Droughts accompanied by high temperatures are becoming increasingly frequent across Europe and globally. Both individual trees and entire forest ecosystems are exposed to drought stress, with prolonged drought periods leading to increased tree mortality. Therefore, continuous monitoring, data collection, and analysis of tree mortality are essential prerequisites for understanding the complex interactions between climate and trees. This study examined the effects of short-term and prolonged (multi-year) droughts on the mortality of individual trees and forests in Serbia. The analysis was based on datasets from our previous research on the influence of drought and drought duration on individual tree mortality in Serbian forest ecosystems, supplemented with new data collected through the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests). Additionally, we incorporated data from the public enterprise (PE) “Srbijašume”, which manages forests in Central Serbia, focusing on random yields resulting from natural disasters (droughts). These data enabled a comparative assessment of the findings on increased mortality and drought impact at both the individual tree level and the stand level. This study identifies key similarities and differences in tree mortality trends based on drought duration and examines their correlations within the same time frame (2004–2023). By analysing climatic conditions across Serbia, we provide evidence of the interaction between drought periods and increased forest mortality, which we further confirmed by calculating the Standardized Precipitation Evapotranspiration Index (SPEI). We also address the tree species that were most sensitive to the effects of drought. Our findings indicate that prolonged (multi-year) droughts, accompanied by high temperatures, have significantly contributed to increased tree mortality over the past decade. Successive multi-year droughts pose a substantial threat to both individual trees and entire forests, producing more severe and persistent responses compared to those caused by single-year droughts, which forests and individual trees are generally more capable of tolerating. Moreover, due to prolonged drought stress, trees weaken, leading to delayed mortality that may manifest several years after the initial drought event. The observed increase in tree mortality has been found to correlate with rising temperatures and the growing frequency of prolonged droughts over the past decade. Especially, intense droughts in the growing season (April–September) have a very negative impact on forests.

The aim of this paper is to analyze virgin beech forest stands, both those with a certain protection status and those without a legal or planned protection status that are managed by applying regular management methods. In addition, the active and passive conservation approaches to virgin beech forests are analyzed and concerns about biodiversity loss and causal links in the relationships between forest planning, management, governance and their functions are partially addressed. This paper presents the results of a study on virgin forest stands, with a special focus on beech stands, the most common tree species in the Republic of Serbia. On the one hand, these stands are generally under a high degree of protection with the status of a general or strict nature reserve, while on the other, they are also located in stands where regular management is applied. Regardless of this, according to all structural parameters, the stands investigated in this study clearly belong to the group of virgin forest stands. The values of parameters in all the stands studied, both those under several-decades-long protection and stands subjected to regular forest management, indicate a high production potential. The issue of protection approach is discussed, from passive protection on the one hand (conservation approach) to active protection, which allows the implementation of various silvicultural measures with limited intensity and periodicity. The paper concludes that the conservation approach to protection does not automatically imply that the existing state of forests is preserved, while the proactive approach to protection can contribute to its preservation and improvement.