This book aims to offer a detailed understanding of the ecological principles governing forest ecosystems. It covers forest structure and function, biodiversity, and the roles of forests in global biogeochemical cycles. The book also addresses the impacts of human activities, climate change, and conservation strategies on forest ecosystems. Designed for undergraduate and graduate students, it combines theoretical frameworks with field-based research examples. Supplementary materials include case studies, data analysis exercises, and access to online resources for further exploration.