Recovering the Metabolic, Self-Thinning, and Constant Final Yield Rules in Mono-Specific Stands

作者：Assaad Mrad, Stefano Manzoni, Ram Oren, Giulia Vico, Magnus Lindh, Gabriel G. Katul · 发表于：Frontiers in Forests and Global Change · 年份：2020 · DOI：10.3389/ffgc.2020.00062 · 被引用次数：41 · 研究领域：Bioenergy crop production and management、Forest Biomass Utilization and Management、Forest ecology and management

Competition among plants of the same species often results in power-law relations between measures of crowding, such as plant density, and average size, such as individual biomass. Yoda’s self-thinning rule, the constant final yield rule, and metabolic scaling, all link individual plant biomass to plant density and are widely applied in crop, forest, and ecosystem management. These dictate how plant biomass increases with decreasing plant density following a given power-law exponent and a constant of proportionality. While the exponent has been proposed to be universal and thus independent of species, age, and environmental, and edaphic conditions, different theoretical mechanisms yield absolute values ranging from less than 1 to nearly 2. Here, eight hypothetical mechanisms linking the exponent to constraints imposed on plant competition are featured and contrasted. Using dimensional considerations applied to plants growing isometrically, the predicted exponent is -3/2 (Yoda's rule). Other theories based on metabolic arguments and network transport predict an exponent of -4/3. These rules, which describe stand dynamics over time, differ from the 'rule of constant final yield' that predicts an exponent of -1 between the initial planting density and the final yield attained across stands. The latter can be recovered from statistical arguments applied at the time scale in which the site carrying capacity is approached. Numerical models of plant competition produce plant biomass...