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Soil aggregation has received a lot of attention in the last years; however, the focus was mostly on soil microorganisms or larger soil fauna, especially earthworms. The impact of the large group of microarthropods, e.g. Collembola and Acari, is nearly unknown and hence underrepresented in the literature. Here we propose and discuss potential direct and indirect mechanisms of how microarthropods could influence this process with the focus on collembolans, which are in general a relatively well studied taxon. Indirect mechanisms are likely to have larger impacts on soil aggregation than direct effects. The variety of indirect mechanisms based on the provision of organic material like fecal pellets, molts and necromass as food source for microorganisms is high and given available evidence we propose that these mechanisms are the most influential. We highlight the need for overcoming the challenges of culturing and handling of these animals in order to be able to design small scale experiments and field studies which would enable us to understand the role of the different functional groups, their interaction with other soil fauna and the impact of land use practices on soil aggregation. [ABSTRACT FROM AUTHOR]

• Both Mesostigmata adult and juvenile abundance increased under warming. • Mesostigmata assemblages shifted and average individual body mass increased. • Assemblages shifted due to the increased abundances of parthenogenetic species. • These results align with previous studies on Oribatida assemblages under warming. Increasing global mean surface temperatures from climate change will coincide with longer and more frequent short-term, extreme warming events. Because of this, habitats like boreal forests are predicted to have new temperature regimes. Boreal forest soils contain a diverse array of microarthropods and nematodes, which include the main soil predators, mesostigmatic mites (Acari: Parasitiformes: Mesostigmata). Although extensive research exists on how climate warming affects oribatid mite and collembolan communities, fewer studies have examined how warming effects Mesostigmata communities. We tested the effect of short-term (three months), intensive warming (+8 °C) on Mesostigmata communities from the boreal forest using experimental mesocosms containing forest-floor material. We collected moss mats and underlying forest floor organic material from a boreal forest and incubated them within individual mesocosms at 12 °C and 20 °C for three months, where 12 °C represented the long-term average growing season temperature and 20 °C corresponds to the potential extreme surface temperature from climate warming for the region. We enumerated all extracted microarthropods and nematodes, and identified all Mesostigmata adults to the species-level. In total, we counted 24,080 nematode individuals, and 19,582 total microarthropod individuals, of which 3349 individuals (1899 adults and 1450 juveniles) were mesostigmatic mites, consisting of 14 species. Mesostigmatic juvenile and adult abundances, along with adult community-level body mass were higher under warming, which lead to a shift in community composition. Changes to Mesostigmata communities were driven by the greater abundances of parthenogenetic species, primarily Veigaia mitis (Berlese), under warming—a response that has been shown in oribatid mite communities, but not mesostigmatic communities, before. Overall, we found that warming shifted mesostigmatic mite communities in the boreal forest, which has wide ranging implications for the soil food web. [ABSTRACT FROM AUTHOR]

There is an increasing interest in understanding how soil microbial communities respond to perturbations associated with global change. Much of the currently available knowledge is based on controlled laboratory experiments, large scale surveys and manipulative studies in which one perturbation, for example drought, is applied under a range of conditions. Until now, emphasis has been on spatial replication of experimental units and the quantification of variation in soil microbial community structure, and its correlation to ecosystem-level variables such as gas fluxes. But microbial communities naturally fluctuate over time, their response to perturbations is temporal, and they generally experience multiple perturbations simultaneously and/or in a variable sequence, such as spells of drought alternating with flooding events. Furthermore, variation in the soil microbial community in response to perturbations may not directly reflect the overall expression of functions of a microbial community. Here, we identify three experimental challenges that we refer to as the variance , locality and structure challenge. We briefly synthesise the state of the art around these three challenges to open a discussion on the many experimental issues ecologists face when measuring the effects of perturbations on the structure and functions of soil microbial communities in time and space. We propose experimental, sampling and modelling strategies that can help resolve the experimental challenges discussed in this paper. [ABSTRACT FROM AUTHOR]

Summary: Clay pigeon shooting ranges can be an important source of heavy metal contamination in terrestrial ecosystems. The pellets contained in spent ammunition are mainly composed of lead (Pb) and antimony (Sb). Total concentrations of these metals were measured in soils from seven sampling sites within a clay pigeon shooting range and compared with two controls to investigate the effects of their increased levels on the oribatid mites and Collembola community. We found that the spatial distribution of Pb and Sb contamination in the fall-out area is strongly related to the flight path of pellets. Oribatid and Collembola communities are able to survive at levels of heavy metals far higher than the lethal concentration for the most tolerant plants but oribatid mites seem to be affected by heavy metals more than springtails. Collembola and oribatid mites exhibit a wide range of responses to disturbance and many species are more strongly influenced by microhabitat characteristics than levels of pollution. The effects of annual cultivations conducted in the shooting range and those of heavy metal pollution result in a simplification and homogeneity of community composition. Among arthropods, oribatid mites and springtails have a great potential as bioindicators of environmental conditions; the issue remains as to whether differences in population structure can be used to determine the type of disturbance. [Copyright &y& Elsevier]

The ecological interactions that occur in and with soil are of consequence in many ecosystems on the planet. These interactions provide numerous essential ecosystem services, and the sustainable management of soils has attracted increasing scientific and public attention. Although soil ecology emerged as an independent field of research many decades ago, and we have gained important insights into the functioning of soils, there still are fundamental aspects that need to be better understood to ensure that the ecosystem services that soils provide are not lost and that soils can be used in a sustainable way. In this perspectives paper, we highlight some of the major knowledge gaps that should be prioritized in soil ecological research. These research priorities were compiled based on an online survey of 32 editors of Pedobiologia – Journal of Soil Ecology. These editors work at universities and research centers in Europe, North America, Asia, and Australia. The questions were categorized into four themes: (1) soil biodiversity and biogeography, (2) interactions and the functioning of ecosystems, (3) global change and soil management, and (4) new directions. The respondents identified priorities that may be achievable in the near future, as well as several that are currently achievable but remain open. While some of the identified barriers to progress were technological in nature, many respondents cited a need for substantial leadership and goodwill among members of the soil ecology research community, including the need for multi-institutional partnerships, and had substantial concerns regarding the loss of taxonomic expertise. [ABSTRACT FROM AUTHOR]

Community coalescence is a recently introduced term describing the interaction of entire communities and their environments. We here explicitly place the concept of community coalescence in a soil microbial context, exploring intrinsic and extrinsic drivers of such coalescence events. Examples of intrinsic events include the action of earthworms and the dynamics of soil aggregates, while extrinsic events are exemplified by tillage, flooding, litter-fall, outplanting, and the addition of materials containing microbial communities. Aspects of global change may alter the frequency or severity of coalescence events. We highlight functional consequences of community coalescence in soil, and suggest ways to experimentally tackle this phenomenon. Soil ecology as a whole stands to benefit from conceptualizing soil biodiversity in terms of dynamic coalescent microbial assemblages. [ABSTRACT FROM AUTHOR]