STRUCTURE OF COLLEMBOLA COMMUNITIES IN THE URBAN GRADIENT OF RÎGA CITY

The world's increasing urbanisation and the deterioration of human quality of life in major cities have redirected the focus of urban planning toward green infrastructure improvement and, as a result, increased the research of urban ecosystems. This article analyses changes in the structure of Collembola communities in soil in the urban-rural gradient in the city of Rîga, Latvia. Soil samples were collected in 21 randomly selected sample plots within six urban habitats: street edge grasslands, downtown parks, private houses, cemetery grasslands, and urban and suburban forests. Soil samples were taken at the end of September/beginning of October 2017. A steel soil corer (D 50 mm, surface area 19.6 cm^2, depth 10 cm) was used. In each plot, three soil samples were taken with a soil corer. Collembola were extracted from pooled samples from each habitat using a Berlese-Tullgren extractor. Nonmetric Multidimensional Scaling (NMS) ordination of Collembola data in sample plots yielded three statistically significant axes (p < 0.01). The first axis explaining 49% of the data variation coincided with the urban-rural gradient. Species richness declined towards the city centre, while the Simpson’s Dominance Index increased. The species Mesaphorura macrochaeta predominates in the central habitats, while Parisotoma notabilis dominates in suburban forests.