Ecosystem processes interact through trade-offs or legacy effects, yet it remains unclear whether absorption (Get), resorption (Save), and decomposition (Return) are linked to form a ‘Get-Save-Return (GSR)’ continuum and conform to the economics spectrum theory. Here, we tested this hypothesis by synchronously integrating root-nutrient absorption, leaf-nutrient resorption, and leaf-litter decomposition of 15 co-occurring subtropical tree species. There was an active trade-off between phosphorus absorption and resorption, which further caused a passive trade-off between phosphorus resorption and leaf-litter decomposition, indicating that a process-based continuum exists and runs on phosphorus economy. Following the leaf economics spectrum, the acquisitive-strategy species had greater absorption, lower resorption, and faster decomposition, while the conservative-strategy species presented the opposite pattern. The continuum emerged among ectomycorrhizal species rather than arbuscular mycorrhizal species, implying a critical control of mycorrhizal association. Our findings demonstrate the existence of the ‘GSR’ continuum and provide a framework for understanding the whole-plant nutrient economy.