Abstract

The study of root structure and functioning is centuries old (Hales 1727, reprinted 1961). While great progress has been made (e.g., Brouwer et al. 1981), our knowledge is limited by the difficulties in studying roots in situ. These limitations color our perception of plants. A typical layperson knows that forests can grow 50−100 m in height, but rarely recognizes that root systems can grow to similar depths (Canadell et al. 1996). The individual may also never consider the functional consequences of roots that typically spread well beyond the canopy line of most plants (e.g., Lyford and Wilson 1964). Just as there is a quiet bias in maps of the world that consistently present the northern hemisphere ‘‘on top,’’ our perception of plants would change if they were drawn ‘‘upside-down’’—roots on top and shoots underneath. A small shrub such as Prosopis glandulosa would suddenly appear as majestic as a tree, and many trees would suddenly seem shrubby. The bias of human perception shadows our view of the plant world.