Keywords
Biological invasions · Alien biomolecules · Caulerpa cylindracea · Halophila
stipulacea · Mediterranean Sea
1
Introduction
The nature of the interactions among species is crucial for structuring and stabilizing
ecological systems. In spite of this, few studies assess the role of species interactions
in driving ecosystem functioning [1]. This also applies to molecularly mediated
biological interactions [2], the role of which at higher levels of biological organization largely remains unexplored [3]. Although chemical ecology has opened our
“eyes” to the vast communicative interplay in which organisms use chemical signals
to find their food and mates, to deter predators, or to prevent pathogen invasion [4],
critical gaps remain in the study of natural products as mediators of ecological
interactions at the level of populations, communities, and ecosystems. Indeed,
chemoecological aspects have been only occasionally considered to draw conclusions about the impacts of bioactive natural products on biodiversity.
Terpenes, for example, represent the most abundant group of biogenic volatile
organic compounds in the atmosphere [5] and a kind of complex chemical language
mediating crucial ecological interactions [6]. Therefore, if we consider the critical
roles played by terpenes in chemical communication between plants and animals in
terrestrial environments, it becomes evident that they can affect biodiversity at all its
levels of organization. This is also true for marine environments, where terpenes are
also widespread and regulate interactions between benthic invertebrates [7], but also
applies to other groups of compounds, such as alkaloids or flavonoids, affecting
ecosystem stability as the long-term result of selective pressures and diffuse coevolutionary processes.
On the other hand, interactions between invasive and native species represent
a serious threat to biodiversity, with a potential for dramatic ecosystem destabilization and for generating evolutionary changes occurring within faster time scales.
Several studies have already shown that the evolution and spread of invasive species
can be rapid and dramatic, rising some of the most important current environmental
problems, but also offering interesting research opportunities to evolutionary biologists [8, 9]. In parallel, a chemoecological approach to biological invasions, especially in marine environments, has made it clear that the impact of marine invasive
species also depends on their chemical ecology and, consequently, on the functional
role of their bioactive natural products [9, 10]. Accordingly, a better understanding
of the chemoecological factors that affect marine biological invasions has currently
become an urgent research priority especially considering the exotic macrophytes
that entered the Mediterranean Sea and are able of replacing keystone native species,
causing environmental and economic damages [11]. By reviewing some of the
available literature on this topic, this article places emphasis on the critical roles
that biomolecules from invasive species can play in destabilizing marine
122
F. Defranoux and E. Mollo
Biological invasions · Alien biomolecules · Caulerpa cylindracea · Halophila
stipulacea · Mediterranean Sea
1
Introduction
The nature of the interactions among species is crucial for structuring and stabilizing
ecological systems. In spite of this, few studies assess the role of species interactions
in driving ecosystem functioning [1]. This also applies to molecularly mediated
biological interactions [2], the role of which at higher levels of biological organization largely remains unexplored [3]. Although chemical ecology has opened our
“eyes” to the vast communicative interplay in which organisms use chemical signals
to find their food and mates, to deter predators, or to prevent pathogen invasion [4],
critical gaps remain in the study of natural products as mediators of ecological
interactions at the level of populations, communities, and ecosystems. Indeed,
chemoecological aspects have been only occasionally considered to draw conclusions about the impacts of bioactive natural products on biodiversity.
Terpenes, for example, represent the most abundant group of biogenic volatile
organic compounds in the atmosphere [5] and a kind of complex chemical language
mediating crucial ecological interactions [6]. Therefore, if we consider the critical
roles played by terpenes in chemical communication between plants and animals in
terrestrial environments, it becomes evident that they can affect biodiversity at all its
levels of organization. This is also true for marine environments, where terpenes are
also widespread and regulate interactions between benthic invertebrates [7], but also
applies to other groups of compounds, such as alkaloids or flavonoids, affecting
ecosystem stability as the long-term result of selective pressures and diffuse coevolutionary processes.
On the other hand, interactions between invasive and native species represent
a serious threat to biodiversity, with a potential for dramatic ecosystem destabilization and for generating evolutionary changes occurring within faster time scales.
Several studies have already shown that the evolution and spread of invasive species
can be rapid and dramatic, rising some of the most important current environmental
problems, but also offering interesting research opportunities to evolutionary biologists [8, 9]. In parallel, a chemoecological approach to biological invasions, especially in marine environments, has made it clear that the impact of marine invasive
species also depends on their chemical ecology and, consequently, on the functional
role of their bioactive natural products [9, 10]. Accordingly, a better understanding
of the chemoecological factors that affect marine biological invasions has currently
become an urgent research priority especially considering the exotic macrophytes
that entered the Mediterranean Sea and are able of replacing keystone native species,
causing environmental and economic damages [11]. By reviewing some of the
available literature on this topic, this article places emphasis on the critical roles
that biomolecules from invasive species can play in destabilizing marine
122
F. Defranoux and E. Mollo