NKFIH PD 137747 (2021–2024)
The role of the unintentional transport of seeds by horticultural trade in human-mediated long-distance dispersal
Project leader: Judit Sonkoly
Understanding dispersal is becoming more and more important in the face of global climate change and the ever-increasing anthropogenic habitat destruction and alteration. Long-distance dispersal (LDD) events are very rare and highly stochastic processes, but they are disproportionately important and drive several large-scale ecological processes of key conservation importance. Yet, we still have a very limited understanding of the frequency, extent and consequences of LDD. Humanity has been an important dispersal vector for plants throughout history with its importance increasing especially fast in recent times. A huge number of plant species is intentionally dispersed and cultivated by humans, but it is often associated with the dispersal of contaminant species. Although the increasing global trade of container plants and horticultural substrates has a high potential to disperse propagules, this issue has rarely been studied from an ecological point of view and hardly been considered as a form of LDD. Besides introducing new alien species, the unintentional dispersal of propagules by horticultural trade probably constitutes a more general LDD pathway for a large number of species, both native and alien, consequently having complex effects on plant populations and communities. As this potential pathway of LDD represents a serious knowledge gap, making further investigations of this issue is critically important.
The specific aims of the project are (i) to evaluate the potential of horticultural substrates to disperse plants, (ii) to identify species that are dispersed this way, (iii) to determine species groups that are most likely to be dispersed this way by using trait-based analyses, (iv) to identify factors that influence the ability of horticultural substrates to effectively disperse plants, and (v) to synthesize the gathered data and assess the potential effects on plant populations and communities. The research project will promote our understanding of what traits determine the ability of plants to disperse this way, by which we will be able to delineate species groups able to spread via substrates and have a better approximation of the consequences. Identifying factors that influence the ability of horticultural substrates to disperse seeds will also enable us to give better estimations of the magnitude and effectiveness of this dispersal pathway. Besides conducting experiments and surveys to explore the extent and possible consequences of the unintentional dispersal of seeds by horticultural trade, reviewing and synthesizing the available knowledge of this phenomenon is vital to raise awareness and promote future studies of this issue.