Landscape conservation and orchard management influence carob tree yield through changes in pollinator communities

Area of Science:

• Agricultural Science
• Ecology
• Entomology

Background:

• Global pollinator declines threaten agricultural productivity.
• Understanding landscape and management impacts on crop pollination is crucial for sustainable agriculture.
• Carob (Ceratonia siliqua) is a vital Mediterranean crop dependent on pollinators.

Purpose of the Study:

• To assess how landscape characteristics and orchard management influence pollinator communities and carob production.
• To identify strategies for enhancing carob crop production sustainably.

Main Methods:

• Field study of 20 carob orchards in Mallorca, Spain.
• Evaluation of landscape (habitat loss) and local management (farming system, male-to-female ratio).
• Analysis of pollinator visits, abundance, and crop yield (fruit, seed production, seed weight).

Main Results:

• Natural landcover increased wild bee and butterfly visits, while decreasing honeybee visits.
• Ecological orchards showed slightly higher pollinator abundance than conventional ones (not significant).
• Optimized male-to-female ratios (25-30% males) maximized total orchard production.
• Seed weight, a key economic factor, increased with wild pollinators and overall abundance but decreased with higher male-to-female ratios.

Conclusions:

• Preserving natural landscapes is key to supporting wild pollinators and enhancing carob seed weight.
• Optimizing orchard sex ratios can significantly improve overall carob production.
• Integrated management strategies combining landscape conservation and appropriate sex ratios are recommended for sustainable carob farming.