Networks of power and influence: the role of mycorrhizal mycelium in controlling plant communities and agroecosystem functioning

2004 ◽  
Vol 82 (8) ◽  
pp. 1016-1045 ◽  
Author(s):  
Jonathan Leake ◽  
David Johnson ◽  
Damian Donnelly ◽  
Gemma Muckle ◽  
Lynne Boddy ◽  
...  
Keyword(s):  
Plant Communities ◽  
Mycorrhizal Fungi ◽  
Host Plants ◽  
Soil Microbial Biomass ◽  
Ecosystem Processes ◽  
Nutrient Fluxes ◽  
Potential Contribution ◽  
Soil Microbial ◽  
Functionally Diverse

Extraradical mycelia of mycorrhizal fungi are normally the “hidden half” of the symbiosis, but they are powerful underground influences upon biogeochemical cycling, the composition of plant communities, and agroecosystem functioning. Mycorrhizal mycelial networks are the most dynamic and functionally diverse components of the symbiosis, and recent estimates suggest they are empowered by receiving as much as 10% or more of the net photosynthate of their host plants. They often constitute 20%–30% of total soil microbial biomass yet are undetected by standard measures of biomass used by soil scientists and agromomists. Mycorrhizal mycelia provide extensive pathways for carbon and nutrient fluxes through soil, often exceeding tens of metres per gram of soil. We consider the amounts of photosynthate “power” allocated to these mycelial networks and how this is used in fungal respiration, biomass, and growth and in influencing soil, plant, and ecosystem processes. The costs and functional “benefits” to plants linking to these networks are fungal specific and, because of variations in physiology and host specificity, are not shared equally; some plants even depend exclusively on these networks for carbon. We briefly assess the potential contribution of extraradical mycorrhizal mycelium to sustainable agriculture and maintenance of biodiversity and highlight technologies that promise new vistas and improved fine-scale resolution of the dynamic spatial and temporal functioning of these networks in soil.Key words: arbuscular mycorrhiza, ectomycorrhiza, extraradical mycelium, hyphal networks.

scholarly journals Mycorrhizal Fungi as Bioprotectors of Crops Against Verticillium Wilt—A Hypothetical Scenario Under Changing Environmental Conditions

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1468
Author(s):  
Nieves Goicoechea
Keyword(s):  
Environmental Factors ◽  
Mycorrhizal Fungi ◽  
Host Plants ◽  
Current Knowledge ◽  
Water Status ◽  
Arbuscular Mycorrhizal ◽  
Hypothetical Scenario ◽  
Soil Temperatures ◽  
Amf Communities

The association that many crops can establish with the arbuscular mycorrhizal fungi (AMF) present in soils can enhance the resistance of the host plants against several pathogens, including Verticillium spp. The increased resistance of mycorrhizal plants is mainly due to the improved nutritional and water status of crops and to enhanced antioxidant metabolism and/or increased production of secondary metabolites in the plant tissues. However, the effectiveness of AMF in protecting their host plants against Verticillium spp. may vary depending on the environmental factors. Some environmental factors, such as the concentration of carbon dioxide in the atmosphere, the availability of soil water and the air and soil temperatures, are predicted to change drastically by the end of the century. The present paper discusses to what extent the climate change may influence the role of AMF in protecting crops against Verticillium-induced wilt, taking into account the current knowledge about the direct and indirect effects that the changing environment can exert on AMF communities in soils and on the symbiosis between crops and AMF, as well as on the development, incidence and impact of diseases caused by soil-borne pathogens.

A meta-analysis of soil microbial biomass levels from established tree plantations over various land uses, climates and plant communities

CATENA ◽  
2017 ◽  
Vol 150 ◽  
pp. 256-260 ◽  
Author(s):  
Qian Zhang ◽  
Junjie Yang ◽  
Roger T. Koide ◽  
Tao Li ◽  
Haishui Yang ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Plant Communities ◽  
Soil Microbial Biomass ◽  
Meta Analysis ◽  
Tree Plantations ◽  
Land Uses ◽  
Soil Microbial

Native prairie grasses and microbial community responses to reclamation of taconite iron ore tailing

1995 ◽  
Vol 73 (10) ◽  
pp. 1645-1654 ◽  
Author(s):  
Robert K. Noyd ◽  
F. L. Pfleger ◽  
Michael R. Norland ◽  
Michael J. Sadowsky
Keyword(s):  
Microbial Biomass ◽  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Soil Microbial Biomass ◽  
Plant Cover ◽  
Arbuscular Mycorrhizal ◽  
Yard Waste ◽  
Soil Microbial ◽  
Native Prairie ◽  
Prairie Grasses

The effect of reclamation treatments on seeded native grass cover and species composition, soil microbial biomass carbon, and populations of actinomycetes, fungi, free-living N2-fixing bacteria, and aerobic heterotrophic bacteria was compared in field plots in coarse taconite tailing. Reclamation treatments consisted of all possible combinations of three rates of composed yard waste, three rates of fertilizer, and inoculation with arbuscular mycorrhizal fungi. Composted yard waste increased plant cover, soil microbial biomass, and populations of all groups of microorganisms compared with unamended, non-inoculated control plots. Microbial populations and biomass in tailing plots were low compared with natural soils and were correlated with plant cover and available P. Mycorrhizal inoculation resulted in a 6% increase in plant cover, although this was not significant, and significantly enhanced N2-fixer populations in June but did not affect other groups of microorganisms. There were no differences between moderate and high rates of composted yard waste. We conclude that incorporation of a moderate rate of organic matter can ameliorate the stressful conditions of coarse taconite tailing and can enhance the initiation of a functional soil ecosystem able to support the establishment of seeded native prairie grasses and may provide a long-term solution to reclamation of taconite tailing. Key words: arbuscular mycorrhizal fungi, mine reclamation, soil microorganisms, composted yard waste.

scholarly journals Nutrient Source and Mycorrhizal Association jointly alters Soil Microbial Communities that shape Plant-Rhizosphere-Soil Carbon-Nutrient Flows

2020 ◽  
Author(s):  
Somak Chowdhury ◽  
Markus Lange ◽  
Ashish A Malik ◽  
Timothy Goodall ◽  
Jianbei Huang ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Litter Decomposition ◽  
Plant Communities ◽  
Soil Microbial Communities ◽  
Ecosystem Processes ◽  
Carbon Flow ◽  
Simultaneous Increase ◽  
Soil Microbial ◽  
Mycorrhizal Association ◽  
C Assimilation

AbstractInteractions between plants and microorganisms strongly affect ecosystem functioning as processes of plant productivity, litter decomposition and nutrient cycling are controlled by both organisms. Though two-sided interactions between plants and microorganisms and between microorganisms and litter decomposition are areas of major scientific research, our understanding of the three-sided interactions of plant-derived carbon flow into the soil microbial community and their follow-on effects on ecosystem processes like litter decomposition and plant nutrient uptake remains limited. Therefore, we performed a greenhouse experiment with two plant communities differing in their ability to associate with arbuscular mycorrhizal fungi (AMF). By applying a 13CO2 pulse label to the plant communities and adding various 15N labelled substrate types to ingrowth cores, we simultaneously traced the flow of plant-derived carbon into soil microbial communities and the return of mineralized nitrogen back to the plant communities. We observed that net 13C assimilation by the rhizosphere microbial communities and their community composition not only depended on plant-AMF association but also type of substrate being decomposed. AMF-association resulted in lower net 13C investment into the decomposer community than absence of the association for similar 15N uptake. This effect was driven by a reduced carbon flow to fungal and bacterial saprotrophs and a simultaneous increase of carbon flow to AMF. Additionally, in presence of AMF association CN flux also depended on the type of substrate being decomposed. Lower net 13C assimilation was observed for decomposition of plant-derived and microorganism-derived substrates whereas opposite was true for inorganic nitrogen. Interestingly, the decomposer communities assembled in the rhizosphere were structured by both the plant community and substrate amendments which suggests existence of functional overlap between the two soil contexts. Moreover, we present preliminary evidence that AMF association helps plants access nutrients that are locked in bacterial and plant necromass at a lower carbon cost. Therefore, we conclude that a better understanding of ecosystem processes like decomposition can only be achieved when the whole plant-microorganism-litter context is investigated.

scholarly journals David Stewart Jenkinson. 25 February 1928 — 16 February 2011

2017 ◽  
Vol 63 ◽  
pp. 377-411
Author(s):  
David Powlson ◽  
Phil Brookes
Keyword(s):  
Organic Matter ◽  
Microbial Biomass ◽  
Organic Carbon ◽  
Nitrogen Fertilizer ◽  
Management Practices ◽  
Soil Microbial Biomass ◽  
Soil Microbial ◽  
Long Term Experiments

David Jenkinson was one of the most influential soil scientists of his generation, bringing new insights into the transformations of organic matter and nitrogen in soil. He spent the majority of his career at Rothamsted Research, Harpenden, UK. His studies were influential regarding the role of soil carbon stocks in the context of climate change and the role of nitrogen fertilizer in delivering adequate supplies of food for a growing world population. His research encompassed both fundamental studies on soil processes and immensely practical applications of this knowledge, often utilizing the Rothamsted long-term experiments that have run for over 170 years. He is particularly well known for his development of a method for determining the quantity of organic carbon held in the cells of living micro-organisms in soil, termed the ‘soil microbial biomass’. This breakthrough opened the way for a new wave of soil biological research. David developed one of the earliest computer models for the turnover of organic carbon in soil, known as the Rothamsted Carbon Model, RothC. This model, conceptually very simple, has proved highly successful in simulating and predicting changes in soil organic carbon (SOC) content under different management practices worldwide, being used by over 2600 people in 115 countries. His research using the stable isotope of nitrogen, 15 N, in large-scale field experiments drew attention to the factors leading to inefficiencies in the use of nitrogen fertilizer but also demonstrated that it is possible to achieve high efficiency if good agricultural management practices are followed. It also demonstrated, more clearly than previously, the great importance of soil organic matter as a source of nitrogen for crops and the role of the soil microbial biomass both in immobilizing a proportion of applied fertilizer nitrogen and also in causing confusion in the interpretation of such experiments. By calculating nitrogen budgets for the Rothamsted long-term experiments he quantified the deposition of nitrogen compounds from atmosphere to land, laying foundations for later studies concerning the ecological and agricultural impacts of this significant input of nitrogen.

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