Open AccessOverstorey tree species regulate colonization by native and exotic plants: a source of positive relationships between understorey diversity and invasibility
Author(s) -
Knight Kathleen S.,
Oleksyn Jacek,
Jagodzinski Andrzej M.,
Reich Peter B.,
Kasprowicz Marek
Publication year - 2008
Publication title -
diversity and distributions
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.918
H-Index - 118
eISSN - 1472-4642
pISSN - 1366-9516
DOI - 10.1111/j.1472-4642.2008.00468.x
Subject(s) - understory , species richness , invasive species , introduced species , biology , ecology , native plant , colonization , woody plant , species diversity , biodiversity , plant community , canopy
The North American woody species, Prunus serotina Ehrh., is an aggressive invader of forest understories in Europe. To better understand the plant invasion process, we assessed understorey plants and Prunus serotina seedlings that have colonized a 35‐year‐old replicated common‐garden experiment of 14 tree species in south‐western Poland. The density and size of established (> 1 year old) P. serotina seedlings varied among overstorey species and were related to variation in light availability and attributes of the understorey layer. In a multiple regression analysis, the density of established P. serotina seedlings was positively correlated with light availability and understorey species richness and negatively correlated with understorey species cover. These results suggest that woody invader success is adversely affected by overstorey shading and understorey competition for resources. Simultaneously, however, invader success may generally be positively associated with understorey species richness because both native and invasive plant colonization respond similarly to environmental conditions, including those influenced by overstorey tree species. Identification of characteristics of forests that increase their susceptibility to invasion may allow managers to target efforts to detect invasives and to restore forests to states that may be less invasible.