Oribatid mite and collembolan diversity, density and community structure in a moder beech forest (Fagus sylvatica): effects of mechanical perturbations

The effects of mechanical perturbations on two soil microarthropod communities (oribatid mites and collembolans) were investigated in a moder beech forest on sandstone. We disturbed the soil matrix by sieving and mixing the litter and soil of the moder profile. The top litter layer (L material) and the deep mineral soil (Bv) remained intact. Three amounts of disturbance were established: a single perturbation, perturbations once every 2 months (60 d) and once every 2 weeks (14 d). Densities of most groups of oribatid mites and all groups of collembolans declined in the disturbance treatments. In most cases, densities were lowest in the strong perturbation treatment (14 d). Desmonomata were the only group of oribatid mites that benefited from intermediate amounts of disturbance but not from the strongest disturbance. Also, disturbances reduced diversity of oribatid mites and collembolans. According to their sensitivity to disturbances oribatid mites ranked Poronota=Enarthronota=Suctobelbidae (the most sensitive)>Oppiidae>Tectocepheus>Desmonomata. The ranking of collembolans was Folsomia (the most sensitive)>Hypogastruridae/Neanuridae>Onychiuridae=Isotomidae>Entomobryidae. Generally, tolerance of disturbance was wider for oribatid mites than for collembolans. The results indicate that disturbances such as mixing of litter and soil and comminution of litter material strongly affect the density and diversity of soil microarthropods. However, they also indicate that the soil microarthropod community is resistant to weaker disturbances. In the field, mechanical disturbances are often caused by burrowing of earthworms. Our results suggest that the high density of microarthropods in moder soils may be due to the low intensities of mechanical disturbances by earthworms.     

A comparison of microarthropod assemblages with emphasis on oribatid mites in canopy suspended soils and forest floors associated with ancient western redcedar trees

Microarthropod abundance, oribatid mite species richness and community composition were assessed in the high canopy (ca. 35 m) of an ancient temperate rainforest and compared with microarthropod communities of the forest floor. Microarthropods were extracted from 72 core samples of suspended soils and 72 core samples from forest floors associated with six western redcedar trees in the Walbran Valley on the southwest coast of Vancouver Island, Canada. Total microarthropod abundances, mesostigmatid and astigmatid mites, Collembola and other microarthropod abundances were significantly greater in forest floors compared to canopy habitats. Oribatid and prostigmatid mite abundance were not significantly different between habitats. The relative abundances of all microarthropod groups considered in this study differed significantly between habitats. Eighty-eight species of oribatid mites were identified from the study area. Eighteen of the 53 species observed in suspended soils were unique to the canopy. Cluster analysis indicates that the arboreal oribatid mite community is distinct and not a taxonomic subset of the forest floor assemblage, however, canopy oribatid mite communities are more heterogeneous in species composition than in the forest floor.     

Responses of soil microarthropods to changes in soil water availability in tallgrass prairie

 Changes in precipitation and soil water availability predicted to accompany global climate change would impact grasslands, where many ecosystem processes are influenced by water availability. Soil biota, including microarthropods, also are affected by soil water content, although little is known about how climate change might affect their abundance and distribution. The goal of this study was to examine soil microarthropod responses to altered soil water availability in tallgrass prairie ecosystems. Two separate experiments were done. The first utilized control and irrigated plots along a topographic gradient to examine the effects of soil water content on microarthropod densities. Microarthropods, mainly Acari, were significantly less abundant in irrigated plots and were generally less abundant at the wetter lowland sites. The second study utilized reciprocal core transplants across an east-west regional precipitation gradient. Large, intact cores were transplanted between a more mesic tallgrass site (Konza Prairie) and a more arid mixed-grass site (Hays) to determine the effects of different soil water regimes on microarthropod abundance and vertical distribution. Data from non-transplanted cores indicated greater total microarthropod densities at the drier Hays site, relative to the wetter Konza Prairie site. Data from the transplanted cores indicated significant effects of location on Acari densities in cores originating from Hays, with higher densities in cores remaining at Hays, relative to those transplanted to Konza. Acari densities in cores originating from Konza were not affected by location; however, oribatid mite densities generally were greater in cores remaining at Konza Prairie. These results confirm the importance of soil water content in affecting microarthropod densities and distributions in grasslands, and suggest complex, non-linear responses to changes in water availability. Received: 14 April 1998     

Soil fauna abundance and diversity in a secondary semi-evergreen forest in Guadeloupe (Lesser Antilles): influence of soil type and dominant tree species

The importance of secondary tropical forests regarding the maintenance of soil fauna abundance and diversity is poorly known. The aims of this study were (1) to describe soil fauna abundance and diversity and (2) to assess the determinants of soil fauna abundance and diversity in two stands of a tropical semi-evergreen secondary forest. Soil macrofauna and microarthropod abundance and soil macrofauna diversity were described at two sites developed on different soils and with different site histories: (1) a natural secondary stand (natural forest) under two dominant tree species, Pisonia subcordata and Bursera simaruba, and (2) a planted secondary forest (planted forest) under three tree species, B. simaruba, Swietenia macrophylla, and Tabebuia heterophylla. The effects of both soil and main tree species’ litter quality were assessed to explain soil fauna abundance and diversity. The abundance of soil macrofauna was significantly higher in the soil under the planted forest, and soil fauna communities were contrasted between the two sites. In the planted forest, a soil-dwelling macrofauna community developed (mainly consisting of the anecic earthworm Polypheretima elongata). In the natural forest, soil macrofauna and microarthropod communities were located at the soil surface. The effect of plant litter quality varied according to each dominant tree species and was superimposed to soil effect. The lowest macrofauna abundance was associated with B. simaruba in the natural forest. T. heterophylla supported a much greater macrofauna community than the two other tree species studied at the same soil, and it appears likely that this is due to the palatability of its leaves compared with the other trees (low lignin, tannins, soluble phenols).     

Landscape variation in microarthropod response to calcium addition in a northern hardwood forest ecosystem

Loss of base cations from soils of the northeastern US may adversely influence forest health. A watershed-level calcium (as wollastonite, CaSiO₃) addition experiment was initiated at the Hubbard Brook Experimental Forest, NH, USA, in fall 1999 to examine responses of forest ecosystem structure and function to restoration of exchangeable Ca that was lost over previous decades. We quantified the response of soil microarthropods to Ca addition as part of this larger study, and we also quantified microarthropod response to smaller scale (1×2 m plots) wollastonite additions within one site in an untreated reference watershed. We observed a small increase in pH in the surface organic horizon, accompanied by a decline in microarthropod abundance per gram organic matter three years following wollastonite application. However, responses varied among microarthropod groups, across years, and among study plots that were distributed along an elevation gradient in treatment and reference watersheds. Collembola declined in the treatment relative to the reference watershed in the second year but recovered in the third year following wollastonite application, whereas oribatid, prostigmatid, and mesostigmatid mites all declined in the treatment relative to the reference watershed by the third year following treatment. The largest treatment responses were observed in two base-poor hardwood stands, whereas at a slightly less poor hardwood site we found the least abundant and least variable microarthropod populations, and no response was observed to either the watershed or the plot-level treatments. Our results demonstrate that soil microarthropods are sensitive to relatively small changes in soil Ca, but that landscape position must be considered in testing responses of these soil biota to soil base status.     

Effects of microhabitat diversity and geographical isolation on oribatid mite (Acari: Oribatida) communities in mangrove forests

The effects of microhabitat diversity and geographical isolation on the structure of oribatid communities were studied in mangrove forests on the Ryukyu Islands of Japan. The study took place at three sites on two islands 470 km apart. Oribatid mites (Oribatida) were extracted from leaves, branches, bark of trunks (0-50, 50-100, and 100-150 cm high) and of knee roots, and from forest-floor soil and littoral algae, each defined as a microhabitat of oribatid mites. At the 0-50 cm height, the species composition of the oribatid communities on the knee-root bark and the bark of trunks of Bruguiera gymnorrhiza differed significantly from that on the other microhabitats. This difference was attributed to tidal flooding of the mangrove forests. Cluster analysis showed that oribatid communities in the same microhabitat at different sites tended to be more similar than those on different microhabitats at the same site. This implies that the species composition of oribatid communities in mangrove forests is more likely to be affected by factors responsible for microhabitat diversity (characterized specifically by the flooded trunks) than by geographical distance between the islands.     

Influence of disturbance and nitrogen addition on plant and soil animal diversity in grassland

Two key determinants of biological diversity that have been examined in aboveground and aquatic systems are productivity, or resource supply, and physical disturbance. In this study, we examined how these factors interact under field conditions to determine belowground diversity using microarthropods (mites and Collembola) as our test community. To do this, we established a field manipulation experiment consisting of crossed, continuous gradients of nitrogenous (N) fertilizer addition (up to 240 kg N ha^?1) and disturbance (imitated trampling by cattle) to produce a gradient of soil nutrient availability and disturbance. Due to the relatively short-term nature of our study (i.e. 2 years), we only detected minimal changes in plant diversity due to the experimental manipulations; in the longer term we would expect to detect changes in plant diversity that could potentially impact on soil fauna. However, disturbance reduced, and additions of N increased, aboveground biomass, reflecting the potential effects of these manipulations on resource availability for soil fauna. We found that disturbance strongly reduced the abundance, diversity, and species richness of oribatid mites and Collembola, but had little effect on predatory mites (Mesostigmata). In contrast, N addition, and therefore resource availability, had little effect on microarthropod community structure, but did increase mesostigmatan mite richness and collembolan abundance at high levels of disturbance. Oribatid community structure was mostly influenced by disturbance, whereas collembolan and mesostigmatan diversity were responsive to N addition, suggesting bottom-up control. That maximal species richness of microarthropod groups overall occurred in undisturbed plots, suggests that the microarthropod community was negatively affected by disturbance. We found no change in microarthropod species richness with high N additions, where plant productivity was greatest, indicating that soil biotic communities are unlikely to be strongly regulated by competition. We conclude that the diversity of soil animals is best explained as a combination of their many varied life history tactics, phenology and the heterogeneity of soils that enable so many species to co-exist.     

Patterns of microarthropod abundance in oak-hickory forest ecosystems in relation to prescribed fire and landscape position

We examined patterns of microarthropod abundance in oak-hickory (Quercus-Carya) forest ecosystems in southern Ohio (USA) in relation to landscape position and fire frequency. Abundances of various suborders of Acari and Collembola were determined in samples taken in June 1999 in three forested watersheds, one that had been burned annually for four consecutive springs (1996-1999), one that had been burned periodically (1996 and 1999), and an unburned control. Microarthropod abundance was significantly lower in the annually burned watershed than the periodically burned and control watersheds. Since both the periodically burned and annually burned watersheds were burned in April 1999, the lower microarthropod abundance in the annually burned watershed was not simply an immediate effect of burning. At the landscape scale, the abundance of oribatid mites was greater in xeric than intermediate or mesic landscape positions. Within any single watershed, there was no significant linear relationship between litter mass and microarthropod abundance. However, when all three watersheds were combined, there was a significant, positive relationship between litter mass and microarthropod abundance, mainly due to the annually burned watershed where there was very low litter mass and low microarthropod abundance. Both fire frequency and landscape position have significant effects on microarthropod abundance; however, those effects cannot be robustly predicted based solely on forest floor litter mass differences.     

四川紫色土丘陵区不同土地利用方式下大型土壤动物群落结构

为了解不同利用方式土地大型土壤动物群落结构,于2006年冬季和2007年春季对四川紫色土丘陵区农田边界、农田、果园和退耕林地进行了大型土壤动物调查,采用野外手捡法共采集大型土壤动物2 838只,隶属于3门9纲24类.研究结果表明:不同土地利用方式大型土壤动物群落的个体密度、类群数和DG多样性指数存在差异.冬季,农田边界的个体密度显著高于其他土地利用方式,类群数和DG多样性指数显著高于退耕林地和农田;农田的个体密度、类群数和DG多样性指数明显处于最低水平.大型土壤动物群落的个体密度和类群数在垂直分布上具有明显的表聚性.Jaccard相似性系数和Grower系数表明农田边界、果园与退耕林地三者间相似程度较高,农田与农田边界、退耕林地、果园之间相似程度较低.研究认为土地利用方式对大型土壤动物的群落结构有明显影响,农田边界的存在对大型土壤动物生物多样性的保护具有重要意义.     

Impact of earthworms on the diversity of microarthropods in a vertisol (Martinique)

In a study of a 15-year-old pasture in Martinique (French West Indies), abundance and organization of microarthropod communities were correlated with the spatial distribution of the earthworm Polypheretima elongata (Megascolecidae). In patches of high earthworm density (133 individuals m^–2), microarthropod density was significantly higher (80000 individuals m^–2) than in patches with few earthworms (31 worms m^–2 and 49000 microarthropods m^{– 2}). The diversity of microarthropod communities followed a similar pattern, the Shannon index for Collembola communities being, respectively, 3.12 and 1.82 in and outside earthworm patches. These results suggest that mesofauna abundance and diversity might be at least partly determined by the activity of larger invertebrates, as a result of the dramatic effects that the latter group exerts upon soil structure, pore distribution and food resources. Received: 7 February 1997     

Five-year trends in soil arthropod densities in pine forests with various levels of vitality

Summary A comparative field study was conducted to study the correlation between forest vitality and the abundance of soil microarthropods. During 5 years the vitality of six pine forests within the Veluwe area, the Netherlands, was estimated by the number of needle year-classes, while soils were sampled and extracted for various soil microarthropod groups. Within sites the number of needle year-classes in the forest stands fluctuated over the 5 years, while the collembolan family Sminthuridae showed a trend towards a decreasing population density and the density of the cryptostigmatid mite Platynothrus peltifer Koch increased. Among sites there was a significant positive correlation between the number of needle year-classes and the relative abundance of P. peltifer. The results imply that soil microarthropods may indicate changes in physical and chemical factors in relation to soil fertility and vitality of the trees.     

Oribatid communities (Acari: Oribatida) inhabiting saxicolous mosses and lichens in the Krkonoše Mts. (Czech Republic)

Composition, structure and diversity of oribatid communities inhabiting saxicolous mosses and lichens were studied in the Krkonoše Mts. (Czech Republic) along an altitudinal gradient reaching from submontane to alpine belt. Samples of various saxicolous mosses and lichens from 197 stands were collected. Impact of altitude and dominant moss or lichen species on community structure were analysed. Data were evaluated using divisive cluster analysis and direct ordination analysis. Altogether 104 oribatid species were recorded. Four groups of saxicolous habitats, which differ in the composition of their oribatid communities, were distinguished:1. Mosses below the upper forest line with accessory higher plants growing on their surface. Higher plants indicate favourable moisture conditions and an appreciable degree of humus layer development. Their oribatid mite community is rich in number of frequent species and consists of ubiquitous species, ubiquitous species with higher requirements for moisture and amount of decaying organic matter, a high number of soil dwelling species and several hygrophilous species.2. Mosses below the upper forest line without accessory higher plants. They predominantly include mosses with no or only a weakly developed humus layer. Their oribatid mite community is composed mainly of ubiquitous species and a few soil dwelling species.3. Mosses in open areas above the upper forest line. Their humus layer is not developed at all or only weakly. Humidity and temperature fluctuations are here much higher compared with mosses below the upper forest line, which are protected by the specific forest microclimate. Their oribatid mite community is poor in number of frequent and dominant species and consists predominantly of Oribatula cf. pallida and two specialised species living exclusively in mosses and lichens (Mycobates tridactylus and Trichoribates monticola).4. Saxicolous lichens. Their oribatid community comprises ubiquitous species, species frequent both in mosses and lichens and several species with a strong affinity to lichens (Mycobates carli and five species of the genus Carabodes).     

Effects of Soil Development Time and Litter Quality on Soil Carbon Sequestration: Assessing Soil Carbon Saturation with a Field Transplant Experiment along a Post‐mining Chronosequence

In previous studies, the rate of soil carbon (C) sequestration decreased with increasing age of post‐mining soils. It was also shown to depend on plant biomass and earthworm bioturbation. Here, a soil transplant experiment was used to determine whether this decrease is caused by soil C saturation or other factors (such as bioturbation and litter input). Soils collected on 15‐, 25‐ and 50‐year‐old successional sites, dominated by willow (Salix caprea L.) and birch (Betula pendula Roth), and on a 50‐year‐old site reclaimed by the planting of alder (Alnus glutinosa L.) were placed in plastic boxes that were accessible to soil macrofauna. The boxes were buried in the 50‐year‐old reclaimed site and supplemented with either alder litter or successional (willow and birch) litter. Soil C content and soil C fractions (hot water C, particulate organic C, particulate organic C bound in aggregates and C bound to mineral soil) were studied. After 1 year, the C content increased by 2–5%, but there was no effect of soil source or litter type. For all C fractions, the relationships between change in C content and initial C content were described by bell‐shaped curves. Easily available C fractions were saturated earlier than more recalcitrant fractions. Despite these saturation tendencies in individual soil organic matter pools, the soil was evidently far from saturation after 50 years of soil development. The decrease in C sequestration with soil age previously observed for this soil was probably caused by a decrease in litter input rather than by C saturation. Copyright © 2016 John Wiley & Sons, Ltd.     

Ecological risks of the use of sewage sludge as fertilizer in soil restoration: effects on the soil microarthropod populations

Experimental plots were laid out in a limestone quarry in Girona (Catalonia, Spain) to test the effects of sewage sludge on the soil microarthropod populations. Two different doses of sludge (7·5 per cent and 15 per cent) were applied to fertilize soil that was used to restore a quarry after opencast mining. Mean annual arthropod density increased when sludge was applied, but the 15 per cent dose caused an impoverishment of the community structure and a decrease of the soil oribatid diversity. Julidae (Diplopoda) and large predators of the mite family Parasitidae (Mesostigmata) were the most depressed taxa, whereas some groups depending on the availability or quality of organic matter (such as the immature Coleoptera or the Uropodidae), or on water availability (such as Collembola) were stimulated. Among the oribatids, Punctoribates sp. was the most depressed, whereas the more common little Oppias were significantly favoured. The application of sludge at a dose of 15 per cent must be avoided in order to preserve the soil biodiversity. Copyright © 1999 John Wiley & Sons, Ltd.     

Soil pore volume and the abundance of soil mites in two contrasting habitats

Microarthropods are mainly found in the organic layer of soils but show high spatial variability in abundance that remains poorly understood. A factor that could be influencing the abundance of microarthropods is the soil pore volume. Consequently, we tested the hypothesis that mite abundance is related to soil pore volume in two contrasting habitats. Heather moorland and birch woodland, with contrasting humus forms, showed high within-habitat variation in soil pore volume and mite abundance. The abundance of oribatid mites in both habitats and the abundance of mesostigmatid mites in heather moorland were strongly and positively related to the volume of pores in the range 60–300 μm. This supports the hypothesis that mite abundance is influenced by soil pore volume and we stress that soil structure should be considered as an explanatory variable when studying microarthropod communities.     

Dual roles of tillage erosion in lateral SOC movement in the landscape

The facts that the global carbon budget cannot be currently balanced and current estimates of agricultural sources and sinks may be inaccurate, may be linked to unaccounted‐for erosion‐induced changes in soil organic carbon (SOC). A closed landscape with field banks and an open landscape without field banks were selected from two sites located in Jianyang County, Sichuan Province, and Zhongxian County, Chongqing Municipality, respectively. In these landscapes, the role of tillage and water erosion was examined using measurements of soil redistribution in relation to ¹³⁷Cs radionuclide depth‐stratigraphy, to elucidate the mechanism of SOC depth distribution in the soil profile and resultant stocks in agricultural landscapes of terraced field systems. Changes in the ¹³⁷Cs inventory at different landscape positions depend on both ¹³⁷Cs concentrations of individual subsample layers (5‐cm depth) and the vertical extent of ¹³⁷Cs depth distribution in the terrace system with field banks, while the changes are only associated with the vertical extent of ¹³⁷Cs depth distribution in the terrace system without field banks because of similar ¹³⁷Cs concentrations of individual subsample layers. The profile shape of SOC depth distribution exhibits notable differences between the upper and lower parts of the terrace in systems with field banks, but no apparent differences were found in the systems without field banks and the SOC profile shape is similar to that of the upper part of the terrace in systems with field banks. It is suggested that SOC depth distribution in these two types of terraced field systems is controlled by different soil erosion patterns. Tillage erosion playing a dominant role in the process of soil erosion within a landscape can increase SOC stocks. However, SOC depletion takes place in situations where the two processes of tillage and water erosion are both important and tillage erosion acts as a delivery mechanism for water erosion. We conclude that tillage erosion plays a dual role: enhancing carbon storage at depositional positions, and accelerating carbon depletion when combined with water erosion within the same landscape.     

Changes in the community composition and trophic structure of microarthropods in sporocarps of the wood decaying fungus Fomitopsis pinicola along an altitudinal gradient

Soil microarthropods colonize a wide range of habitats including microhabitats such as earthworm burrows, ant nests, tree trunks, moss mats and wood decaying fungi. While many of these microhabitats have been investigated intensively, the role of wood decaying fungi as a habitat and food resource for microarthropods found little attention. We investigated the density, community structure, reproductive mode and trophic structure of microarthropods, in particular oribatid mites, in the wood decaying fungus Fomitopsis pinicola (Schwarts: Fr) Karst. along an altitudinal gradient in Germany spanning from 350 m to 1160 m. Microarthropods were extracted from sporocarps, and stable isotope ratios (¹⁵N/¹⁴N; ¹³C/¹²C) of the fungus and the microarthropods were measured. Densities of most microarthropod taxa were highest at lower altitudes and decreased with increasing altitude. Oribatid mites were the dominant animal taxon. Their community structure gradually changed with altitude. Stable isotope ratios indicated that oribatid mite and other arthropod species occupy distinct trophic niches but most do not feed on F. pinicola. Notably, species of the same genus, e.g. Carabodes, occupied different trophic niches. Most oribatid mite species in F. pinicola reproduced sexually which is similar to the bark of trees but in contrast to the soil where most species reproduce via parthenogenesis. The findings indicate that (1) at high altitudes microarthropod density in fungal fruiting bodies is limited by low temperatures reducing animal metabolism and reproduction, and this also affects oribatid mite community structure, (2) despite the uniform habitat trophic niches of oribatid mite species differ and this also applies to morphologically similar species of the same genus, and (3) feeding on F. pinicola or associated resources facilitates the dominance of sexual reproducing species.     

内盖夫荒漠中小型土壤节肢动物群落的时空变化

Desert ecosystems are characterized by sparse vegetation that affects both abiotic parameters and soil biota along the soil profile.This study was conducted in 2010–2011 in a loess plain in the northern Negev Desert highlands, Israel, to test two main hypotheses:1) the abundance and diversity of microarthropods would vary seasonally in the top 30-cm soil layer, but would be relatively stable at soil depths between 30 and 50 cm and 2) soil microarthropods would be more abundant in soils under shrubs with large litter accumulations than under shrubs with less litter or bare soil. Soil samples were collected each season from the 0–50 cm profile at10-cm intervals under the canopies of Hammada scoparia and Zygophyllum dumosum and from the bare interspaces between them.Soil moisture and soil organic carbon in the top 30-cm layers varied seasonally, but there was little variation in the soil layers deeper than 30 cm. Soil mites were most abundant in the top 30-cm soil layer in autumn and winter, with the highest number of families found in winter. There were no differences in soil microarthropod abundance attributable to the presence or absence of shrubs of either species. The microarthropod communities of the microhabitats studied consisted of Acari, Psocoptera, and Collembola. The Acari were mostly identified to the family level and were dominated by Oribatida(55%) and Prostigmata(41%) in all seasons and microhabitats, while the psocopterans were most abundant in summer. These results are opposite to those obtained in other studies in similar xeric environments. Moreover, our findings were not in line with our hypothesis that a better microhabitat played a major role in microarthropod community composition, diversity, and density.     

Reactions to soil acidification in microarthropods: Is competition a key factor?

Summary Acidification of raw humus soil in coniferous forest areas leads to characteristic changes in the microarthropod community. Certain species are calciophilic and decrease in abundance, while others are acidophilic and increase in abundance. The simplest explanation for these changes is that population levels are directly related to soil pH. This hypothesis was tested by growing small populations of selected species in monoculture at different pH levels. Three acidophilic species were tested, the collembolan Mesaphorura yosii, the oribatid mite Nothrus silvestris, and the astigmatid mite Schwiebea cf. lebruni. A slightly calciophilic collembolan, Isotomiella minor, was also included. For all species, population growth was lowest in acidified raw humus. Even acidophilic species seem to have an optimum at a high pH. It is assumed that their success in low-pH soils is due to their ability to compete under these conditions. Competition may be a key factor in microarthropod reactions to soil acidification.Dedicated to the late Prof. Dr. W. Kühnelt     

Diversity of soil mite communities when managing plant communities on set-aside arable land

When restoring former agricultural land to more low-nutrient input ecosystems, the establishment of a plant community can be enhanced by sowing desirable species. In this study our aim was to determine whether management of the plant community influences the microarthropod community. We carried out a field experiment in three European countries on set-aside arable land and determined soil mites from the sites in Sweden, The Netherlands and Spain. Experimental plots on set-aside arable land were sown with high (15 species) or low (4 species) plant species seed mixtures; other plots were colonized naturally. A field with continued agricultural practices and a later successional site (target site) were used for comparison with the experimental plots. Soil from the later successional site was inoculated into half of the plots. Abandoning agricultural practices increased the density of mites at one site while the number of mite species was not affected. Sowing plant seeds had no effect on mite densities at any of the sites. The community composition of mites changed in response to management of the plant community, as shown by canonical correspondence analysis. Among the functional groups of mites, saprophytes generally dominated on all plots at all sites. Mites parasitic on insects were not present on fields with continued agricultural practice in Sweden and The Netherlands, and might thus be regarded as an indicator of an increase in trophic complexity in the sown and naturally colonized treatments. Predatory and plant parasitic mites showed no consistent pattern in relation to the treatments of the three sites. Soil inoculation treatment had only a minor impact on the soil mite communities.