Lawns play a key role in enhancing public spaces, preventing soil erosion, and acting as barriers against dust and sludge. In Brazil, Paspalum notatum is widely cultivated for its adaptability to the country's ecosystems and the availability of native ecotypes. However, soil salinization, a growing ecological concern, can limit lawn growth due to sodium and chloride ion toxicity. This study aimed to identify the most tolerant among five genotypes (Arua & iacute; and Tiriba cultivars, BRA 010006 and BRA 019178 accessions and the commercial species Axonopus fissifolius) subjected to salinity levels (0.5, 1.5, 3.0, 4.5, and 6.0 dS m(-1)). Analyzed variables included Na and Cl contents in plants, growth parameters (leaf and root dry mass and soil coverage), and morphological symptoms. No significant changes in leaf color or damage compromising aesthetics or functionality at salinity levels from 0.5 to 1.5 dS m(-1), with only occasional yellowing or minor scorch. Higher salinity led to leaf burn and yellowing, particularly in accession BRA 010006 and the control. Sodium and chloride contents, especially sodium, was higher in roots than leaves. Accession BRA 019178, followed by cultivars Arua & iacute; and Tiriba, demonstrated moderate tolerance, maintaining satisfactory soil coverage and dry mass across the tested salinity levels. These findings highlight the importance of selecting native turfgrasses with enhanced salt tolerance for landscaping applications in saline-prone areas.

Despite growing recognition of the role that cities have in global biogeochemical cycles, urban systems are among the least understood of all ecosystems. Urban grasslands are expanding rapidly along with urbanization, which is expected to increase at unprecedented rates in upcoming decades. The large and increasing area of urban grasslands and their impact on water and air quality justify the need for a better understanding of their biogeochemical cycles. There is also great uncertainty about the effect that climate change, especially changes in winter snow cover, will have on nutrient cycles in urban grasslands. We aimed to evaluate how reduced snow accumulation directly affects winter soil frost dynamics, and indirectly greenhouse gas fluxes and the processing of carbon (C) and nitrogen (N) during the subsequent growing season in northern urban grasslands. Both artificial and natural snow reduction increased winter soil frost, affecting winter microbial C and N processing, accelerating C and N cycles and increasing soil:atmosphere greenhouse gas exchange during the subsequent growing season. With lower snow accumulations that are predicted with climate change, we found decreases in N retention in these ecosystems, and increases in N2O and CO2 flux to the atmosphere, significantly increasing the global warming potential of urban grasslands. Our results suggest that the environmental impacts of these rapidly expanding ecosystems are likely to increase as climate change brings milder winters and more extensive soil frost.