Tree-ring research, also known as dendrochronology, is a scientific method of dating and studying past events and environmental conditions by analyzing the growth rings in tree trunks. By studying the width, density, and chemical composition of tree rings, researchers can determine information such as the age of the tree, past climate conditions, and patterns of natural events like forest fires or volcanic eruptions. Tree-ring research can provide valuable insights into past environmental changes and help scientists understand the impact of human activities on ecosystems.