Forest ecosystems exist at the interface between the land and the atmosphere. Understanding the properties of this planetary boundary layer is very important for a number of related disciplines. This book presents an overview of topics that are of significance at this interface, starting at the scale of intra-leaf organelles, ranging to higher levels of organisation such as communities and ecosystems. It covers topics such as stomatal functioning, large scale processes, radiation modelling, forest meteorology and carbon sequestration. Based on proceedings of a conference to mark the retirement of Professor Paul Jarvis from the University of Edinburgh, the book contains contributions from leading international scientists. It will be of significant interest to researchers in forestry, ecology, environmental sciences and natural resources.