Literature review
We searched the Web of Science for studies plotting the relationship between the abundance of an organism and an environmental factor at large geographical scales. We used the following terms: (Abundan* OR ”population size” OR ”population trend” OR density) AND (biogeography OR Macroecology OR “large extent” OR “large scale”) on November 25th, 2020. Then, we selected literature from ecology and biogeography journals together with the multidisciplinary journal Nature (see the list of journals in Appendix S1), returning 4,700 articles (Fig 2A). From those, we conducted a title-based filtering that resulted in 744 publications (~18% of initial articles). Then, we reviewed the articles’ main text in search for at least one plot relating the abundance of an organism (or an equivalent measure, such as population density) against a continuous environmental predictor. For those that showed the data points in the plot, we visually classified the shape of the abundance-environment relationship as line-shaped, polygon-shaped, or unclear – in cases where it was not possible to clearly identify the point cloud shape due to low sample sizes or representation means. We also identified the statistical method used to estimate the relationship and if there was any mention to the LoM. Lastly, we recorded the taxonomic group, the habitat, and the geographical region of study.