Extension of the soil monitoring network via tea bag initiatives: A 3000 km latitudinal gradient in European Russia.

The increasing popularity and recognition of citizen science approaches to monitor soil health have promoted the idea to assess soil microbial decomposition based on a standard litter sample - tea bags. Although tea bag initiatives are expanding across the world, the global datasets remain biased in regard to investigating regions and biomes. This study aimed to expand the tea bag initiative to European Russia, which remains a "white spot" on the tea bag index map. We also added urban soils into the analysis, which were underestimated previously. We compared the standard and local tea brands to explore possible adaptations of the standard approach to regions with limited access to standard tea brands. The established monitoring network included natural and urban sites in six vegetation zones along a 3000 km latitudinal gradient. There was a very close linear relationship (R2 = 0.94-0.98) in the mass loss of alternative and standard tea litter. The mass loss of green tea in soil along the latitudinal gradient showed an increasing trend from north to south. Variations in the microbial decomposition of green tea were mainly explained by the latitudinal gradient, with low soil temperature identified as key factors hampering decomposition. Mass loss of the more recalcitrant rooibos tea was mainly determined via land use, with decomposition rates on average 1.3 times higher in urban soils. This pattern was in line with higher soil temperatures and pH in urban sites compared to natural counterparts. The findings of our study could prove valuable in extending the tea bag network of soil decomposition assessment into broader territories, including urban areas. Additionally, they could facilitate the involvement of citizen science and complete the database for C cycle modeling depending on climatic conditions.

Opportunistic Mycobiota of Dust in Cities of Different Climate Zones: Murmansk and Moscow.

For the first time, mycological analysis of dust, including assessment of opportunistic fungal species, was carried out for the urban ecosystems of air, vegetation, and paved surfaces in different climate areas (the cities of Murmansk and Moscow). The combined effect of environmental factors (climate, functional zone, and substrate type) on qualitative and quantitative parameters of micromycete communities was assessed using MANOVA and cluster analysis. It was found that the abundance of culturable mycobiota in the air, on tree leaves, and on paved surfaces was lower in Murmansk than in Moscow. In both cities, approximately a half of fungal species were opportunistic pathogens. The relative abundance of opportunistic fungi of the BSL-2 group was higher in the air of the traffic zone in both cities and of the residential zone in Moscow. In the residential and traffic zones of Moscow, the most abundant species in the air in on the road dust were Aspergillus fumigatus and A. niger, while in Murmansk communities were dominated by members of the genera Cephalosporium, Scopulariopsis, and Trichoderma, which are less pathogenic for humans. The most significant factors affecting the abundance and species diversity of micromycetes, including opportunistic fungi, were the substrate type (air, leaves, or paved surfaces) and the climate, while the effect of the functional zone was not significant. The recreation zones of cities located in different climate regions are the most favorable for humans due to lower abundance of opportunistic fungi in the air and to lack of micromycetes of the BSL-2 and BSL-3 groups. However, the abundance of potentially pathogenic species on the surfaces of leaves and roads in this zone was higher than in the air. Therefore, it can be recommended that city residents minimize their contact with the leaves surface and road pavements, which is especially relevant for toddlers, so as to diminish the probability of encountering opportunistic mycobiota that potentially represents a health hazard.