Jan Altman is a forest ecologist and environmental scientist affiliated with the Institute of Botany of the Czech Academy of Sciences in Průhonice and the Czech University of Life Sciences Prague, whose research focuses on understanding how climate change, disturbances, and ecological processes shape forest and plant ecosystems across global biomes. His work spans temperate, boreal, tropical, and alpine regions, integrating dendrochronology, plant functional ecology, forest dynamics, and remote sensing. Through extensive tree-ring analyses, he has revealed how droughts, warming, and extreme climatic events such as tropical cyclones influence tree growth, wood density, carbon storage, and long-term forest stability across Europe, North America, Asia, and Africa. His studies on Himalayan tree species, alpine cushion plants, and Afrotropical vegetation have provided critical insights into species-specific climate sensitivity and elevation-driven ecological limits. Jan Altman has also contributed to global assessments of forest disturbances, soil and understory temperature patterns, plant invasion dynamics, and biodiversity turnover, linking large-scale ecological patterns with fine-scale physiological responses. He frequently collaborates within international research networks, contributing to high-impact journals such as Science Advances, Nature Communications, Global Change Biology, Climate Dynamics, and Science of the Total Environment. In addition to climate-growth relationships, his work addresses forest homogenization, species coexistence, functional traits, and post-disturbance recovery processes. He has played a role in advancing the use of drone-borne imagery and medium-resolution satellite data for forest monitoring while critically evaluating their limitations. Alongside his research output of over a hundred scientific publications, he actively contributes to the scientific community as a peer reviewer for leading ecological and environmental journals. Overall, his research significantly advances understanding of how global change drivers interact with forest structure, plant growth dynamics, and ecosystem resilience, providing essential knowledge for sustainable forest management and biodiversity conservation under accelerating climate change.