Rising air temperatures due to global warming will likely become a key abiotic stressor that woody plants will have to cope with. While numerous studies have examined individual stressors, plants typically suffer from combinations of stressors in their natural habitats. In recent years, combined abiotic stresses have become a particularly serious consequence of climate change. Drought-induced moisture deficits, coupled with rising air temperatures, have been recognized as among the most important triggers of tree mortality worldwide. This study was the first to examine dark-coniferous Siberian pine (Pinus sibirica Du Tour) stands in the eastern part of the Republic of Tuva using a rapid analytical method – thermogravimetry. Our results show that the earliest stage of stress diagnosis is possible in the "weakened trees" life stage, with 11-25% defoliation, minor changes in needle color, and isolated lesions. At this stage, the relative lignin content decreases and the relative cellulose content increases. This fact opens the possibility of identifying trees in critical condition. Furthermore, increasing relative lignin content and decreasing relative cellulose content can serve as a marker for determining a critical phase. Similarly, a simultaneous decrease in cellulose activation energy values is a marker of structural degradation. These findings highlight the need to reconsider traditional approaches to forest management in the face of anthropogenic climate change and develop new strategies for preserving the biodiversity of boreal ecosystems. A consistent study of the physicochemical processes in dark coniferous stands is essential for the implementation of timely risk management measures in forestry.
Zhila et al. (Fri,) studied this question.