Figure 1.

(A) Plant species can be represented by the proportion of biomass in leaves, roots, stems, and seeds (28). In low nutrient habitats, superior competitors have high biomass in root, low biomass in stem and seed, and moderate biomass in leaves. Such superior competitors stably coexist with species that are progressively poorer competitors, but better dispersers (25). (B) In a fertile habitat, plant height and thus stem biomass is a determinant of competitive ability for light. (C) A nutrient-poor region, experiencing high rates of nutrient deposition. The region of coexistence includes only a few of the species originally present in the nutrient-poor region. These species would be competitively dominant and displace all of the other species, but be subject to invasion by species in the vacant region enclosed by the solid curve. Because Percent Root + Percent Stem + Percent Seed + Percent Leaf = 100%, Percent Leaf is about 30% for all cases shown.