Cladonia stellaris represents a rare relict boreal aspect of the Czech lichen flora. This reindeer lichen is one of the critically endangered lichen species of the Czech Republic and the main factors threatening its occurrence in our territory in the future include habitat disturbance and climate change. Between 2020 and 2023, monitoring of the status of the six known localities of this species in the Šumava National Park was carried out, during which ten permanent monitoring plots were established at these localities, where climate sensors recording temperature and relative humidity were placed. The state of each permanent monitored plots was photographed annually. In this contribution, we present the results of this monitoring after the first three years of its duration. The boulder screes at Turnerova chata, the former Hálkova chata and Buzošná represent the richest localities of C. stellaris in the Šumava NP and in the Czech Republic. A significant decline of C. stellaris was observed in two permanently monitored plots (more than 45% compared to the initial status), while in other plots the status can be assessed as stable or even an increase in cover was observed. Monitoring is planned for a total period of ten years. Key words: Bohemian Forest, conservation, monitoring, reindeer lichens, threatened lichens.