Compartmentalized Homeostasis Drives High Bamboo Forest Productivity under Nutrient Imbalance

Area of Science:

• Plant ecophysiology
• Ecosystem stoichiometry
• Nutrient cycling

Background:

• Stoichiometric homeostasis is crucial for plant fitness amid soil nutrient variability.
• Traditionally viewed as static, homeostasis is now understood as a conditionally flexible trait, but empirical evidence is limited.

Purpose of the Study:

• To investigate the stoichiometric homeostasis strategies of Moso bamboo (Phyllostachys edulis) under varying soil nutrient conditions.
• To determine if Moso bamboo exhibits a flexible, compartmentalized nutrient regulation strategy.
• To assess the impact of this strategy on plant productivity and its implications for ecosystem function.

Main Methods:

• Large-scale field investigations across diverse geographical and soil nutrient gradients.
• Experimental nutrient (nitrogen and phosphorus) additions.
• Data synthesis and comparative analysis with co-occurring tree species.

Main Results:

• Moso bamboo exhibits a unique compartmentalized homeostasis strategy, decoupling nitrogen and phosphorus regulation across tissues.
• Strict nitrogen:phosphorus (N:P) homeostasis is maintained in leaves, while woody tissues act as flexible phosphorus reservoirs.
• This strategy results in lower leaf N:P variability compared to 75 out of 91 co-occurring tree species, contributing to higher annual productivity.

Conclusions:

• Moso bamboo's flexible, compartmentalized homeostasis resolves growth-stability conflicts, reconciling classical homeostasis views with plasticity.
• This mechanism is a critical factor for Moso bamboo's high productivity and adaptability.
• Understanding this strategy advances predictions of ecosystem responses to global change, including nutrient cycling and carbon sequestration.