Nutrient Recycling under Deciduous Plantations in the Tropics and Subtropics: Mechanisms, Dynamics and Management Implications

Abstract

Deciduous tree plantations in tropical and subtropical regions are important sources of timber, fuelwood and landscape restoration cover, yet their capacity to sustain productivity over successive rotations depends on nutrient recycling processes that remain unevenly documented. This critical narrative review synthesises evidence on four principal nutrient-recycling pathways under deciduous and seasonally deciduous plantation cover: litterfall and decomposition, foliar nutrient resorption, throughfall and stemflow, and fine-root turnover with associated nitrogen mineralisation. The evidence indicates that nutrient return in deciduous systems is strongly seasonal, with major aboveground inputs concentrated around leaf senescence and subsequent decomposition pulses after rainfall resumes. Species identity affects both litter quantity and litter chemical quality, so total litter mass alone is an inadequate indicator of nutrient return. Evidence for foliar resorption supports its role as an internal conservation mechanism, but does not justify a universal claim that deciduous species resorb nutrients more efficiently than evergreen species. Throughfall and stemflow are potentially important canopy-mediated nutrient pathways, particularly for potassium and base cations, but direct studies in tropical deciduous plantation canopies are scarce. Belowground evidence indicates substantial fine-root contributions to nutrient cycling, although estimates remain method-dependent and geographically concentrated. Teak monocultures have been associated with declines in nitrogen, phosphorus or organic matter accumulation in some South and Southeast Asian chronosequences, whereas evidence from Ghana and from some Eucalyptus systems shows more context-dependent outcomes. These inconsistencies suggest that nutrient decline is not an inevitable species-intrinsic effect, but reflects interactions among soil parent material, rainfall, stand age, harvesting intensity, litter removal, fire history and species composition. Sustainable management therefore requires site-specific strategies, including litter retention, slash conservation, mixed-species design, conservative harvest residue management and long-term rotation-scale nutrient monitoring.