Bremia is a genus of biotrophic oomycetes reported to cause downy mildew infection on over 200 species from 40 different genera of plants in the daisy family (Asteraceae). Taxonomy of Bremia has been neglected as species lack clear-cut morphological differences and host-specificity was not considered to be sufficient for species delimitation for a long time. However, molecular phylogenies revealed that a narrow species concept should be applied and that the type species Bremia lactucae, which most Bremia occurrences were attributed to, is restricted to Lactuca sativa and Lactuca serriola, and that many distinct lineages with a high host-specificity exist in the genus. While a comprehensive revision is still outstanding and many species remain to be described, the discovery of the undescribed Bremia species in autumn hawkbit (Scorzoneroides autumnalis) at the Bl & aacute;v & iacute;k research station in Iceland motivated taking the first steps into this direction. Thus, as a representative of one of the many overlooked Bremia species, Bremia blauvikensis is introduced here, and the taxonomy of the genus is shortly discussed.
Pesticides can harm non-target soil fauna and plant communities. Their influence may extend to sites adjacent to agricultural fields, including protected areas. We measured contamination (type, number and concentration) of currently used pesticides and the physicochemical parameters in soils of agricultural fields and adjacent dry grasslands in two regions of Germany. We assessed their effects on community structure and species diversity of vegetation, soil nematodes and oribatid mites to see whether they were comparable between groups. The fields had higher pesticide numbers and concentrations compared to the grasslands, and lower species richness for all three taxonomic groups. We found a significant negative correlation between the total number of pesticides in a soil sample and the species richness of plants and nematodes. In addition, herbicide mixtures reduced species richness of plants and root-feeding nematodes, and fungicide mixtures reduced species richness of plants and nematodes. There was no clear effect of pesticides on oribatid mites. The inconsistent response of different taxa to pesticides calls for usage of natural communities in impact assessments. Pesticide effects in protected sites near agricultural fields suggest establishment of buffer zones.
Mongolian steppes are still under traditional land use by mobile pastoralism and remain relatively intact. Traditional ecological knowledge (TEK) has always played an essential role in herders' assessments of pasture conditions, and decision-making regarding their movements. In the last two decades, Mongolia's rapid socio-economic development resulted in dramatically increasing livestock numbers and expanding settlements, raising concerns about rangeland degradation associated with potential declines in herders' TEK.We compared quantitative and qualitative data from interviews on herders' TEK and standard ecological assessments to assess the level of congruence. In 2020, a total of 367 households across ten sampling sites were interviewed about pasture condition, TEK on forage and degradation indicator plants. For the same sites, we collected field-based data on plant species richness, composition and biomass, as well as remote sensing-derived biomass estimates.Our results highlight variance in TEK: even within the same sites, there were widely diverging perspectives on pasture condition and its trends, forage palatability and degradation indicator plants, suggesting that there is limited exchange among herders. Multivariate analyses showed that herders' assessments had a moderate association with field-based vegetation data, reinforcing that comprehensive evaluations of pasture conditions still require field-based assessments. These findings underscore the need for stronger communication between scientists and herders, as well as enhanced transfer of TEK regarding current and changing pasture conditions. Since TEK and its transmission play a key role in herders' movement decisions and are vital for future rangeland monitoring, capacity building is recommended to support the development of sustainable land use policies that uphold ecological integrity.
Soil food webs channel most of the energy in terrestrial ecosystems. Temperate and tropical forests host different soil invertebrate communities, but consequent differences in the structure and functioning of soil food webs between these major biomes remain unknown. Here, we calculate energy fluxes to explore generic patterns in biomass and energy distribution across micro-, meso- and macrofauna in forest ecosystems spanning from southern taiga to tropical rainforests. Tropical soil food webs have either larger (monsoon forest) or smaller (rainforest) animal biomass than temperate ones, but have consistently higher energy flux, higher share of large organisms (macrofauna) in total biomass and distinct energy distribution. Specifically, tropical soil food webs have proportionally higher predation rates than temperate soil food webs and rely more on plant consumption (living roots), but less on bacterial, fungal and litter consumption. Earthworms act as food-web engineers promoting detrital energy pathways (litter, soil and deadwood consumption) in mixed broadleaved forests overriding climate-associated differences among forests. Our study shows a major change in soil food web from “brown” temperate to “green” tropical functional state, explaining functional implications of soil invertebrate community turnover across biomes. The structure and functioning of soil food webs between biomes remains unknown. Here, tropical soil food webs are shown to have higher energy flux, predation and herbivory than temperate soil food webs which are based on litter and microbial biomass.
Cypriniformes, the most species-rich order of freshwater fishes (~5,000 species), represents a key lineage for understanding vertebrate diversification in freshwater ecosystems. This clade includes several highly miniaturized and understudied lineages whose phylogenetic placements have long remained contentious. Here, we present the first phylogenomic analysis of Cypriniformes with complete family-level representation and broad genus-level coverage, encompassing 316 species comprising approximately 30% of all described genera. Our dataset integrates 257 newly assembled genomes with publicly available resources and analyzes multiple sets of genome-wide markers using both concatenation-based and coalescent-aware approaches. The general concordance among analytical frameworks indicates that the backbone topology of Cypriniformes is now established, allowing clear identification between well-supported clades and regions of persistent conflict. Our results strengthen the evolutionary relationships of several miniaturized lineages, while identifying recalcitrant relationships shaped by both biological processes and model artefacts that can yield superficially similar patterns of phylogenetic conflict. Our study substantially expands genomic representation and establishes a phylogenomic foundation for future comparative, developmental, and evolutionary research in this freshwater radiation. ### Competing Interest Statement The authors have declared no competing interest. Swiss National Science Foundation, 310030_185120 Basler Stiftung für Biologische Forschung TAMU HATCH, TEX09452-1
