Stresses

White leaf spot disease [Neopseudocercosporella capsellae (Ellis & Everhart) S.I.R.Videira & P.W.Crous] poses a significant threat to rapeseed production globally. The herbicides atrazine and glyphosate are widely applied to herbicide-tolerant major crops, including rapeseed. Herbicides can affect disease levels directly and indirectly by stressing host plants, influencing pathogens, and altering abiotic and biotic stress levels in the environment. The specific effects of herbicides on the dimorphic pathogen N. capsellae regarding hyphal growth, conidial germination rate, and the morphological transformation from multi-celled hyphae or conidia into numerous single-celled blastospores remain unknown. Hence, studies were performed on two agar media [malt extract agar (MEA) and water agar (WA)] to determine how atrazine and glyphosate, each applied at 1 g a.i. L⁻¹ or the commercial recommended concentrations of 10 and 7.8 g a.i. L⁻¹, respectively, affect these characteristics in four highly pathogenic isolates of N. capsellae. Across a 32-day assessment period, the hyphal growth of all four isolates subcultured individually on MEA or WA was significantly restricted by both concentrations of atrazine and glyphosate. For both atrazine and glyphosate, restriction of hyphal growth was much greater at the higher commercial recommended concentration. Glyphosate restricted hyphal growth more than atrazine for each comparative concentration. Using a mixture of all four isolates, a similar trend of suppression by atrazine or glyphosate occurred in relation to conidial germination and the morphological transformation from multi-celled hyphae or conidia into numerous single-celled blastospores. These new insights into how herbicides constrain hyphal growth, conidial germination, and morphological transformation suggest their potential as a control measure in herbicide-tolerant crops to limit the epidemic spread and development of not only N. capsellae in rapeseed but other dimorphic fungal pathogens as well.

Urban ecosystems are increasingly shaped by multiple environmental stressors, which may threaten both biodiversity and human well-being. We summarised the current knowledge on the ecological and social consequences of seven major urban pressures: air pollution, freshwater degradation, biological invasions, noise pollution, habitat fragmentation, soil pollution and climate crisis. Air and soil pollution, largely driven by traffic and industrial activities, compromises vegetation functions, reduces ecosystem services, and affects human health. Urban freshwater systems face contamination from stormwater runoff, wastewater, and microplastics, leading to biodiversity loss, altered ecosystem processes, and reduced water availability. Biological invasions, facilitated by human activities and habitat disturbances, reshape ecological communities, outcompete native species, and impose socio-economic costs, while management requires integrated monitoring and citizen engagement. Noise pollution disrupts animal communication, alters species distributions, and poses significant risks to human physical and mental health. Simultaneously, habitat fragmentation and loss reduce ecological connectivity, impair pollination and dispersal processes, and heighten extinction risks for both plants and animals. Collectively, these stressors interact synergistically, amplifying ecological degradation and exacerbating health and social inequalities in urban populations. The cumulative impacts highlight the need for systemic and adaptive approaches to urban planning that integrate biodiversity conservation, public health, and social equity. Nature-based solutions, ecological restoration, technological innovation, and participatory governance emerge as promising strategies to enhance urban resilience. Furthermore, fostering citizen science initiatives can strengthen monitoring capacity and create community ownership of sustainable urban environments. Addressing the combined pressures of urban environmental stressors is thus pivotal for building cities that are ecologically robust, socially inclusive, and capable of coping with the challenges of the climate crisis and global urbanization.

Tropospheric ozone (O₃) pollution is a major concern in urban environments because of its toxicity for both people and vegetation. This paper review provides an overview of atmospheric mechanisms, as well as the potential and best management practices of urban greening for reducing O₃ pollution in cities. Urban greening has often been proposed as a cost-effective solution to reduce O₃ pollution, but its effectiveness depends on careful species selection and integration with broader air quality management strategies. Ozone is a secondary pollutant and the volatile organic compounds emitted by vegetation (BVOCs) can play a prominent role in O₃ formation. A list of recommended and to-avoid species is given here to drive future planting at city scale. Planting low BVOC-emitting species and combining greening with reductions in anthropogenic emissions are key to maximizing benefits and minimizing unintended increases in O₃. Public and non-public institutions should carefully select plant species in consultation with expert scientists from the early stages, e.g., by considering local conditions and pollutant dynamics to design effective greening interventions. Collaborative planning among urban ecologists, atmospheric scientists, and municipalities is thus crucial to ensure that greening interventions contribute to overall air quality improvements rather than inadvertently enhancing O₃ formation. Such improvements will also translate into plant protection from O₃ stress. Therefore, future directions of research and policy integration to achieve healthier, O₃-resilient urban ecosystems are also provided.