# Habitat Loss and Other Threats to the Survival of _Parnasius apollo_ ([PERSON], 1758) in Serbia
## 5 Conclusions  
This study provides robust evidence that the local extinction of _Parnassius apollo_ in Serbia is predominantly driven by habitat transformation following the cessation of traditional grazing practices. Temporal analysis of vegetation structure (2015-2024) shows that extant populations are associated with ecologically stable habitats, characterized by consistently high shrub and tree cover (>80%), moderate grass presence (<15%), and minimal bare soil exposure. In contrast, historically occupied sites such as Mount Stol and Bele Stene exhibit elevated levels of exposed soil, variable grass coverage, and progressive shrub encroachment--typical of unregulated ecological succession. These structural changes coincide with the disappearance of _Sedum album_, the species' obligate larval host plant. Fifteen years of remote sensing data reveal significant ecological stress in habitats without _P. apollo_ populations. Pronounced declines in key vegetation indices--LAI, FPAR, and GPP--were detected at sites such as Brzece and Bucje, correlating with increased land surface temperatures (LST), elevated potential evapotranspiration (PET), and decreased temperature condition index (TCI). These patterns reflect compound heat and drought stress, negatively impacting both plant physiology and larval development. The wildfire event on Mount Stol in August 2024 further exacerbated habitat degradation. Spectral indices (BAI, NBR, NBR2) confirmed extensive vegetation loss and spatially heterogeneous burn severity, compounding existing ecological pressures and further reducing the potential for natural habitat regeneration or host plant recolonization. The findings clearly indicate that habitat degradation is not attributable to a single driver, but results from the cumulative effects of multiple and potentially interacting stressors--successful overgrowth, climate extremes, heavy metal contamination, and wildfire--intensified by the abandonment of traditional land-use regimes results from the combined effects of multiple stressors--successful overgrowth, climate extremes, metal contamination, and wildfire--all intensified by the abandonment of traditional land-use regimes. Without immediate and integrated intervention, the remaining _P. apollo_ populations are at high risk of following the same extinction trajectory. To mitigate further loss and facilitate species recovery, we recommend that conservation actions prioritize the following:  
* Reintroduction of extensive grazing to restore and maintain open habitat mosaics;
* Active suppression of successional overgrowth to support the persistence of _Sedum album_;
* Continuous remote monitoring of thermal and hydrological stress using satellite-derived indices;
* Strategic fire prevention and management in ecologically sensitive areas. Our findings contribute to the growing body of evidence on how anthropogenic landscapes--or 'anthromes'--reshape ecological conditions and drive local extinctions of insect species, such as _Parnassius apollo_, underscoring the need to integrate land-use history into conservation planning. Conservation strategies must integrate ecological data with adaptive land-use management. Safeguarding _P. apollo_ extends beyond species preservation--it entails the protection and revitalization of traditional cultural landscapes essential to regional biodiversity. A comprehensive approach that combines satellite monitoring, field-based assessments, habitat restoration, and local stakeholder engagement is essential to halt and reverse the decline of this emblematic mountain butterfly. Conceptualization, D.V.S. ; methodology, D.V.S. and V.V. ; software, V.V. ; validation, D.R. and S.O. ; formal analysis, S.O. and J.I. ; investigation, D.V.S. and V.V. ; resources, S.O. ; data curation, V.V. ; writing--original draft preparation, D.V.S., V.V. and J.I. ; writing--review andediting, J.I., D.R. and S.O. ; visualization, V.V. ; supervision, D.R. : funding acquisition, S.O. All authors have read and agreed to the published version of the manuscript.