Invasive alien species in Switzerland - Schweizer ...

Résumé 31
a stream in a valley, or an animal biomass of alien species of up to 95 % in the Rhine
near Basel, must have impacts on the native ecosystem. All species use resources and
are resources to other creatures and so they alter the web and nutrient flow of the
ecosystems they are living in.
1.6 Discussion
This report compiles the available information about IAS in Switzerland. During the
compilation it became clear that it is impossible to list all alien organisms, for the
simple reason that there is a gap in taxonomic knowledge, not only in Switzerland, but
Europe and the world, reflecting a need for more taxonomic work. There are probably
more than ten times the species described so far actually existing right now on the
planet, and for the species that have been described we often know little more than
their names. This gives a good indication that there will be more species of both native
and alien origin found in Switzerland in the years to come. Since all knowledge and
management are based on the concept of ‘species’, it seems obvious that taxonomic
work is crucial.
Despite the widespread view that IAS are of less concern in Central Europe than on
other continents (and more especially on islands) for various reasons, including the
small size of nature reserves and the high human impact on all ‘natural’ environments,
and the long association of alien species and humans leading to adaptation, however,
the number of cases of dramatic impacts is increasing and the awareness among scientists
and the public is steadily evolving. Thus, the threats from IAS should not be
underrated. One of the major consequences, which is undoubtedly unfolding before our
eyes, is global homogenization (catchily called McDonaldization), with the unique
character of places such as Switzerland being lost, the characteristic flora and fauna
invaded by organisms which often accomplish to form the largest biomasses in certain
ecosystems. This is fact and cannot be argued about, while confirmation of impacts is
difficult to obtain and can be controversial. The concept of ‘bad species’ and ‘good
species’ in our ecosystems is a rather anthropomorphic view. Even if a population of a
native species is enhanced, it is not necessarily good for the ecosystem but can disturb
the natural balances and nutrient and energy flows in the ecosystem. After an era of
exploitation, it is now time to address global warming and global swarming.
IAS should not be seen as a specific topic but rather as a part of conservation, trade,
and other activities. The main question to be answered is not how to deal with IAS, but
what should Switzerland look like, what are the goals for conservation, what should a
particular nature reserve or the national park look like? These goals need to be set and
IAS management will be part of this bigger picture to conserve and reinstate the unique
ecosystems and habitats of Switzerland. The intact ecosystems can deliver ecosystem
services in a sustainable manner.