Responses of soil-inhabiting mesostigmatid mites to deforestation and disturbance in oak (Quercus brontii) forests of southwestern Iran

The impacts of deforestation on edaphic mesostigmatid mites were investigated in oak forests of Lordegan, southwestern Iran, from April to October. A total of twenty-one species belonging to eighteen genera and ten families were collected and identified. The Shannon-Wiener, Simpson, Jaccard's and Margalef biodiversity indices were used for data analyses. Among the collected species, Antennoseius bacatus with 29% and Sessilunchus hungaricus with 16% relative abundance were the most abundant and dominant species in human-disturbed and natural forests, respectively. The estimated values were higher in natural oak forest than in disturbed and cultivated habitat. Significant differences were observed in soil nitrogen content and soil organic carbon between the two habitats, but not in pH values. Significant effects of sampling time and habitat were found on all four indices, but the effect of their interactions on these indices was not significant. It can be concluded that the changes in soil quality that resulted from deforestation may have a major role in reducing the soil mite density and related diversity indices in disturbed forests.

Know your campus: salient research potential of prostigmatic soil mite fauna (Acariformes: Prostigmata, Endeostigmata) within university campus area

The study provides the list of soil mites from suborder Prostigmata in selected habitats of Morasko Campus of Adam Mickiewicz University in Poznań. Representatives of 21 families belonging to 58 genera and 139 species were found in 20 collected samples. One family, 11 genera and 26 species are new to the fauna of Poland and two species new to the fauna of Europe.

Immediate Effects of Prescribed Burning on Soil Mite (Acari: Oribatida) Communities in a Scots Pine (Pinus Sylvestris) Forest, Latvia

Prescribed burning is used to maintain and restore habitats, to protect and increase species bio-diversity. Knowledge about soil fauna is limited, especially on community responses to fire disturbances. The aim of this study was to determine the immediate effects of prescribed burning on soil armoured mite (Acari: Oribatida) communities, vegetation cover and soil physiochemical properties in a boreal Scots pine forest in Latvia. Soil samples were collected on the day of the prescribed burning in the protected landscape area “Ādaži” and 16 days after. No significant changes in abiotic factors were found. Fire significantly decreased the vegetation cover. After the burning, the total number of oribatid mites decreased by 93%, and the number of species by 77%. Changes in oribatid mite communities were significantly influenced by fire severity. The number of individuals decreased among all taxa, except Brachychthonioidea spp. and Cosmochthonius lanathus. A significant decrease in abundance was observed in previously abundant species — Suctobelbella spp., Oppiella nova and Tectocepheus velatus. After the burning, Suctobelbella spp. was an eudominant and Tectocepheus spp. was a dominant genus.

Soil mite communities (Acari: Mesostigmata) as indicators of urban ecosystems in Bucharest, Romania

The aim of the present study was to establish the effect of management type and of environmental variables on the structure, abundance and species richness of soil mites (Acari: Mesostigmata) in twelve urban green areas in Bucharest-Romania. Three categories of ecosystem based upon management type were investigated: protected area, managed (metropolitan, municipal and district parks) and unmanaged urban areas. The environmental variables which were analysed were: soil and air temperature, soil moisture and atmospheric humidity, soil pH and soil penetration resistance. In June 2017, 480 soil samples were taken, using MacFadyen soil core. The same number of measures was made for quantification of environmental variables. Considering these, we observed that soil temperature, air temperature, air humidity and soil penetration resistance differed significantly between all three types of managed urban green area. All investigated environmental variables, especially soil pH, were significantly related to community assemblage. Analysing the entire Mesostigmata community, 68 species were identified, with 790 individuals and 49 immatures. In order to highlight the response of the soil mite communities to the urban conditions, Shannon, dominance, equitability and soil maturity indices were quantified. With one exception (numerical abundance), these indices recorded higher values in unmanaged green areas compared to managed ecosystems. The same trend was observed between different types of managed green areas, with metropolitan parks having a richer acarological fauna than the municipal or district parks.

Ground Predator Activity-Density and Predation Rates Are Weakly Supported by Dry-Stack Cow Manure and Wheat Cover Crops in No-Till Maize

Because it keeps land in production, conservation programs that focus on in-field habitat manipulations may help farmers better support predators than by building predator habitat around fields. We investigated two in-field habitat manipulations that benefit producers and soil quality: fertilizing with dry-stack cow manure and planting a wheat cover crop. We hypothesized that, compared with inorganic fertilizer and fallow plots, both treatments augment habitat and residue and support more small arthropods that can serve as alternative prey for larger predators. As a result, we expected manure and the cover crop to increase ground-active predators. In turn, these predators could provide biological control of pests. Each year in a 3-yr field experiment, we applied manure and in 2 yr planted a wheat cover crop. We found that both planting a cover crop and applying dry-stack manure increased the plant cover in May. In the last year, this translated to greater soil mite (Acari) density. At the end of the experiment, however, neither manure nor the wheat cover crop had increased residue on the soil surface. As a result, our treatments had inconsistent effects on predator activity-density, especially for carabids and spiders. We observed strong edge effects from neighboring grass alleys on carabid activity-density. Regardless of treatment, we observed high predation of sentinel prey. We conclude that even without cover crops or organic fertilizer, the stability of no-till maize and increased weeds in fallow treatments generate sufficient habitat complexity and alternative prey to support robust predator communities.

Soil mite (Acari, Mesostigmata) biomass, species richness and diversity in soil and decayed logs of European Beech (Fagus sylvatica L.) forests

The European beech (Fagus sylvatica L.) is a dominant tree species in European forests and it has a huge ecological significance and high economic value. Due to its large dimensions, it can produce large amounts of decayed wood (CWD) which may be critical for maintaining the population of many rare species including mites. Many studies focused on mite (Mesostigmata) abundance, species richness, or diversity in CWD, however, our knowledge on mite biomass is still scarce. Therefore, the main aim of that study was to recognize the Mesostigmata biomass in logs and adjacent soil. In total, 90 samples (125 cm3, 5 cm depth) were collected from European beech logs and soil with litter thickness. Soil samples were collected from ecotone zone (soil near the log) and further three distances—0.5 m, 1.0 m, 1.5 m away from the log. Body length and width were measured for each individual of rare species and in the case of common species at least for 10 individuals. Our study revealed the highest mite biomass in CWD and soil near to the log (ecotone). Total male biomass was the highest in CWD and differed significantly from all other soil microhabitats. Female biomass did not differ between soil and CWD, whereas deutonymphs biomass differed between CWD and soil 1.0 m away from the log. Mean abundance, species richness, and diversity did not differ between the microhabitats. Decaying logs were dominated by Janietella pulchella whereas soil by Veigaia nemorensis. In conclusion, decayed European beech logs maintain the highest male and deutonymph biomass when compared to adjacent soil. Beech logs are important microhabitats for Mesostigmata mite communities, where they reached the highest abundance.