litter, which had a low C / N ratio, was fast and showed pronounced changes in the microbial community structure 1–4 weeks after litter addition. The degradation of the C. epigejos litter material was slow and microbial community changes mainly occurred between 4 and 30 weeks after litter addition to the soil. However, for both litter materials a clear indication of the importance of fungi for the degradation process was observed both in terms of fungal abundance and activity (13C incorporation activity)


2010 ◽  
Vol 67 (6) ◽  
pp. 743-746 ◽  
Author(s):  
Rafael Leandro Figueiredo de Vasconcellos ◽  
Mylenne Calciolari Pinheiro da Silva ◽  
Carlos Marcelo Ribeiro ◽  
Elke Jurandy Bran Nogueira Cardoso

Actinobacteria are capable of playing several different roles in soil ecosystems. These microorganisms affect other organisms by producing secondary metabolites and are responsible for the degradation of different complex and relatively recalcitrant organic compounds. In our survey of actinobacteria isolated from the rhizosphere of Araucaria angustifolia, five culture media (AI, WYE, YCED, MSSC and LNMS) were compared for their effectiveness in isolating these microorganisms. When summing up all the isolates randomly obtained, we got 103 isolates. After isolation, the phosphate-solubilizing ability and the "in vitro" production of indole-acetic acid and chitinases were evaluated. The AI medium was ineffective for actinobacteria isolation, when it was compared with the other four culture media. Indole-acetic acid and chitinase were produced by respectively 36% and 24% of the strains tested. However, only 2% of the 103 strains presented some phosphate-solubilizing ability. These results demonstrate the biotechnological potential of these microorganisms.


Author(s):  
T.I. Висоцька ◽  
Т.В. Пічкур

The article studies the impact of persistent organic pollutants (POPs) on the environment. POPs are artificial substances for the environment. Nowadays, scientists have created more than 18 million chemical compounds, almost 100 000 of which are used in industry. It is widely understood that the pollution of the environment by persistent organic pollutants is due to their constant movement between the natural envelopes. Environmental studies show that regardless of sources (POPs) all the components of the biosphere are under their negative influence: surface water and groundwater, atmosphere, soil ecosystems, flora, and fauna. Measures that can be taken to prevent and reduce the impact of POPs on human health are conventionally divided into measures applied at the state level, and measures for the health maintenance, which should be used by each person, possessing certain knowledge about potential sources and properties of persistent organic pollutants. Considering the fact that POPs can remain in the environment for a long time, there is only one way to protect ourselves and future generations – it is to stop the production and use of POPs and to stop those production processes that use POPs. But this requires the efforts of the world community.


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