Long-term demography and spatial genetic structure reveal mechanisms of Sassafras albidum population persistence through clonality.

premiseVegetative regeneration is a key mechanism of woody plant persistence in forest ecosystems, and the coupled roles of basal sprouting and clonal growth in shaping long-term population dynamics have been understudied. Basal sprouting replaces stems at fixed ramet locations, whereas clonal growth via root suckering produces spatially distinct ramets that promote genet-level persistence across space. Sassafras albidum, a clonal understory tree native to eastern North America, employs both mechanisms, making it an excellent system for evaluating how sprouting and clonality interact to structure populations.

methodsWe combined over two decades of demographic data with spatially explicit microsatellite analyses to examine population structure, spatial genetic organization, and persistence mechanisms in an upland oak-hickory forest on the Cumberland Plateau, Tennessee.

resultsWithin a 1-ha plot, we identified 31 genets, ranging from single-ramet individuals to large clones exceeding 100 ramets and spanning more than 8000 m

conclusionsWe propose that the combined effects of basal sprouting and clonal growth generate persistent regenerative ramet locations, allowing genets to maintain advance regeneration across heterogeneous environments. These processes decouple stem turnover from genet turnover and facilitate long-term persistence in resource-poor upland forests.