Prunus serotina unleashed: invader dominance after 70 years of forest development

Abstract

Propagule pressure and disturbance have both been found to facilitate invasion. Therefore, knowledge on the history of introduction and disturbance is vital for understanding an invasion process, and research should focus on areas in which the invasive species has not been deliberately introduced or managed to study unconfounded colonization patterns. Comparing the outcome of such spontaneous colonization processes for different ecosystems might provide a useful framework for setting management priorities for invasive species that enter new, uninvaded areas. We focused on the 70-year spontaneous spread of the invasive tree species Prunus serotina in a pine forest in the Netherlands. To reconstruct the invasion pattern, we combined historical maps, tree ring analysis, spatially explicit tree inventory data, seed density data, and regeneration data for both native and non-native species. Prunus serotina was the only species that showed successful regeneration: the species was present throughout the forest in the tree, shrub, and herb layer. Native species were not able to outgrow the seedling stage. Our data demonstrate that P. serotina is a gap-dependent species with high seed production that builds up a seedling bank. We also compared the results of this study with a similar study on P. serotina colonization in a deciduous forest in Belgium, where P. serotina invasion was not successful. The sharp contrast between the outcomes of the two invasion processes shows the importance of studying an invasive species and the recipient ecosystem jointly and made us raise the hypothesis that herbivore pressure may facilitate P. serotina invasion.

The non‐native plant Rosa multiflora expresses shade avoidance traits under low light availability

“…Based on our work, current management techniques should focus on removal of edge populations, which serve as potential sources of spread into younger forests with more open canopies. High seed production at forest edges combined with the ability to form a seed bank may promote the spread of R. multiflora into forest interiors, as observed for other gap‐dependent invasive species (Vanhellemont et al, 2010). Once canopy gaps exist, areas should be monitored regularly to prevent new plants from becoming established and building reserves, since R. multiflora success in the understory is strongly linked to an open canopy (Matlack and Schaub, 2011) and declines with canopy growth (Banasiak and Meiners, 2009).…”

Back to the roots: how do seedlings of native tree species react to the competition by exotic species?

“…Both species are among the 18 most invasive terrestrial plant species (DAISIE Project 2009). They are considered to be under the most aggressive exotic tree species in European forests and are regarded as strong competitors of native tree species (e.g., Kleinbauer et al 2010;Vanhellemont et al 2010). P. serotina was one of the first North American tree species that was introduced to Europe (Starfinger et al 2003).…”

Spatial genetic structure and clonality of Prunus serotina Ehrh. during invasive spread into Scots pine forests

“…In its native range, P. mahaleb was shown to disperse seeds at considerable distances, reaching over 900 m, but local seed movements dominate, similarly to P. serotina (García et al 2007). The role of long distance dispersal is one of the focal points in studies on biological invasions, emphasizing the great invasive potential of frugivorous species (Von Der Lippe and Kowarik 2007; Vanhellemont et al 2010;Pergl et al 2011;Amodeo and Zalba 2013). Gosper et al (2005) showed that the structure of the landscape, i.e.…”

“…7% of the stand. Studies on invasion patterns in P. serotina consistently report its high colonization effectiveness in Scots pine stands, or generally in coniferous stands and young forests, in contrast to lower effectiveness in fully developed forests and non-coniferous stands (Chabrerie et al 2007a(Chabrerie et al , 2007bVanhellemont et al 2009;Vanhellemont et al 2010;Jagodziński et al 2015). This trend reflects the divergent light conditions in these stands and light demands of black cherry, which attains highest growth, reproduction and probability of colonization in good light conditions (Closset-Kopp et al 2007;Knight et al 2008;Closset-Kopp et al 2011;Jagodziński et al 2015).…”

“…Currently, the species is naturalized but mostly invasive in much of Central Europe where it typically invades Scots pine-dominated stands. Recent studies have clearly showed the adverse effects of black cherry invasions in forest stands including limiting recruitment of native species (Vanhellemont et al 2010), shifting forest community structure (Halarewicz and Żołnierz 2014) or even changing ecosystem functioning by altering nutrient cycling leading to a reduced carbon sequestration capacity of native species (Aerts et al 2017). Leaves of P. serotina are successfully used as an alternative food source for native insect pests (Karolewski et al 2014) that increases the food base for the insect pests of the native bird cherry (Prunus padus L.).…”