scholarly journals Diversité Et Dynamique Des Communautés De Vers De Terre De Trois Formations Végétales Dans Une Savane Humide De l’Afrique De l’Ouest (Lamto, Côte d’Ivoire)

2018 ◽  
Vol 14 (27) ◽  
pp. 281
Author(s):  
Soro Nounfro Madjima ◽  
Ehouman N’guetta Moïse ◽  
Toure Mamadou ◽  
Ouattara Noufou Doudjo ◽  
Tiho Seydou
Keyword(s):  
Organic Matter ◽  
Terrestrial Ecosystems ◽  
Tropical Soil ◽  
Ecosystem Functions ◽  
Soil Biology ◽  
Soil Organisms ◽  
Litter Biomass ◽  
Manual Sorting ◽  
Epigeic Earthworms ◽  
Endogeic Earthworms

The maintenance and stability of many terrestrial ecosystems are in part related to the ecosystem functions and services of soil organisms. The present study aims to evaluate the influence of litter biomass produced by three types of vegetation in the Lamto reserve on the dynamics of earthworm community. Each vegetation formations has been subdivided into 3 parcels. These parcels were geo-referenced using a GPS and mapped using QGIS software. For each plot, 25 points were randomly selected using their GPS coordinates. The litters were collected by manual collection to evaluate their biomass. Monoliths of the TSBF (Tropical Soil Biology) type were dug in order to collect the earthworms by direct manual sorting. Also, soil clumps were collected to determine the organic matter levels by the method of lossto-fire. In total, 12 species of earthworms belonging to 3 ecological categories were collected. The forest block had the highest density of earthworms with a predominance of epigeic earthworms followed by grassy savannah with a predominance of endogeic earthworms. The wooded savannah has the lowest density of earthworms with a predominance of anecic earthworms. In terms of species richness, the grassy savannah contained the greatest number of earthworm species followed by the wooded savannah and the forest block that had the same number of species. In the three vegetations formations, it was found that earthworm densities were correlated with litter biomass as well as organic matter levels (correlation between earthworm density and litter biomass: r 2 =0, 75; correlation between density of earthworms and the rate of organic matter: r 2 =0, 93).

Soil Biology and Microbiology

2003 ◽  
Author(s):  
Anthony S. R. Juo ◽  
Kathrin Franzluebbers
Keyword(s):  
Organic Matter ◽  
Food Web ◽  
Atmospheric Carbon Dioxide ◽  
Soil Fauna ◽  
Higher Plants ◽  
Vital Role ◽  
Soil Biology ◽  
Soil Organisms ◽  
Mineralization Of Organic Matter ◽  
Living Tissues

Soil organisms are fauna and flora that spend all or part of their life in the soil. They play a vital role in the maintenance of soil fertility through processes such as the accumulation of soil organic matter, soil aggregation, and the mineralization of organic matter which releases nutrients available to higher plants. Moreover, many antibiotics are produced from microorganisms isolated from soils. Soil fauna include macrofauna (> 2 mm in width, such as mice, earthworms, termites, and millipedes), through mesofauna (0.2-2 mm, such as collembola and mites), to microfauna (<0.2 mm, such as nematodes and protozoa). Soil flora include macroflora (such as the roots of higher plants), and microflora (such as algae, fungi, actinomycetes, and bacteria). The activities of soil fauna and flora are intimately related in what ecologists call a food chain or, more accurately, a food web. Higher plants play the role of primary producers by using water and energy from the sun, and carbon from atmospheric carbon dioxide to make organic molecules and living tissues. Soil organisms that eat live plants, such as mice or termites, are called herbivores. Most soil organisms, however, use the debris of dead tissues left by plants and animals (detritus) as their source of food, and are called detritivores. Soil organisms that consume live animals, such as centipedes, mites, spiders, or nematodes, are predators and are called carnivores. Some organisms that live off, but do not consume, other organisms are called parasites. Mycrophytic feeders are organisms that use microflora as their source of food, and include certain collembola, mites, termites, nematodes, and protozoa. The actions of soil fauna in the food web are both physical and chemical, while those of the microflora are mostly biochemical. The actions of mesofauna and macrofauna enhance the activities of the microflora in several ways. First, the chewing action fragments the litter to expose the more easily decomposed cell contents for microbial digestion. Second, the fragmented plant tissues are thoroughly mixed with microorganisms in the animal gut, where conditions are ideal for microbial action. Third, the mobile animals carry microorganisms with them and help them to disperse and find new food sources.

scholarly journals Effect of Different Agroecosystem on Earthworm Diversity in Azaguié Locality (Côte d'Ivoire)

2020 ◽  
Vol 11 (2) ◽  
pp. 327
Author(s):  
N’guetta Moïse Ehouman ◽  
Mamadou Touré ◽  
Pkan Pkan Kouakou Gains ◽  
Hervé Kouya Bi ◽  
Seydou Tiho
Keyword(s):  
Physicochemical Parameters ◽  
Terrestrial Ecosystems ◽  
The Other ◽  
Substantial Part ◽  
Rubber Plantation ◽  
Soil Biology ◽  
Manual Sorting ◽  
Physico Chemical ◽  
The Impact ◽  
The Relationship

In most terrestrial ecosystems, earthworms are considered to be excellent bioindicators of biodiversity and soil quality. However, their diversity and abundance encountered depend on the systems considered and on the anthropic pressure exerted. The objective of this study was to assess the impact of a land use on the earthworm community. Earthworms were collected in TSBF (Tropical Soil Biology and Fertility) type monoliths by the direct manual sorting method in three types of farms (fallow, rubber plantation and mangosteen plantation) in the locality of Azaguié. Measurements of the physicochemical parameters of the soil, in particular, the total organic carbon level, the organic matter rate, the nitrogen rate, the conductivity, the hydrogen potential (pH) and the total phosphorus were carried out at the Laboratory Central of Agrochemistry and Ecotoxicology (LCAE) from 200 g of clod of soil sampled in different monoliths. These studies showed that in all the plots analyzed, the endogeic polyhumic worms presented the highest densities while the epigeic detritivorous worms presented the lowest densities. The distribution of earthworms in the mangosteen plot was homogeneous, unlike that of the other plots. However, the physico-chemical parameters of the soils were higher in the fallow. The canonical correspondence analysis carried out to assess the relationship between the variability of the earthworm density of the plots and the physicochemical parameters measured showed that the physicochemical parameters measured explained only a substantial part of this distribution of earthworms while the other part is possibly linked to other environmental factors.

scholarly journals Endogeic earthworms shape bacterial functional communities and affect organic matter mineralization in a tropical soil

2011 ◽  
Vol 6 (1) ◽  
pp. 213-222 ◽  
Author(s):  
Laetitia Bernard ◽  
Lydie Chapuis-Lardy ◽  
Tantely Razafimbelo ◽  
Malalatiana Razafindrakoto ◽  
Anne-Laure Pablo ◽  
...  
Keyword(s):  
Organic Matter ◽  
Tropical Soil ◽  
Organic Matter Mineralization ◽  
Endogeic Earthworms

scholarly journals Potassium Control of Plant Functions: Ecological and Agricultural Implications

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 419
Author(s):  
Jordi Sardans ◽  
Josep Peñuelas
Keyword(s):  
Food Security ◽  
Stress Responses ◽  
Crop Production ◽  
Terrestrial Ecosystem ◽  
Terrestrial Ecosystems ◽  
Wood Formation ◽  
Cellular Growth ◽  
Ecosystem Functions ◽  
Metabolite Transport ◽  
Physiological Functions

Potassium, mostly as a cation (K+), together with calcium (Ca2+) are the most abundant inorganic chemicals in plant cellular media, but they are rarely discussed. K+ is not a component of molecular or macromolecular plant structures, thus it is more difficult to link it to concrete metabolic pathways than nitrogen or phosphorus. Over the last two decades, many studies have reported on the role of K+ in several physiological functions, including controlling cellular growth and wood formation, xylem–phloem water content and movement, nutrient and metabolite transport, and stress responses. In this paper, we present an overview of contemporary findings associating K+ with various plant functions, emphasizing plant-mediated responses to environmental abiotic and biotic shifts and stresses by controlling transmembrane potentials and water, nutrient, and metabolite transport. These essential roles of K+ account for its high concentrations in the most active plant organs, such as leaves, and are consistent with the increasing number of ecological and agricultural studies that report K+ as a key element in the function and structure of terrestrial ecosystems, crop production, and global food security. We synthesized these roles from an integrated perspective, considering the metabolic and physiological functions of individual plants and their complex roles in terrestrial ecosystem functions and food security within the current context of ongoing global change. Thus, we provide a bridge between studies of K+ at the plant and ecological levels to ultimately claim that K+ should be considered at least at a level similar to N and P in terrestrial ecological studies.

scholarly journals Linking Genes to Traits in Fungi

2021 ◽  
Author(s):  
A. L. Romero-Olivares ◽  
E. W. Morrison ◽  
A. Pringle ◽  
S. D. Frey
Keyword(s):  
Organic Matter ◽  
Nitrogen Uptake ◽  
Brown Rot ◽  
Terrestrial Ecosystems ◽  
Organic Matter Decomposition ◽  
Gene Frequencies ◽  
Ecological Processes ◽  
Linked Gene ◽  
Carbon Cycles ◽  
Brown Rot Fungi

AbstractFungi are mediators of the nitrogen and carbon cycles in terrestrial ecosystems. Examining how nitrogen uptake and organic matter decomposition potential differs in fungi can provide insight into the underlying mechanisms driving fungal ecological processes and ecosystem functioning. In this study, we assessed the frequency of genes encoding for specific enzymes that facilitate nitrogen uptake and organic matter decomposition in 879 fungal genomes with fungal taxa grouped into trait-based categories. Our linked gene-trait data approach revealed that gene frequencies vary across and within trait-based groups and that trait-based categories differ in trait space. We present two examples of how this linked gene-trait approach can be used to address ecological questions. First, we show that this type of approach can help us better understand, and potentially predict, how fungi will respond to environmental stress. Specifically, we found that trait-based categories with high nitrogen uptake gene frequency increased in relative abundance when exposed to high soil nitrogen enrichment. Second, by comparing frequencies of nitrogen uptake and organic matter decomposition genes, we found that most ectomycorrhizal fungi in our dataset have similar gene frequencies to brown rot fungi. This demonstrates that gene-trait data approaches can shed light on potential evolutionary trajectories of life history traits in fungi. We present a framework for exploring nitrogen uptake and organic matter decomposition gene frequencies in fungal trait-based groups and provide two concise examples on how to use our framework to address ecological questions from a mechanistic perspective.

scholarly journals Coastal hypoxia and sediment biogeochemistry

2009 ◽  
Vol 6 (7) ◽  
pp. 1273-1293 ◽  
Author(s):  
J. J. Middelburg ◽  
L. A. Levin
Keyword(s):  
Organic Matter ◽  
Bottom Water ◽  
Water Exchange ◽  
Transport Processes ◽  
Ecosystem Dynamics ◽  
Ecosystem Functions ◽  
Oxygen Levels ◽  
Concise Review ◽  
Water Oxygen ◽  
Sediment Biogeochemistry

Abstract. The intensity, duration and frequency of coastal hypoxia (oxygen concentration <63 μM) are increasing due to human alteration of coastal ecosystems and changes in oceanographic conditions due to global warming. Here we provide a concise review of the consequences of coastal hypoxia for sediment biogeochemistry. Changes in bottom-water oxygen levels have consequences for early diagenetic pathways (more anaerobic at expense of aerobic pathways), the efficiency of re-oxidation of reduced metabolites and the nature, direction and magnitude of sediment-water exchange fluxes. Hypoxia may also lead to more organic matter accumulation and burial and the organic matter eventually buried is also of higher quality, i.e. less degraded. Bottom-water oxygen levels also affect the organisms involved in organic matter processing with the contribution of metazoans decreasing as oxygen levels drop. Hypoxia has a significant effect on benthic animals with the consequences that ecosystem functions related to macrofauna such as bio-irrigation and bioturbation are significantly affected by hypoxia as well. Since many microbes and microbial-mediated biogeochemical processes depend on animal-induced transport processes (e.g. re-oxidation of particulate reduced sulphur and denitrification), there are indirect hypoxia effects on biogeochemistry via the benthos. Severe long-lasting hypoxia and anoxia may result in the accumulation of reduced compounds in sediments and elimination of macrobenthic communities with the consequences that biogeochemical properties during trajectories of decreasing and increasing oxygen may be different (hysteresis) with consequences for coastal ecosystem dynamics.

scholarly journals Soil Pollution vs. Soil Collembola as a Bioindicator: A review

2010 ◽  
Vol 2 (5) ◽  
pp. 1-11
Author(s):  
Atreyee Sahana
Keyword(s):  
Organic Matter ◽  
Soil Health ◽  
Soil Formation ◽  
Terrestrial Ecosystems ◽  
Soil Types ◽  
Natural Soil ◽  
Natural Health ◽  
Arthropod Fauna ◽  
Mineral Components ◽  
Inorganic Mineral

Soil is the foundation of all life activities in terrestrial ecosystems. Soil micro arthropod groups (less than 2 mm in size) like Acari and Collembola comprise more than 90% of arthropod fauna in most soil types. They majorly help in soil formation by breaking up the organic matter and mixing it up with inorganic mineral components. Among them, various species of Collembola have been proved to be effective bioindicator tool to measure soil health either it is polluted or not by its several characteristics in temperate countries. Therefore, in today’s world where pollution in soil by various agents is a baffling issue like other environmental pollutions, these natural soil inhabitants can make a hope to measure the natural health of soil.

scholarly journals Type of organic fertilizer rather than organic amendment per se increases abundance of soil biota

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11204
Author(s):  
Maria Viketoft ◽  
Laura G.A. Riggi ◽  
Riccardo Bommarco ◽  
Sara Hallin ◽  
Astrid R. Taylor
Keyword(s):  
Organic Matter ◽  
Organic Amendments ◽  
Trophic Levels ◽  
Soil Biota ◽  
Organic Fertilizers ◽  
Nitrogen Fertilizers ◽  
Mineral Fertilizers ◽  
Soil Organisms ◽  
Wide Range

Addition of organic amendments is a commonly used practice to offset potential loss of soil organic matter from agricultural soils. The aim of the present study was to examine how long-term addition of organic matter affects the abundance of different soil biota across trophic levels and the role that the quality of the organic amendments plays. Here we used a 17-year-old fertilization experiment to investigate soil biota responses to four different organic fertilizers, compared with two mineral nitrogen fertilizers and no fertilization, where the organic fertilizers had similar carbon content but varied in their carbon to nitrogen ratios. We collected soil samples and measured a wide range of organisms belonging to different functional groups and trophic levels of the soil food web. Long-term addition of organic and mineral fertilizers had beneficial effects on the abundances of most soil organisms compared with unfertilized soil, but the responses differed between soil biota. The organic fertilizers generally enhanced bacteria and earthworms. Fungi and nematodes responded positively to certain mineral and organic fertilizers, indicating that multiple factors influenced by the fertilization may affect these heterogeneous groups. Springtails and mites were less affected by fertilization than the other groups, as they were present at relatively high abundances even in the unfertilized treatment. However, soil pH had a great influence on springtail abundance. In summary, the specific fertilizer was more important in determining the numerical and compositional responses of soil biota than whether it was mineral or organic. Overall, biennial organic amendments emerge as insufficient, by themselves, to promote soil organisms in the long run, and would need to be added annually or combined with other practices affecting soil quality, such as no or reduced tillage and other crop rotations, to have a beneficial effect.

scholarly journals Compositional and chemical characteristics of dissolved organic matter in various types of cropped and natural Chinese soils

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Songyan Li ◽  
Meng Li ◽  
Guoxi Wang ◽  
Xiaolei Sun ◽  
Beidou Xi ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Soil Type ◽  
Spectral Characteristics ◽  
Terrestrial Ecosystems ◽  
Soil Types ◽  
Chemical Characteristics ◽  
Natural Soils ◽  
Red Soils ◽  
Chernozem Soils

Abstract Background Exploration of composition and chemical characteristics of soil dissolved organic matter (DOM) is significant to understand its biogeochemical role in terrestrial ecosystems. A total of 43 cropped and 16 natural soils (0–20 cm) under four soil types (cinnamon, chernozem, red and paddy soils) across China were collected to investigate the spectral characteristics of DOM using UV–Vis and 3D-EEM spectroscopy. Results The chernozem soils exhibited the highest aromaticity and humification degree among the four soil types. Ranges of biological index (BIX, 0.53–1.17) and fluorescence index (FI, 1.55–2.10) were found in the investigated DOM, showing joint contribution from allochthonous and autochthonous sources. Higher BIX and FI in the DOM of the paddy and red soils indicated a greater reliance on autochthonous sources for these two soil types. The cropped soils showed no significant differences in chemical characteristics and sources from the natural soils for the cinnamon, chernozem and red soils. UVA (16.2–47.9%) and UVC fulvic-like substances (15.4–40.5%) were the prevailing DOM components, which were highest in the chernozem soils. Additionally, the cropped soils had a higher proportion of humic-like substances than the natural soils in the DOM. Conclusions Both soil type and land-use strongly affected the chemical characteristics of soil DOM, but only soil type had an impact on the DOM composition for the collected soils. These findings may contribute to the prediction of the biochemical behavior of soil DOM under different soil types and land-uses in terrestrial ecosystems.

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