Walrasian equilibrium behavior in nature.

Area of Science:

• Ecology
• Mycology
• Biogeochemistry

Background:

• Land plants and mycorrhizal fungi (MF) form a widespread symbiotic relationship, essentially a biological market.
• MF acquire soil nutrients and exchange them with host plants for carbon, a fundamental ecological interaction.

Purpose of the Study:

• To quantify the trading behavior of arbuscular MF when exchanging phosphorus with host plant roots.
• To test the revealed preference hypothesis, an economic theory, within the context of this biological market.

Main Methods:

• Experimental quantification of arbuscular MF behavior in phosphorus trading.
• Inference of trade quantities under varied phosphorus resource scenarios across different MF patches.

Main Results:

• Observed MF trading behavior aligns with predictions of the revealed preference hypothesis.
• Quantified phosphorus and carbon exchange dynamics between MF and plant roots under controlled conditions.

Conclusions:

• The study provides empirical support for applying economic equilibrium models, specifically Walrasian equilibrium, to biological markets.
• Revealed preference principles effectively characterize mycorrhizal fungi's nutrient exchange strategies with plants.