Biomass partitioning

Biomass partitioning is the process by which plants divide their energy among their leaves, stems, roots, and reproductive parts. These four main components of the plant have important morphological roles: leaves take in CO₂ and energy from the sun to create carbon compounds, stems grow above competitors to reach sunlight, roots absorb water and mineral nutrients from the soil while anchoring the plant, and reproductive parts facilitate the continuation of species. Plants partition biomass in response to limits or excesses in resources like sunlight, carbon dioxide, mineral nutrients, and water and growth is regulated by a constant balance between the partitioning of biomass between plant parts. An equilibrium between root and shoot growth occurs because roots need carbon compounds from photosynthesis in the shoot and shoots need nitrogen absorbed from the soil by roots.^[1] Allocation of biomass is put towards the limit to growth; a limit below ground will focus biomass to the roots and a limit above ground will favor more growth in the shoot.^[2]

Plants photosynthesize to create carbon compounds for growth and energy storage. Sugars created through photosynthesis are then transported by phloem using the pressure flow system and are used for growth or stored for later use. Biomass partitioning causes this sugar to be divided in a way that maximizes growth, provides the most fitness, and allows for successful reproduction. Plant hormones play a large part in biomass partitioning since they affect differentiation and growth of cells and tissues by changing the expression of genes and altering morphology.^[3] By responding to environmental stimuli and partitioning biomass accordingly, plants are better able to take in resources from their environmental and maximize growth.