关键词: 碳磷交换效率, 磷吸收利用, 地下碳分配, 菌根真菌, 根系分泌物

Abstract: Phosphorus (P) represents a critical limiting nutrient that modulates forest ecosystem productivity, and widespread soil P limitation has been documented across forest ecosystems distributed in various climatic zones. In tropical and subtropical forests, severe mineral weathering and leaching drive substantial P depletion, while in temperate forests, P is primarily adsorbed onto calcium-bearing minerals and occurs as poorly soluble, low-bioavailability fractions. The partitioning of photosynthetic carbon to belowground root systems forms a crucial material foundation for the mobilization and acquisition of soil P, and this carbon–phosphorus exchange fundamentally shapes the structure and function of forest ecosystems. Nevertheless, current studies still lack a systematic elucidation of the coupling mechanisms linking root carbon inputs and P acquisition, as well as the phosphorus-deficiency adaptation strategies adopted by different tree species. In this review, we systematically synthesize recent research advances on carbon–phosphorus exchange between tree roots and soil, with a focus on the coordinated regulatory mechanisms underlying belowground carbon allocation, plant P acquisition, and the efficiency of root-soil carbon–phosphorus exchange. Furthermore, we propose five directions for future research in this field: (1) expanding the scope of research subjects to clarify variations in phosphorus adaptation mechanisms across different tree species; (2) optimizing methodological systems and constructing an integrated analytical framework for P cycling research across scales from microscale to macroscale; (3) exploring multi-factor interactive effects to reveal the response patterns of forest carbon–phosphorus allocation and utilization under climate change; (4) resolving molecular regulatory pathways to clarify the signaling mechanisms of tree–microbe synergistic responses to P limitation; (5) strengthening long-term monitoring and model simulation to provide theoretical support for the adaptive management of phosphorus-limited forest ecosystems.

Key words: carbon-phosphorus exchange efficiency, phosphorus acquisition and utilization, belowground carbon allocation, mycorrhizal fungi, root exudates