The distinction between biotic variables, such as pollinators, pathogens, and competitors, and abiotic variables, such as temperature, pH, and humidity, is so basic to biology that it is routinely invoked in everything from painstaking ecological studies to basic textbooks. For all its pervasiveness, there are good reasons to renounce the biotic-abiotic distinction in daily biology. For one, the distinction is hard to make in practice because virtually all “abiotic” variables are profoundly affected by organisms. Even if it were possible, in most cases the distinction adds nothing and at worst makes communication more difficult. Best of all, overcoming the distinction leads to insights regarding niche construction, extended inheritance, and even redefinition of “evolution.”

¾-power scaling between metabolic rate and body mass is regarded as near-universal across organisms. However, there are compelling reasons to question ¾-power scaling in woody plants, where metabolic rate≈leaf area. This leaf area must provide carbon to the metabolically active sapwood volume (V MASW). V MASW is necessarily a much smaller volume than total wood volume, meaning that scaling of total leaf area LA tot with V MASW should be >¾. Within populations of a species, variants in which V MASW increases per unit leaf area with height growth (e.g. ¾ scaling) would have proportionally less carbon for growth and reproduction as they grow taller. Therefore, selection should favor individuals in which, as they grow taller, leaf area scales isometrically with V MASW. Using tetrazolium staining, we measured total V MASW and total leaf area across 22 individuals of Ricinus communis and confirmed that leaf area scales isometrically with V MASW, and that V MASW is much smaller than total sapwood volume. . With the potential of the LA tot-V MASW relationship to shape factors as diverse as the crown area-stem diameter relationship, conduit diameter scaling, reproductive output, and drought-induced mortality, our work suggests that the notion that sapwood increases per unit leaf area with height growth requires revision.