No abstract

The invasion of Solidago is one of the main threats to the biodiversity of natural meadows, leading to changes in animal and plant communities, as well as soil features. We compared effects of soil microclimatic conditions (temperature and moisture) and the availability of potential protein sources (dry mass of epigean invertebrates) on ants between meadows invaded by Solidago altissima and S. canadensis and those uninvaded. Our results showed that the ant communities were different between the uninvaded and invaded meadows, with reduction of ant abundance and species richness in the latter. Myrmica spp. were abundant in the uninvaded meadows, whereas Lasius niger was the dominant species in the invaded ones. We found that the lower moisture negatively influenced the abundance of Myrmica species in the Solidago‐invaded meadows. Moreover, the epigean invertebrate dry mass, as an estimation of the availability of protein sources, varied between the two types of meadows, with a higher abundance in the uninvaded ones. The abundance of Myrmica ants with narrower ecological requirements showed a positive correlation with the invertebrate biomass in the invaded meadows. In contrast, the abundance of L. niger with broad ecological requirements was negatively correlated with the invertebrate biomass in the invaded meadows, possibly as a strategy to reduce interspecific competition. Our study showed that the invasion of Solidago plants caused changes in the abundance and species composition of ant communities through modification in microhabitat conditions, that is, decreasing soil moisture, reducing biomass and changing distribution of prey invertebrates.

Urban green areas have become an important tool for biodiversity conservation in cities. However, land use and the different management practices applied to these areas determine their effectiveness as biodiversity refuges within cities. In our study, we compare the biodiversity of three bioindicator groups of arthropods (ants, spiders and harvestmen) found in eleven urban green sites in Warsaw (Poland). The studied sites represent three categories of management: botanical gardens, public parks and urban woodlands. Our aim was to determine the effect of the type of management (as urban green categories) on arthropod communities in urban areas.

A bstract: Tlie species composition, nest density, structure and ecological profile of an ant community were studied within a transect encompassing the forest interior, forest edge and a belt-shaped clearing in a moist mixed pine forest habitat (Querco roboris-Pinetum) in the Kampinos Forest (Central Poland) in the context of direct and indirect human impact and the bioindicator importance of ants. Altogether, 19 ant species were found; the most abundant ones (in respect of number of nests) in the entire habitat under study were Temnothorax crassispinus (Karav.) and Myrmica rubra (L.). All analysed parameters of individual subcommunities, except for nest density (highest on the forest edge, lowest in the cleared belt), showed a gradient pattern of variability, with species richness and the index of general diversity increasing and the dominance index decreasing within the transect from the forest interior to the cleared belt. Differences between the two subcommunities from the forested area (forest interior and forest edge), both highly dominated by T. crassispinus, were, in every way, much smaller than those between either of them and the subcommunity from the cleared area, where M. rubra prevailed.