Definition of exotic species (Wikipedia):
Exotic species are species living outside their native distributional range. They have arrived there by human activity, either deliberate (for economical purposes) or accidental (for example by ‘travelling’ along with tourists). Some so-called ‘introduced’ species are damaging to the ecosystem they are introduced into. In some cases they suppress, infect or mix with the native species and consequently change the ecosystems. Exotic species therefore are considered to be a worldwide threat to biodiversity. There are also exotic species that cause health problems or economical damage.
The aim is to create a garden, in the museum, that could present a real danger to the eco-system if any of the plants and/or animals were to ‘escape’. This means it is essential that anyone wishing to enter the garden puts on a protective suit and after their walk in the garden has a sort of ‘dry shower’ to remove any seeds or spoors. As long as this selection of plants remains within the garden, they are only potentially dangerous. But if they find their way into the natural surroundings the danger becomes real. It is not only the public, but also everyone involved in the organisation who must realise that literally not one single particle of these plants may ‘escape’. All the safety risks and measures are part of the work of art itself: setting it up and dismantling it, destroying the plants after the exhibition and so on. It is also essential that everyone involved is well-informed and documented about all the possible dangers.
Some of these plants have a strange beauty while being extremely aggressive at the same time: they can grow to 2 or 3 metres high in just a few months. EXOTE is the negative counterpart to the Garden of Eden. This is potentially the landscape of our future. If biodiversity continues to be eroded, we shall end up in the landscape I want to display here: a ‘poor’, inhospitable mono-world where only a few species grow, while the people who live there have to protect themselves in all sorts of ways from an environment they have themselves created. This idea is an extension of several traditions: tropical botanical gardens (such as the Royal Hothouses), biological laboratory experiments, ornamental gardens, etc.
To make the selection of flora and fauna, cooperation are established with scientists. They have the knowledge and expertise needed to make this project work. For EXOTE I (2011, BE) we worked together with the University of Diepenbeek and the Z33 contemporary art centre in Hasselt. During EXOTE II (2016, SP) we were adviced by the Ecology and Plant Biology department EHU/UPV, ICARUS (Environmental Studies), EL KARPIN (Wildlife Centre), BRINZAL (Recovery Center for nocturnal birds of prey) and the Bilbao City Hall Gardening Department.
EXOTE I (2011, BE)
We only have to think of the plant called Japanese Knotweed (for a detailed description see appendix 1), which effortlessly grows through concrete, for it to become clear that we shall not be dealing with a ‘normal’ garden. In appendix 2 you will find a list of plants that can be considered for this garden. It is not difficult to make a similar list of animals.
Fallopia japonica, synonyme: Polygonum cuspidatum, is a member of the family Polygonaceae. Japanese knotweed is native to eastern Asia in Japan, China and Korea. In North America and Europe (also: the Netherlands and Belgium) the species is very successful. In the U.S. and Europe, Japanese knotweed is widely considered an invasive species. It is listed by the World Conservation Union as one of the world's 100 worst invasive species.
The invasive root system and strong growth can damage foundations, buildings, flood defences, roads, paving, retaining walls and architectural sites. The success of the species has been partially attributed to its tolerance of a very wide range of soil types, pH and salinity. It is a frequent colonizer of temperate riparian ecosystems, roadsides and waste places. It forms thick, dense colonies that completely crowd out any other herbaceous species and is now considered one of the worst invasive exotics in parts of the eastern United States. Its rhizomes can survive temperatures of −35 °C and can extend 7 metres horizontally and 3 metres deep, making removal by excavation extremely difficult. The plant is also resilient to cutting, vigorously re-sprouting from the roots.
The most effective method of control is by herbicide application close to the flowering stage in late summer or autumn. In some cases it is possible to eradicate Japanese knotweed in one growing season using only herbicides. To eradicate the plant the roots need to be killed. Picking the right herbicide is essential, as it must travel through the plant and into the root system below. Glyphosate is the best active ingredient in herbicide for use on Japanese knotweed as it is ’systemic’; it penetrates through the whole plant and travels to the roots.
It takes about 3 weeks for most of the plants to die. After 3 weeks, all remaining plants should be sprayed again. This process needs to be repeated until all the plants die. Typically this can take 3 years.
List of invasive plants
- The barbary fig puntia ficus-indica was introduced in the 19th
century in Australia, but spread out to and overgrew ten thousands of hectares
- The pampas grass, especially the Cortaderia jubata, is well-known as an invasive species noxious weed in the west coast of the US, in New-Zealand, Australia and South-East-Turkey.
- The common Water Hyacinth (Eichhornia crassipes) is an invasive species of plant which is native to the Amazon basin. The plant was introduced by Belgian colonizers to Rwanda to beautify their holdings. There, without any natural enemies, it has become an ecological plague, suffocating the lake, diminishing the fish reservoir, and hurting the local economies.
- The Hottentot Fig (Carpobrotus edulis) is a creeping, mat-forming succulent species, is native to South-Africa and has escaped from cultivation to become an invasive species.
- Caulerpa taxifolia is a species of seaweed that found its way into the Mediterranean sea. The species has a natural predator, a tiny aquatic slug (Elysia subornata).
- Passiflora tarminiana is an invasive species in Hawaï, where it is called “banana poka”.
- Canadese goldenrod was introduced in Europe as ornamental plants, but spreads out strongly and can bes een as a threat to the native species. The species is established as an invasive weed in many parts of Europe and China.
- Hawkweed (Hieracium) was introduced in New-Zealand more than hundred years ago by the English colonizers. The classification of Hieracium into species is notoriously difficult. One reason is the apomictic reproduction (in which plants asexually produce seeds), which tends to produce a lot of minor geographical variation. Over 9000 species names have been published in Hieracium but some botanists regard many of those as synonyms of larger species.
- Kudzu (Pueraria lobata) is a climbing, coiling, and trailing vine native to southern Japan and southeast China. Kudzu has earned such nicknames as the "foot-a-night vine", "mile-a-minute vine", and "the vine that ate the South" (of the United States).
- Echinocystis lobata is a genus in the gourd family Cucurbitaceae. The species is an annual vine, native to North America. This plant can be weedy or invasive according to some authoritative sources.
- The Black Cherry (Prunus serotina) was widely introduced into Central Europe in the mid 20th century. It has acted as an invasive species there, negatively impacting forest community diversity and regeneration.
- Chufa sedge or earthalmond (Cyperus esculentus). The earthalmond probably came to Europe in 1970. The plant is often cultivated for its edible tubers (tigernuts). The earthalmond is extremely difficult to remove and is considered an intrusive weed.