Seed Dispersal as a Multiphase Process: Integrating Abiotic and Biotic Vectors Across Ecological Gradients

Seed dispersal is a dynamic process through which diaspores (seeds or seed-bearing fruits) are detached from the mother plant, transported to different sites in the landscape that offer physical protection, competitive advantages, or lower predation risk. A variety of biotic and abiotic factors contribute to seed dispersal processes, resulting in a high diversity of dispersal systems observed in nature. At present, the relationship and classification of seed dispersal processes remain unclear. It is therefore essential to delineate seed dispersal systems and understand their functional traits in relation to ecosystem functioning and diversity, in order to elucidate plant distribution patterns. This review presents an updated synthesis of current knowledge on multiphase seed, reframing diaspora dispersal systems (fruits with seeds) as dynamic networks of transitions rather than discrete events, with particular emphasis on their efficiency and legitimacy. Three operational phases were defined: primary release, secondary transit and deposition, and the filters acting at each stage, including physical abrasion, digestive modification, vector movement, and habitat boundaries. To achieve this purpose, an analysis of 115 bibliographical references was conducted, ensuring the inclusion of seminal works from preceding years. We specifically describe how endozoochory and diploendozoochory can be considered efficient and legitimate dispersal systems for plants, as well as the potential benefits of a triple endozoochory process. Likewise, we propose a network-based framework to model multiphase dispersal, integrating movement ecology, gut retention, and seed condition metrics. This review demonstrates that diaspore dispersal is a multifactorial process associated with intrinsic attributes of the diaspores, their dispersion agents, and their interactions with the environment and proposes a subtype of seed dispersal by endozoochory (triploendozoochory). By highlighting the ecological relevance and conservation implications of multiphase dispersal, this review calls for interdisciplinary research to quantify its contribution to plant connectivity, especially under global change. Recognizing predators, waterbirds, and caching agents' key multiphase vectors reframes their role in ecosystem resilience and restoration.