Dendrochronology and wood anatomy developed for decades as two independent scientific fields. It was only in the last decade that it was made clear that the dimension of time is the fourth dimension for both sciences and that it was demonstrated that wood anatomy and dendrochronology are perfect partners. The main aim of this book is to show the hidden ecological richness in stems and roots from trees, shrubs and herbs. It should encourage researchers to consider the anatomic microcosm of wood plants and use it as a retrospective source of information, solving problems related to ecophysiology, competition, site conditions, population biology, earth science, wood quality and even human history.