Karel Fajmon

Diversity of fungi and bacteria in species-rich grasslands increases with plant diversity in shoots but not in roots and soil

&NA; Microbial communities in roots and shoots of plants and in soil are important for plant growth and health and take part in important ecosystem processes. Therefore, understanding the factors that affect their diversity is important. We have analyzed fungal and bacterial communities associated with plant shoots, roots and soil over a 1 km2 area in a semi‐natural temperate grassland with 1‐43 plant species per 0.1 m2, to describe the relationships between plant and microbial diversity and to identify the drivers of bacterial and fungal community composition. Microbial community composition differed between shoots, roots and soil. While both fungal and bacterial species richness in shoots increased with plant species richness, no correlation was found between plant and microbial diversity in roots and soil. Chemistry was a significant predictor of bacterial and fungal community composition in soil as was also the spatial location of the sampled site. In this species‐rich grassland, the effects of plants on the microbiome composition seemed to be restricted to the shoot‐associated taxa; in contrast, the microbiomes of roots or soil were not affected. The results support our hypothesis that the effect of plants on the microbiome composition decreases from shoots to roots and soil. &NA; Graphical Abstract Figure. Grassland plant diversity influences the diversity of bacterial and fungal communities in plant shoots but not in roots or soil.

Reversing expansion of Calamagrostis epigejos in a grassland biodiversity hotspot: hemiparasitic Rhinanthus major does better job than increased mowing intensity

Questions Can hemiparasitic Rhinanthus major originating from a local population suppress the competitive clonal grass Calamagrostis epigejos and reverse its expansion in species-rich semi-natural grasslands? Does sowing seeds of R. major facilitate restoration of target meadow vegetation? Is R. major more beneficial for biodiversity restoration/conservation than increased mowing intensity, a conventional measure to suppress C. epigejos? Location Certoryje National Nature Reserve, Bile Karpaty (White Carpathians) Protected Landscape Area, Czech Republic. Methods We conducted a before-after-control-impact (BACI) experiment in meadow patches heavily infested by C. epigejos: eight blocks, each containing four plots with four treatment combinations: (i) traditional management, i.e. mowing once in summer, (ii) mowing in summer and autumn (iii) mowing in summer and seed sowing of R. major (iv) mowing in summer and autumn and seed sowing of R. major. Aboveground biomass of C. epigejos and vegetation composition of each of the plots were monitored every year from 2013 to 2016. To assess the effects of treatments, we analyzed biomass production of C. epigejos, herb layer cover and vegetation composition. Results Both the sowing R. major and an additional autumn meadow cut significantly suppressed C. epigejos. Their effects were additive and of comparable size. Both treatments also had significant but markedly different effects on community composition. R. major facilitated directional community composition change towards the regional Brachypodio-Molinetum meadows. By contrast, increased mowing intensity significantly decreased frequency of threatened species, which however may have also been influenced by R. major. Conclusions Sowing of autochtonous R. major seeds was demonstrated as an efficient tool to suppress C. epigejos and facilitate community restoration. It can be combined with an additional meadow cut to further accelerate the decline of the grass. The additional cut should however be used as a short term practice (1-2 years) only to minimize potential negative effects of its long-term application on some threatened plant species. The effects of R. major are comparable to those of R. alectorolophus reported previously. As a species occurring naturally in species-rich dry grasslands, R. major has a broader and longer-term application potential than R. alectorolophus in ecological restoration and conservation of these communities. This article is protected by copyright. All rights reserved.