Plant Biomass and Surface Area: A 3/4 Power Law Relationship

Because B is predicted to scale proportionally to total M, theory predicts that the surface areas over which resources are exchanged with the environment are proportional to the 3/4 power of the total plant biomass. This means that as plant biomass increases, the surface area available for resource exchange increases at a slower rate. This relationship is known as the 3/4 power law, and it has been observed in a wide variety of plants.