Missing Maps is a humanitarian mapping project that maps vulnerable places in the developing world. Its outcomes are used to target aid in affected areas and to help achieve Sustainable Development Goals. A mapathon is an event in which a group of volunteers maps a defined location. The presented communication answers the following questions: What is the motivation of different contributors in the Missing Maps community in Czechia and Slovakia? How can a mapathon be set up to attract as many participants as possible? How exactly can the contributors to humanitarian mapping subjectively evaluate their contribution so far? A questionnaire about the motivation of contributors and the analysis of statistics from eighteen public mapathons in Brno (Czechia) were used as the primary research methods. The analysis of motivation found six strong motivators. Half of them concern altruism and half of them relate to the importance of the OpenStreetMap project and the mapping community. Analysis of the characteristics of 18 mapathons found that the month of the mapathon had a significant influence on the number of attendants. Statistical analysis confirmed a significant correlation between the number of edits and participants’ self-assessment. This means that humanitarian mappers evaluate their overall contribution very realistically. Analyses with an identical scope are planned for future years.

Central European forests suffered from severe, large-scale atmospheric depositions of sulfur and nitrogen due to coal-based energy production during the 20th century. High deposition of acid compounds distorted soil chemistry and had negative effects on forest physiology and growth. Since 1994, continuous data on atmospheric deposition and stream runoff fluxes have provided evidence of ecosystem recovery from acidification. In this study, we combined for the first time mass budget data (sulfur deposition and total dissolved inorganic nitrogen (DIN) export) from the GEOMON monitoring network of headwater catchments with annual trajectories of vegetation indices derived from Landsat remote sensing observations. Time series of selected vegetation indices was constructed from Landsat 5, 7, and 8 using Google Earth Engine. Linear regression between the field data and vegetation indices was analyzed using R software. Biogeochemical responses of the forested catchment to declining acid deposition (driven by SO₂ emission reduction) were consistent across all catchments covering various forest stands from different regions of the Czech Republic. Significant correlations were found with total sulfur depositions, suggesting that the forests are continuously and consistently prospering from reductions in acid deposition. Disturbance index (DI) was the only vegetation index that was well-related to changes in forest cover associated with salvage loggings (due to the forest decline) during the 1980s and 1990s. A significant relationship (R² = 0.82) was found between the change in DI and DIN export in stream water. Regrowth of young forests in these highly affected areas tracks the most pronounced changes in total DIN export, suggesting a prominent role of vegetation in nitrogen retention. With the Landsat-derived DI, we could map decennial changes in forest disturbances beyond the small scale of the catchments to the regional level (demonstrated here for two protected landscape areas). This analysis showed the peak in forest disturbances to have occurred around the mid-1990s, followed by forest recovery and regrowth. Despite the improvement in forest ecosystem functioning over the past three decades in mountainous areas, emerging threats connected to changing climate will shape forest development in the near future.