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.

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.

[5] The barrel can only hold water up to the level of the shortest slat and, likewise, plants can only grow at a rate allowed by the limiting resource.

Plants grown in low light conditions have been shown to allocate more biomass to shoots (mainly leaves).

[6] If sunlight is limiting the plant increases growth to the shoot and decreases the energy partitioned to the roots because the lower rates of photosynthesis lessen need for water and mineral nutrients.

Plant cells have increased carbon to nitrogen ratios when CO2 concentrations are higher, which decreases levels of decomposition.

[10] This altered structure functions to reduce surface area of the roots and the effects of toxic nutrients while also conserving biomass for parts of the plant where growth would be more beneficial.

Interspecific and intraspecific competition can cause a decrease in the available resources for an individual plant and alter how it partitions biomass.

[16] Many biomass partitioning studies consist of manipulative experiments that increase or reduce levels of growth-limiting resources and observe the effects.

Often-times these studies use potted plants grown in a greenhouse to measure effects of density, excess nutrients, low light etc.

The methods and measurements for determining biomass partitioning can be quite difficult due to the weight and volume of larger plants.