Anatomical adaptations to permanently changed environmental conditions

Abstract

All wood anatomy classification books describe the structure of so-called “normally grown” specimens. Nature, however, also produces a few giants, and many dwarfs. Here the question is raised to which degree local environmental factors modify the morphology and anatomy of stems of individual species. Exemplarily presented are the xylem structures of a few large (giants) and small individuals (dwarfs) of trees and herbs. Larger-thanaverage individuals have experienced mostly favorable growing conditions when they were young, and during their lifetime escaped the effects of extreme growth-limiting factors such as lack of nutrients, water or light, frost, or injury. In contrast, limiting and extreme factors negatively affected growth in small individuals. Giants are the winners, and dwarfs are the losers of competition.