Disappearing plants: why they hide and how they return.

Area of Science:

• Plant biology
• Ecology
• Life-history strategies

Background:

• Prolonged dormancy is a common plant life-history stage where mature plants delay resprouting for one or more seasons.
• The underlying causes and ecological consequences of prolonged dormancy remain largely uninvestigated.
• Understanding resource allocation during dormancy is crucial for plant survival and population dynamics.

Purpose of the Study:

• To determine if stored resources are linked to the decision to enter prolonged dormancy.
• To investigate the resource expenditure associated with remaining dormant throughout the growing season.
• To explore the role of nonstructural carbohydrates (NSC) in plant dormancy.

Main Methods:

• Measuring stored nonstructural carbohydrates (NSC) at the start and end of the growing season in *Astragalus scaphoides*.
• Comparing NSC concentrations between dormant and actively growing (emergent) plants.
• Analyzing resource dynamics and potential carbon remobilization in dormant plants.

Main Results:

• Dormant plants exhibited lower initial concentrations of stored NSC compared to emergent plants.
• Dormant plants accumulated NSC during the growing season, similar to actively growing plants.
• This NSC gain in dormant plants is likely attributed to the remobilization of structural carbon.

Conclusions:

• Low stored NSC levels are associated with the strategy of remaining belowground in prolonged dormancy.
• Remobilization of structural carbon may provide the necessary resources for dormant plants to emerge in subsequent seasons.
• Plant resource status can be modulated independently of direct assimilation, emphasizing the importance of stored reserves in environmental responses.