Endogenous and exogenous factors that influence the success of stem fragments of aquatic macrophytes

Aim Many macrophyte species rely on stem fragments as their primary or complementary means of asexual reproduction. This systematic review synthesizes the key endogenous and exogenous factors that influence the success of these fragments, evaluated by their potential for colonization, regeneration, and the establishment of new plants. Methods Systematic review using the Web of Science and Scopus databases on 2 January 2025. This systematic review was complemented with additional sources identified through cross-referencing and manual searches. Results Macrophyte growth from stem fragments has been documented in 157 investigations (110 studies investigated the determinants of fragment performance) and 76 macrophyte species. Endogenous factors most frequently explored include the presence of nodes, fragment size, and stem position on the parent plant. Among the exogenous factors, desiccation, nutrient availability, and light are the most commonly investigated abiotic influences, while competition, herbivory and facilitation are important biotic interactions affecting fragment performance. Climate change (alterations in temperature, CO2 and precipitation) and eutrophication potentially drive shifts in macrophyte communities by impacting the success of asexual reproduction through stem fragments. Identified gaps include how the parent plant, grown in different conditions, influences fragment performance, a geographical bias toward economically important species in temperate regions, and insufficient integration of field and experimental research. Conclusions This review highlights that environmental abiotic factors and biotic interactions, typically studied for their effects on adult macrophytes, also play a crucial role in macrophytes establishment during the early life stages by influencing their asexual reproduction success via stem fragments. Recognizing the factors governing stem fragment reproductive success is vital for understanding macrophyte species distributions, and this knowledge should be incorporated into macrophyte metacommunity models.