Abstract:

Aims: Using an agricultural soil permanent plot, we wanted to reveal the spatial distribution patterns of soil organisms and functional diversity, as these are important metrics for maintaining soil organism diversity and improving agricultural soil quality.
Methods: In October 2020, 210 soil samples were collected from a large permanent farmland soil plot (9 ha) in Shangqiu, Henan Province. Soil mites were extracted by Tullgren’s funnel method in the laboratory. The soil mites were identified to species and their body length and width were measured to illustrate both the spatial distribution pattern of species diversity as well as body size of soil mites in wheat-maize rotation farmland.
Results: (1) A total of 17,256 adult mite individuals were captured, of which oribatid mites were the dominant group (94.67%). Results of MGP analysis showed that the oribatid mite community belonged to P-type, indicating that it was strongly affected by human factors. Niche breadth and overlap analysis showed that for higher degrees of evolution, niche width of oribatid mites increased, and for closer degrees of evolution, oribatid mites experienced greater competition. (2) Values of Moran’s I index showed that from 20 m to 100 m, the individuals of dominant soil mite community were significantly positively correlated with body length and body width; yet from 220 m to 300 m, individuals of soil mite community and four dominant species had a negative spatial autocorrelation. A semi-variance function showed that the spatial variation of species, individual number, body length and width of oribatid mites were mainly affected by deterministic processes, while the spatial variation of mesostigmatid mites was affected by both deterministic and stochastic processes. (3) There was a weak negative correlation between the individual number of soil mites and body length and body width, which generally exists in each community and dominant species of soil mites.
Conclusion: This study suggests that the spatial pattern of species and functional diversity represented by mite body length and width should be considered when evaluating maintenance mechanisms of soil mite community and for protecting the diversity of soil mites.

Key words: wheat-maize rotation, soil mites, diversity, body length, body width, spatial pattern