ABSTRACT Soil organic carbon (SOC) stabilisation in agricultural soils is governed by interactions between physical protection within aggregates and biochemical inputs derived from microbial activity, yet their relative importance remains poorly quantified in fruit tree‐based horticultural systems. This study evaluated SOC stabilisation mechanisms under four fruit tree species ( Pyrus communis , Prunus persica , Citrus reticulata and Psidium guajava ) and a barren control by integrating aggregate‐associated SOC, biochemical indicators and temperature sensitivity of carbon mineralisation. Across all systems, macroaggregates contained on average 12% higher SOC than microaggregates, with P. guajava macroaggregates exhibiting the highest SOC content (23.33 g kg −1 ). Cumulative SOC mineralisation at 35°C and 60 days was lowest under P. guajava in both macro‐and microaggregates (18.67 and 11.15 mg CO 2 g −1 , respectively), while barren soil showed the highest carbon loss. Polysaccharides and glomalin‐related soil proteins were significantly higher under P. guajava and P. persica and were positively associated with aggregate stability (mean weight diameter). Temperature sensitivity analysis indicated that P. guajava exhibited the highest Q 10 value (1.37) and the lowest activation energy (72.75 kJ mol −1 ), suggesting greater resistance of SOC pools to short‐term warming. A categorical integration of physical, biochemical and thermal indicators highlighted clear species‐specific differences in SOC stabilisation pathways. These findings indicate that fruit tree species selection strongly influences SOC stabilisation mechanisms in horticultural soils. Systems dominated by P. guajava and P. persica appear particularly effective in enhancing aggregate stability and SOC retention, underscoring their potential role in climate‐smart perennial agriculture.
Thangavel et al. (Thu,) studied this question.