On December 2018, Sara Vicente's PhD project was partially presented at CESAM's workshop "Alien species in a changing world”. On this occasion, the focus was on the molecular ecology component, as described by the title of the presentation: "Beautiful nightmare: a molecular view of the invasive plant Acacia longifolia". Sara, Cristina Máguas and Helena Trindade responsible for the work.
Abstract:
Acacia longifolia (Andrews) Willd. is an invasive species worldwide, native from Southeastern Australia and Tasmania. It was introduced in Portugal by the forestry services to protect the sand dunes and for ornamental purposes, and quickly became a serious environmental and socio-economical problem. The invasive capacity of this species is linked to many factors, namely its symbiotic promiscuity for nitrogen fixing, fast and easy growth and high number of seeds. Seeds can remain dormant in the soil for several years and quickly germinate after forest fires, which are frequent and intense during the summer in the Mediterranean areas. A molecular study performed in Portugal showed that acacias have low level of genetic differentiation, despite showing strong differences in phenology due to different climatic conditionsa,b. This seems to indicate that acclimation is an important factor in acacia invasion, maybe through a quick response to environmental conditions without adaptation, through phenotypic plasticity processes. Still, the roles of genetic variability and phenotypic plasticity in the invasive process are far from understood. Further molecular studies, including epigenetics, are being developed aiming at characterizing acacias in their native environment, as well as in other invaded locations, to elucidate the invasiveness process.