היומן של grazing

Several months ago, I thought it would be entertaining to use iNaturalist observations for an experiment. I wanted to devise a project based on plants that preferred to live in acidic soils. I went on the USDA Plant Database (https://plants.usda.gov/home) and searched for species that can tolerate conditions with a pH level of 6 and below. I then created a project (https://www.inaturalist.org/projects/organisms-which-prefer-ph-levels-between-0-6) based on these species. The map itself generally follows acidic soil trends throughout the globe. The BONAP (The Biota of North American Program) map (http://www.bonap.org/2008_Soil/SoilTypesRelatedMaps.html) of acidic soils around the United States reflects the trends seen in the observations except around Michigan, Indiana, Ohio, Wisconsin, and Illinois. I am unsure of why this is so far. In Europe, it also follows a clear trend. Although, I think I am missing some European species. Spain and Eastern Europe show this trend well. Some sources of error in the project are a scarcity of observations in some regions, human interference, GPS coordinate, human error, etc. It is astonishing to see how you can use iNaturalist to observe trends like these.