Abstract: Forest as the dominant component of terrestrial ecosystems, hinge on internal nutrient cycling mechanisms to support individual plant development and the maintenance of ecosystem functions. Arbuscular mycorrhizae (AM) and ectomycorrhizae (ECM), the two most widespread mycorrhizal symbioses in forest ecosystems, playing pivotal roles in regulating nutrient cycling and sustaining functional stability along the “soil-plant-litter continuum”. Although numerous efforts have explored the effects of mycorrhizal types on key nutrient cycling processes in forests, these studies focus more on isolated process, with limited attention to the holistic nutrient cycling mediated by mycorrhizal interactions. This review synthesizes research from the past three decades to systematically examine the roles and underlying mechanisms through which AM and ECM-associated plants influence key processes across the internal nutrient cycling, including nutrient mineralization and mobilization, nutrient uptake by mycorrhizal-root systems, nutrient resorption from senescent organs, and nutrient return through litter decomposition. It further elucidates the self-sustaining nutrient dynamics of forest ecosystems dominated by different mycorrhizal types, aiming to provide insights into how nutrient cycling strategies shaped by mycorrhizal symbioses respond and adapt to forest management and global environmental change. Finally, we propose future research directions: (1) investigating the role of Common Mycorrhizal Networks (CMNs) in nutrient internal cycling under AM- versus ECM-dominated stands, while focusing on less-studied mycorrhizal types (e.g., dual-mycorrhizal plants, legumes with rhizobia-AM/ECM symbiosis) and Ericoid Mycorrhiza (ERM); (2) developing “mycorrhiza-site” matching models and mycorrhizal trait databases based on AM and ECM strategic differentiation, to optimize tree species selection in reforestation and afforestation across different site conditions; (3) assessing the buffering capacity of shifts in AM and ECM distributions on nutrient cycling under global change and (4) integrating long-term and multidimensional monitoring to unravel the co-evolutionary dynamics among mycorrhizal types, soil environments, and microbial communities driving nutrient cycling.

Key words: forest ecosystem, internal nutrient cycling, global change, arbuscular mycorrhizae, ectomycorrhizae