Strain identity of the ectomycorrhizal fungus Laccaria bicolor is more important than richness in regulating plant and fungal performance under nutrient rich conditions

This work was funded by the Natural Environment Research Council (NE/I014527/1).Peer reviewedPublisher PD

Variation in carbon and nitrogen concentrations among peatland categories at the global scale

Publisher Copyright: © 2022 This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.Peatlands account for 15 to 30% of the world's soil carbon (C) stock and are important controls over global nitrogen (N) cycles. However, C and N concentrations are known to vary among peatlands contributing to the uncertainty of global C inventories, but there are few global studies that relate peatland classification to peat chemistry. We analyzed 436 peat cores sampled in 24 countries across six continents and measured C, N, and organic matter (OM) content at three depths down to 70 cm. Sites were distinguished between northern (387) and tropical (49) peatlands and assigned to one of six distinct broadly recognized peatland categories that vary primarily along a pH gradient. Peat C and N concentrations, OM content, and C:N ratios differed significantly among peatland categories, but few differences in chemistry with depth were found within each category. Across all peatlands C and N concentrations in the 10-20 cm layer, were 440 ± 85.1 g kg-1 and 13.9 ± 7.4 g kg-1, with an average C:N ratio of 30.1 ± 20.8. Among peatland categories, median C concentrations were highest in bogs, poor fens and tropical swamps (446-532 g kg-1) and lowest in intermediate and extremely rich fens (375-414 g kg-1). The C:OM ratio in peat was similar across most peatland categories, except in deeper samples from ombrotrophic tropical peat swamps that were higher than other peatlands categories. Peat N concentrations and C:N ratios varied approximately two-fold among peatland categories and N concentrations tended to be higher (and C:N lower) in intermediate fens compared with other peatland types. This study reports on a unique data set and demonstrates that differences in peat C and OM concentrations among broadly classified peatland categories are predictable, which can aid future studies that use land cover assessments to refine global peatland C and N stocks.Peer reviewe

Genotypic Diversity Matters: Examining the diversity-ecosystem function relationship with ectomycorrhizal fungi

International audienc

Use and abuse of potential rates in soil microbiology

Potential rate assays are used in soil microbial ecology to determine the maximum rate of a functional process in environmental samples. They assume that all contributing organisms in a community are active at a maximum rate under one set of ‘optimal’ incubation conditions. Potential rates are then often compared to the abundance of specific taxonomic groups to infer their relative contribution in situ . However, while investigators now recognise that populations within communities are physiologically diverse, they often ignore the consequent suboptimal activity, or even inactivity, of the majority of community members performing that function. In this short perspective article, we highlight the underlying conceptual problems associated with potential assays and use potential nitrification rate (PNR) as an example. PNR was originally developed to estimate the size of active ammonia oxidising communities in environmental samples. They are routinely performed in short-term shaken slurry incubations by measuring assumed maximum rates of nitrate or nitrite production under optimal, non-substrate-limiting conditions. As with other functional processes, it is now recognised that a broad diversity of organisms contribute to aerobic ammonia oxidation in terrestrial and other habitats, and this diversity represents a substantial range of physiologies, including variation in substrate affinity, ammonia tolerance, cell specific activity and substrate preference. Despite this, PNR is routinely used in an attempt to determine an ecologically relevant measurement of nitrification activity in soil. As with other potential assays, PNR has inherent biases towards particular functional groups and its use in investigating the ecology of ammonia oxidisers in natural systems is severely restricted

Importance of intraspecific diversity of ectomycorrhizal fungi for regulating ecosystem functioning

International audienc

Genotypic Diversity Matters: Examining the diversity-ecosystem function relationship with ectomycorrhizal fungi

International audienc

Distance Learning Practices in Military Training and Education

21st Annual Conference on Distance Teaching and Learnin

Uncovering virus-bacterial host interactions across ecological gradients in soil

International audienc

Uncovering virus-bacterial host interactions across ecological gradients in soil

International audienc

Application of organic residues on soils with contrasting nitrogen fertilization differentially impacts the diversity of soil microbial communities

International audienc