Mistletoe Viscum coloratum maintains a stable mutualistic network in temperate forest by strategic seed provisioning to avian dispersers

Mutualistic interactions between plants and their seed dispersers are essential for maintaining global biodiversity and ecosystem functions. Mistletoe ( Viscum coloratum ), avian dispersers, and host trees form a distinctive ecological network, providing an insightful model for monitoring the mutualistic system dynamics, so it’s crucial to identify the functional roles of these species in mutualism networks. This study maps the structural composition of mistletoe seed-dispersal network, and clarify the key species and processes that underpin network stability in temperate forest ecosystem. By combining field surveys, laboratory feeding experiments, germination trials, and meta-analyses, we revealed the mistletoe mutualism network exhibited high nestedness, moderate modularity, and strong connectivity. Bohemian waxwing ( Bombycilla garrulus ) and Aspen ( Populus davidiana ) were respectively the key animal and plant species in this network. Although mistletoe fruits are not the preferred food of Bohemian waxwing, the fruit consumption frequency increased to 73.53% during food-scarce winters, and their digestion significantly promoted the germination rate of mistletoe seeds. Additionally, infection by mistletoe elevated the mortality of host trees. To balance the own population survival and host sustainability, mistletoe reduces fruit attractiveness and prolongs the persistence period in winter. The dynamic equilibrium of the mistletoe–host system is jointly determined by dispersal intensity, host availability, fruit retention time, and the competitive fruit sources, through which mutualistic network stability is maintained by an “moderate dispersal” strategy between mistletoe and its seed disperser. These findings advance our understanding of mistletoe seed-dispersal mechanisms and also provide new insights into the stability of plant–animal mutualistic networks. • The mistletoe-centered network in temperate forest ecosystem exhibits high nestedness and modular features with clear keystone species. • Bohemian waxwing is the key seed disperser of mistletoe, particularly in food-limited winter. • Avian intestinal digestion significantly improves mistletoe seed germination compared to manual extraction. • Mistletoe and Bohemian waxwing stabilize the mutualistic network by “moderate dispersal” strategy to avoid excessive host tree exploitation.