Contrasting Phenological Patterns and Reproductive Strategies in Closely Related Monoecious Fig Tree Species.

Area of Science:

• Ecology
• Evolutionary Biology
• Botany

Background:

• Mutualistic interactions are crucial for predicting species' responses to environmental shifts.
• Fig trees ( *Ficus* spp.) and their pollinating wasps engage in a highly specific mutualism vital for ecosystem stability.

Purpose of the Study:

• To investigate phenological patterns and reproductive strategies of two related fig tree species, *Ficus citrifolia* and *Ficus eximia*.
• To understand how mutualistic interactions shape fig tree reproductive success and genetic structure.

Main Methods:

• Long-term weekly monitoring of 120 fig trees (*F. citrifolia* and *F. eximia*) over five years (2006-2011).
• Analysis of flowering patterns, reproductive output (flowers, seeds), and pollinator dynamics.
• Comparative study in a tropical region of Brazil near the southern edge.

Main Results:

• Contrasting phenological patterns: *F. citrifolia* showed an annual pattern (1.4 episodes/year), while *F. eximia* exhibited a supra-annual pattern (0.5 episodes/year).
• *F. eximia* produced more pistillate flowers, seeds, and wasps per fig, suggesting adaptation to low population density.
• Fig wasps significantly influenced fig development, ripening, and the stability of the mutualism.

Conclusions:

• Distinct phenological and reproductive strategies in closely related fig species highlight adaptive divergence.
• The fig wasp's role is critical in mediating fig tree reproductive success and population dynamics.
• Understanding these mutualistic dynamics is essential for conservation and predicting ecosystem responses to environmental change.