symposium on alien plant invasions in Chile
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The first symposium on Alien Plant Invasions in Chile was held in
Puyehue, Southern Chile in November 14th as part of the 45th Annual
Meeting of the Biological Society. The symposium discussed alien
plant invasions and their status in Chile. The initiative was the
first in bringing together specialists to discuss the global phenomena
of alien plant species from a Chilean perspective.
presents an interesting setting to study biological invasions. Chile
has a long history of introduction with ca. 723 alien plant species
(Concepción Herbarium unpublished data). The country also
has a high rate of endemisms, due to its biogeographic isolation,
which make it susceptible to invasion processes. Furthermore, Chile
is one of the few countries with temperate ecosystems in the Southern
Hemisphere, allowing for interesting comparisons with Australia,
New Zealand and South Africa as well with climatic parallels in
the Northern Hemisphere.
the other hand, even though invasions are recognized as a major
threat to biodiversity worldwide, little is known in developing
countries about these processes. Currently, Chile lacks a clear
policy on alien species. Research has been done sporadically, without
a unified conceptual framework and with little coordination among
institutions. This symposium offered a first opportunity to review
the existing evidence about plant invasions in Chile and to discuss
future challenges for research and management.
Bustamante, the chair of the symposium illustrated the importance
of studying invasions in Chile, highlighting some of the major challenges
in studying alien plant invasions in Chilean ecosystems.
Rapoport discussed the characteristics of human developments as
sources of propagules for plant invasions. He presented data from
London, Mexico City and Bariloche, showing that alien species tend
to concentrate around urban developments and decreased in their
abundance in natural areas. He also emphasized in the use of multiple
scale methods to study invasions. Finally, he suggested that many
exotic plant species are edible and may be an additional source
of food for urban people.
Pauchard emphasized the importance of the landscape context and
corridors in the introduction of alien species in protected areas.
He presented data from two Chilean national parks, where alien species
in roadsides are related to elevation, land use and landscape context.
He concluded that alien species should be controlled before entering
natural areas by managing the matrix that surrounds protected areas.
Becerra, using data from several published studies, searched for
relationships between native communities and invasibility in forests
from Central and Southern Chile. He studied the effects of vegetation
cover, native species richness, tree canopy cover and the pool of
alien species on alien species richness. He concluded that overall
vegetation and canopy cover is negatively correlated with alien
species richness. However, he found no clear trend in alien vs.
native species richness.
Bustamante presented results on the invasion of Pinus radiata (Monterrey
pine) into Nothofagus forest fragments of Central Chile, currently
surrounded by industrial pine plantations. He found that most P.
radiata seedlings tend to grow in fragment edges, reaching the interior
only in highly disturbed forest fragments. He suggested that these
forests are still resistant to the invasion of Pinus radiata, but
monitoring is needed to assess invasion processes in the long term.
Cavieres concluded the symposium with general recommendations, elaborated
previously by all guest speakers, about the future and challenges
of plant invasion ecology in Chile. The package of recommendations
may be useful for other developing countries with similar state
of knowledge of their flora and similar environmental and economic
as many other developing countries, faces similar challenges in
the study of alien plant invasions, but it also offers a unique
opportunity to study biological invasions in the Southern Hemisphere.
We expect that this symposium had helped to stimulate the scientific
debate about invasion ecology, promoting the development of coordinated
research on the topic that could help to answer local questions,
while contributing to find generalities in patterns and processes
associated with plant invasions.
Aníbal Pauchard, Lohen Cavieres, Ramiro Bustamante, Pablo
Becerra and Eduardo Rapoport