Schnoor, ChristinaRieck, Kristoffer BargisenBeech, EmilyRivers, MalinKusnick, JakobJänicke, StefanDutta, SoumyaFeige, KathrinRink, KarstenZeckzer, Dirk2023-06-102023-06-102023978-3-03868-223-3https://doi.org/10.2312/envirvis.20231111https://diglib.eg.org:443/handle/10.2312/envirvis20231111Trees are important to ecosystems around the world, and therefore it is vital to know which species are in particular need of conservation. The GlobalTree Portal primarily focuses on threat assessments at the global level, but nation-level investigations of threat assessments are not yet supported. Regional or national assessments are also displayed, even if the species was not evaluated in a country. This paper presents a visualization framework that enables domain experts to analyze national assessments inspired by the GlobalTree Portal. This visualization first provides a global overview of nation-level threat assessment efforts by highlighting those with many national assessments on a choropleth map. For a selected country, the experts can inspect how the tree species assessments are distributed across BGCI's threat level categories Not Evaluated, Data Deficient, Not Threatened, Possibly Threatened, Threatened, and Extinct. The core component is a tree map visualization that displays the genera and the species within the selected country. These are color-coded according to the BGCI threat level, and thus, provide a quick overview of nation-level threat assessments at species and genus levels. The system was developed in close collaboration with biologists from BGCI, who evaluated the visualizations on a regular basis to fit their needs. The results certify the value of our solution for gaining quantitative insights about threat assessments on a national level, and BGCI researchers included the system in their work routines to impact decision making processes on national conservation actions.Attribution 4.0 International License10.2312/envirvis.2023111193-986 pages