How rice land availability shapes diversification–specialisation gradients in Madagascar's clove landscapes

Understanding why agroforestry systems are more or less diversified in species is essential for sustaining livelihoods and ecological functions in perennial-crop landscapes. In eastern Madagascar, clove-based agroforestry dominates upland production systems, yet field structure varies markedly across short distances. Our objective was to clarify how landscape-scale rice production capacity influences agroforestry diversification–specialisation trajectories in clove-dominated landscapes. We combined tree-inventory data from 54 plots with landscape descriptors and a quantitative proxy of village-level rice self-sufficiency to analyse agroforestry composition across three neighbouring villages with contrasting access to irrigated lowlands. Four agroforestry system types—complex agroforests, diversified cash-oriented systems, clove-dominated systems and simple parklands—were identified through rule-based classification. Village-level access to irrigated lowlands was strongly associated with their distribution. In the valley with extensive irrigated lowlands, agroforestry systems remained highly diversified, integrating fruit, forest and cash-crop species. In intermediate landscapes, mixed configurations occurred. In upland areas where irrigated lowlands were scarce, clove became the main means of securing staple foods through market purchases, corresponding to simplified, clove-dominated systems. Contrary to expectations, within-village topography did not influence perennial species composition. Village-scale differentiation aligned with food-security constraints operating at the household level rather than fine-scale ecological sorting. These findings suggest that contemporary agroforestry configurations result from the interaction between historical trajectories—colonial coffee plantations, farmer-led clove expansion and post-independence enrichment practices—and present-day rice availability, which appears to filter how diversification or specialisation unfolds. Our results highlight that maintaining agroforestry diversity in clove-producing regions depends as much on securing stable rice production systems as on managing perennial-crop markets.