Safe drinking water access is a human right, but data on safely managed drinking water services (SMDWS) is lacking for more than half of the global population. We estimate SMDWS use in 135 low- and middle-income countries (LMICs) at subnational levels with a geospatial modeling approach, combining existing household survey data with available global geospatial datasets. We estimate that only one in three people used SMDWS in LMICs in 2020 and identified fecal contamination as the primary limiting factor affecting almost half of the population of LMICs. Our results are relevant for raising awareness about the challenges and limitations of current global monitoring approaches and demonstrating how globally available geospatial data can be leveraged to fill data gaps and identify priority areas in LMICs.

Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species^1,2. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies^3,4. Here, leveraging global tree databases^5–7, we explore how the phylogenetic and functional diversity of native tree communities, human pressure and the environment influence the establishment of non-native tree species and the subsequent invasion severity. We find that anthropogenic factors are key to predicting whether a location is invaded, but that invasion severity is underpinned by native diversity, with higher diversity predicting lower invasion severity. Temperature and precipitation emerge as strong predictors of invasion strategy, with non-native species invading successfully when they are similar to the native community in cold or dry extremes. Yet, despite the influence of these ecological forces in determining invasion strategy, we find evidence that these patterns can be obscured by human activity, with lower ecological signal in areas with higher proximity to shipping ports. Our global perspective of non-native tree invasion highlights that human drivers influence non-native tree presence, and that native phylogenetic and functional diversity have a critical role in the establishment and spread of subsequent invasions.

Mycorrhizal fungi are ecosystem engineers that sustain plant life and help regulate Earth's biogeochemical cycles^1-3. However, in contrast to plants and animals, the global distribution of mycorrhizal fungal biodiversity is largely unknown, which limits our ability to monitor and protect key underground ecosystems^4,5. Here we trained machine-learning algorithms on a global dataset of 25,000 geolocated soil samples comprising >2.8 billion fungal DNA sequences. We predicted arbuscular mycorrhizal and ectomycorrhizal fungal richness and rarity across terrestrial ecosystems. On the basis of these predictions, we generated high-resolution, global-scale maps and identified key reservoirs of highly diverse and endemic mycorrhizal communities. Intersecting protected areas with mycorrhizal hotspots indicated that less than 10% of predicted mycorrhizal richness hotspots currently exist in protected areas. Our results describe a largely hidden component of Earth's underground ecosystems and can help identify conservation priorities, set monitoring benchmarks and create specific restoration plans and land-management strategies.

Habitat fragmentation, in which contiguous forests are broken into smaller, isolated patches, threatens biodiversity by disrupting species movement, shrinking populations, and altering ecosystem dynamics. Past assessments suggested declining global fragmentation, but they relied on structure-based metrics that overlook ecological connectivity. We analyzed global forest fragmentation from 2000 to 2020 using complementary metrics that captured patch connectivity, aggregation, and structure. Connectivity-based metrics revealed that 51 to 67% of forests globally—and 58 to 80% of tropical forests—became more fragmented, which is nearly twice the rate suggested by traditional structure-focused methods (30 to 35%). Aggregation-focused metrics confirmed increases in 57 to 83% of forests. Human activities such as agriculture and logging drive this change. Yet protected tropical areas saw up to an 82% reduction in fragmentation, underscoring the potential of targeted conservation.

One mechanism proposed to explain high species diversity in tropical systems is strong negative conspecific density dependence (CDD), which reduces recruitment of juveniles in proximity to conspecific adult plants. Although evidence shows that plant-specific soil pathogens can drive negative CDD, trees also form key mutualisms with mycorrhizal fungi, which may counteract these effects. Across 43 large-scale forest plots worldwide, we tested whether ectomycorrhizal tree species exhibit weaker negative CDD than arbuscular mycorrhizal tree species. We further tested for conmycorrhizal density dependence (CMDD) to test for benefit from shared mutualists. We found that the strength of CDD varies systematically with mycorrhizal type, with ectomycorrhizal tree species exhibiting higher sapling densities with increasing adult densities than arbuscular mycorrhizal tree species. Moreover, we found evidence of positive CMDD for tree species of both mycorrhizal types. Collectively, these findings indicate that mycorrhizal interactions likely play a foundational role in global forest diversity patterns and structure.