Spatial distribution patterns of soil mite communities and their relationships with edaphic factors in a 30-year tillage cornfield in northeast China

Effect of Grazing Management on Predator Soil Mite Communities (Acari: Mesotigmata) in Some Subalpine Grasslands from the Făgăraş Mountains-Romania

For the first time in Romania, a complex study was conducted on soil mite communities from two types of managed grasslands: ungrazed and intensively grazed. The study was accomplished in August 2018, in the Făgăraş Mountains. Within the soil mite communities (Mesostigmata), 30 species were identified, from 80 soil samples. The following population parameters were investigated: species richness, numerical abundance, dominance, Shannon index of diversity, evenness and equitability. Eight environmental variables were also measured: soil and air humidity; soil and air temperature; soil pH; resistance of soil to penetration; soil electrical conductivity; and vegetation coverage. The results revealed that species richness, Shannon index of diversity, evenness and equitability indices had higher values in ungrazed grasslands, whereas in intensively grazed areas, the numerical abundance and dominance index had significantly higher values. The species Alliphis halleri was dominant in the ungrazed grasslands. Each type of managed grassland was characterised by specific environmental conditions, which had an important influence, even at the species level.

Distribution characteristics of insect diversity in long-term fixed monitoring plots in Northeast China

The spatial patterns of field arthropod communities are an essential part of ecology and can provide fundamental data regarding field ecological processes and reveal the mechanism of ecosystem biodiversity maintenance. This study investigated the spatial distribution pattern of field insect communities to detect the spatial relationships between insect communities in farmland. The study site was located at the Dehui Agro-ecological Experimental Station of Black Soil, Jilin, China. Insect communities and environmental factors were sampled at 121 uniformly distributed points in a 400 × 400 m plot in August, September, and October 2015. The analysis revealed that insect communities from June to October demonstrated significant spatial correlation, and 6085 samples of 47 species and 47 families in 11 orders were collected from the insect community in the farmland. The farmland insect community structure changes and dynamic changes of nutritional function groups occur with time. According to the 400 x 400 m plot, the diversity of farmland insect communities and functional groups is maintained at a relatively high and stable level. In this study, a total of 6085 samples of corn farmland insects were obtained using the fluke method and direct observation method, including 11 orders, 26 families and 47 species, 4 absolute dominant populations, 6 main dominant populations, and 37 other populations. These studies can provide help for pest control in the spring corn area of Northeast China.