The fundamentals of belowground bud banks

Photo Credit

Courtesy figure drawn by Alena Bartušková

Figure showing below-ground bud-bearing organs. Buds can occur on roots or stems and in some cases leaf peripheries. Axillary and apical buds only occur on below-ground and above-ground stems and adventitious buds usually occur on roots.

Similar to a soil seed bank, buds can be stored in the soil over time to form a bud bank. These belowground bud banks serve as the primary source of aboveground regrowth each growing season and following disturbances such as fire, grazing, drought, and anthropogenic land use. Bud banks play important roles in polar, temperate, and tropical habitats around the world.  

For example, in perennial grasslands, over 99 percent of stems can come from belowground buds. Therefore, the bud bank is the main source of forage production supporting livestock and wildlife in these systems. As the contributions of bud banks to ecosystem function have been recently recognized, scientists and managers would benefit from a synthesis of the current knowledge of belowground bud banks.

We summarized the current knowledge of belowground bud banks and their role in maintaining plant population, community, and ecosystem function. To provide background on belowground bud bank traits and dynamics, the life history of a bud was traced from bud formation to bud outgrowth and the factors regulating bud bank dynamics were discussed. This provided a framework to identify and define bud bank traits and outline how these traits are affected by different types of disturbance. 

Key Findings

• Belowground bud banks serve two primary ecological functions: plant population renewal at the beginning of the growing season and plant regeneration following plant damage from disturbance.
• Bud bank dynamics (bud inputs, bud outputs, and bud dormancy) and the resources available to support bud outgrowth determine the recovery potential of a plant population or community following seasonal dormancy or disturbance.
• Bud bank traits can be used to compare plant species and communities and explain their differential response to disturbance.
• Bud banks have the potential to stabilize populations experiencing disturbance, affect invasion success, and alter above-ground species composition and productivity.