Urban Scaling of Health Outcomes: a Scoping Review.

Urban scaling is a framework that describes how city-level characteristics scale with variations in city size. This scoping review mapped the existing evidence on the urban scaling of health outcomes to identify gaps and inform future research. Using a structured search strategy, we identified and reviewed a total of 102 studies, a majority set in high-income countries using diverse city definitions. We found several historical studies that examined the dynamic relationships between city size and mortality occurring during the nineteenth and early twentieth centuries. In more recent years, we documented heterogeneity in the relation between city size and health. Measles and influenza are influenced by city size in conjunction with other factors like geographic proximity, while STIs, HIV, and dengue tend to occur more frequently in larger cities. NCDs showed a heterogeneous pattern that depends on the specific outcome and context. Homicides and other crimes are more common in larger cities, suicides are more common in smaller cities, and traffic-related injuries show a less clear pattern that differs by context and type of injury. Future research should aim to understand the consequences of urban growth on health outcomes in low- and middle-income countries, capitalize on longitudinal designs, systematically adjust for covariates, and examine the implications of using different city definitions

General destabilizing effects of eutrophication on grassland productivity at multiple spatial scales

Abstract Eutrophication is a widespread environmental change that usually reduces the stabilizing effect of plant diversity on productivity in local communities. Whether this effect is scale dependent remains to be elucidated. Here, we determine the relationship between plant diversity and temporal stability of productivity for 243 plant communities from 42 grasslands across the globe and quantify the effect of chronic fertilization on these relationships. Unfertilized local communities with more plant species exhibit greater asynchronous dynamics among species in response to natural environmental fluctuations, resulting in greater local stability (alpha stability). Moreover, neighborhood communities that have greater spatial variation in plant species composition within sites (higher beta diversity) have greater spatial asynchrony of productivity among communities, resulting in greater stability at the larger scale (gamma stability). Importantly, fertilization consistently weakens the contribution of plant diversity to both of these stabilizing mechanisms, thus diminishing the positive effect of biodiversity on stability at differing spatial scales. Our findings suggest that preserving grassland functional stability requires conservation of plant diversity within and among ecological communities

Author Correction: General destabilizing effects of eutrophication on grassland productivity at multiple spatial scales (Nature Communications, (2020), 11, 1, (5375), 10.1038/s41467-020-19252-4)

The original version of this Article contained an error in the author affiliations. The affiliation of Martin Schütz with Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zuercherstrasse 111, 8903 Birmensdorf, Switzerland was inadvertently omitted. Martin Schütz was incorrectly associated with Department of Forest Resources, University of Minnesota, Saint Paul, MN, US. This has now been corrected in both the PDF and HTML versions of the Article

Author Correction: General destabilizing effects of eutrophication on grassland productivity at multiple spatial scales (Nature Communications, (2020), 11, 1, (5375), 10.1038/s41467-020-19252-4)

The original version of this Article contained an error in the author affiliations. The affiliation of Martin Schütz with Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zuercherstrasse 111, 8903 Birmensdorf, Switzerland was inadvertently omitted. Martin Schütz was incorrectly associated with Department of Forest Resources, University of Minnesota, Saint Paul, MN, US. This has now been corrected in both the PDF and HTML versions of the Article