Establishment constraints of an alien and a native conifer in different habitats

Alien plants are subjected to different biotic and environmental barriers that limit their establishment success in the introduced range. Pseud- otsuga menziesii (Douglas fir), a native conifer from Northwest America, is considered one of the most invasive forestry conifers in Europe. However, littl...

Descripción completa

Detalles Bibliográficos
Autores: Carrillo-Gavilán, Amparo, Espelta, Josep Maria, Vilà, Montserrat
Tipo de recurso: artículo
Fecha de publicación:2012
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/51674
Acceso en línea:http://hdl.handle.net/10261/51674
Access Level:acceso abierto
Palabra clave:Abies alba
Germination
Invasibility
Pseudotsuga menziesii
seed removal
Seedling survival
Descripción
Sumario:Alien plants are subjected to different biotic and environmental barriers that limit their establishment success in the introduced range. Pseud- otsuga menziesii (Douglas fir), a native conifer from Northwest America, is considered one of the most invasive forestry conifers in Europe. However, little is known about the ecological filters that constrain plant establishment at early life-cycle stages and differences in habitat invasibility to this species. We conducted field experiments to compare the establishment potential (i.e. post-dispersal seed removal, seed ger- mination, seedling survival and growth) of Douglas fir in beech forests, holm-oak forests and heathlands; and compared it with the taxonomically close native conifer Abies alba (Silver fir). Douglas fir seeds were more removed than Silver fir in holm-oak and in heathlands. In all habitats, seed germination was significantly higher for Douglas fir compared to that of Silver fir and, seedling mortality was extremely high in both species due to soil disturbance by wild boars and drought stress. Douglas fir mortality was only lower than Silver fir in beech forests. However, species did not differ in seedling growth. Overall, the probability of invasion success of Douglas fir decreased along the sequential stages of plant estab- lishment in all habitats. Only high seed germination rates of Douglas fir would predict its high invasive capacity but these advantages are counterbalanced by high seedling mortality. Results showed a mismatch between invasibility and current pattern of Douglas fir invasion in the study area. Therefore, future research focused on seed production and on different compo- nents of biotic resistance is recommended to eluci- date which processes are favoring its establishment success.