The Canadian goldenrod or woundwort (Solidago candensis) or the giant goldenrod (Solidago gigantea) recently they spread and thrived…on Facebook. Threatened by invasion, citizens traditionally call for something to be done. They condemn the irresponsibility of their fellow countrymen and lament the future of the planet. But they are surprised that the first examples of the species have been present on Poland since the second half of the nineteenth century. The mass autumnal flowering has been a phenomenon for at least ten years.

The subject is continuing to develop. The next candidates for the role of a horseman of the apocalypse are waiting. It’s a somewhat modest number. They form less than one percent of general Polish flora, that is to say 30 species from three and a half thousand that are making themselves known in adapting. They are known in Polish parlance as IGO (inwazyjne gatunki obce) or invasive alien species.

Rogues’ gallery

In the expert analysis on the Polish governmental website ,dane.gov.pl., at the top of the list among the invaders is the ailanthus altissima or “tree of heaven” (Ailanthus altissima) . In the Far East it is regarded as sacred often planted by temples grounds. In Europ it is often planted in parks as a decoration. But their roots are fast growing and can damage the foundations of nearby buildings or canals.

Next is the common ragweed (Ambrosia artemisiifolia). It has antibacterial properties, but is a strong allergen and s so it can destroy crops. It can form dense areas, choking off native species.

Then we have one of the tallest herbs in the world, the hogweeds Mantegazzio (Heracleum mantegazzium) and Sosnowski (Heracleum Sosnowskyi). They are known for their strong phototoxic furanocomarins or toxic chemical structures. Contact with these may mean blistering and a wound that takes a long time to heal. But in Lituanania at least it’s possible to buy honey, harmless, from its flowers.

There are many kinds of reynoutria, flowering plants; Japanese, Sakhalin and Czech (Reynoutria japonica, sachaliensis, bohemica). They are nasty, many-leafed shrubs that root up to three metres deep and can be grown from a piece of rootstalk measuring as little as a centimetre or so.

Further down , we can find commonly known species, less invasive the Boxelder Maple (Acer negundo). It is a common plant in parks and it sows itself along railway lines. There is also the small-flowered balsam (Impatiens parviflora) that has almost expelled its native relative, the touch-me-not (Impatiens noli-tangere) or the purple flowered balsam one of the tallest annuals in Europe (not counting vines).

Invasion strategy

Normally, a species that ends up in a new environment quickly dies. According to this rule of thumb only 10 percent of these arrivals can adapt and from these there are but  one in ten that can be classed as invasive. Not all researchers confirm this principle.

What decides on the invasiveness? Above all its the resistance to the climate and ground conditions linked to a fast growth rate, short life cycle, generating many seeds and an ability to seed vegetatively and creating tight areas of land and the ease with cross fertilisation with native species. In many cases, they can release inhibitors into the soil that block any other species from thriving.

Invasive species take over strongly modified and degraded ground close to human habitats. They are known as ruderal species. Next, they migrate to places that are more conducive to their original sources. They meet with no natural predators, multiply, win the competition with the natives and in some areas they are able to drive out up to 70 percent of rival native plants from their territories.

It may appear that this news is bad enough. Biodiversity is the Holy Grail for the specialists in nature protection. At the same time the modification of the environment caused by these aliens reaches even further. They can alter the water conditions and the lighting balance, Also they can even change the physiochemical composition on the soil. This has economic consequences and may in turn lead to the limiting of the uses of arable soil.

The dark side of progress

Despite all this, migration remains as old as life on Earth itself. Th problem lies that the scale has radically risen. The unprecedented economic contact, the ease and scale of travel and the appetite for the exotic in all species has created organisms, conducive conditions for expansion, that could only be dreamt of in the past. This, in its way could called a step forward because of the change effected by man, but only for chosen few.

There are other accumulations that the newcomers get to. Technological progress and one of it offshoots, large-scale agriculture have ensured that the number of natural environments have reduced greatly. Monocultural enterprises have taken over more and more land, for bananas, avocados and other  fruit as well as vegetables indispensable in the diet of a modern European. What’s worse this type of cultivation has a direct impact on its neighbours in more natural areas. The effect of this increase is that this attracts invasion, as it had become more attractive.

These realities were absent not all that long ago when the population was relatively small and travel was risky, undertaken usually through necessity. Travel was usually through rich and natural accumulations. In multi-species life assemblies where there were networks of interdependent dependencies. a species that was introduced found it more difficult to break through and live.

A gloomy future?

The problem come to worry the European Union to such an extent that in 2016 it established the category of “invasive species”, that it was forbidden either to grow or introduce. Poland adopted in 2021 legislation on invasive species. But if we look at the scale of the problem, the initiative of bureaucrats looks rather slim. You can start off in catastrophic tones. But you ca also humbly accept the fact that man cannot cope with some effects that he has caused. And hand the initiative over to Nature perhaps. Not all invasions are successful. Nor long lasting. The species one would think of as well established could suddenly leave. A rich mnoculture is like  a table groaning with produce and just waiting for a guest. And it pays to wait at times.

It’s worthwhile to think about the challenges faced by some organisms in the past. In the pre-Cambrian period (3.7 billion years ago) methane produced by bacteria almost finished off life. Cyaniobacteria, 2.4 billion years ago and its activity increased the amount of oxygen for a period of 20 million years. This eliminated many non-oxygen organisms. Th renewed volcanic activity after the end of the Permian period, 252 million years ago led to much of today’s Asia being covered by volcanic ash between 400 and 300 metres deep, the so-called Siberian Traps. We should not forget the meteorite either, that hit present day Gubbio in Italy, 66 million years ago, which ended the rule of dinosaurs.

Species , however unlikeable they may be have their “use-by dates” around 5 million years on average. Around 90 percent of species became extinct. Each extinction has been an opportunity for others to arise, unimagined beforehand.

–Hanna Pasierska

TVP WEEKLY. Editorial team and journalists

–Translated by Jan Darasz

Źródła:
   

  Michael J Benton When Life nearly Died [Gatunki inwazyjne jako zagrożenie dla bioróżnorodności, Materiały dla pracowników parków narodowych], Prószyński i S-ka, Warsaw 2017.
Zygmunt Dajdok, Michał Śliwiński, Maciej Romański, Anna Krzysztofiak, Lech Krzysztofiak Invasive Species as a threat to biodiversity. Materials for employees of national parks [Gatunki inwazyjne jako zagrożenie dla bioróżnorodności, Materiały dla pracowników parków narodowych], https://www.wigry.org.pl/inf_i_rozw/budowa_por/por4_4.htm. https://dane.gov.pl/pl/dataset/1760/resource/21068,inwazyjne-gatunki-obce-roslin-i-zwierzat/table?page=1&per_page=50&q=&sort=col5.
Głowaciński Z. (red.), Alien species in Polish fauna, Vol II. Problems and synthesis [Gatunki obce w faunie Polski. Tom II. Zagadnienia problemowe i syntezy], Published by Instutute for the Protection of Nature, Polish Academy of Sciences, Kraków, 2011, https://www.iop.krakow.pl/gatunkiobce/pliki/12.pdf.
Lech Krzysztofiak i Anna Krzysztofiak (red.) Invasive species and the threat to host natural environments[ Inwazyjne gatunki obcego pochodzenia zagrożeniem dla rodzimej przyrody], Krzywe 2015, conference materials, https://czlowiekiprzyroda.eu/wp-content/uploads/2017/07/inwazyjne_gatunki.pdf.
Internet project Research on the principles to combat invasive species and the introduction of educational pilot projects, http://projekty.gdos.gov.pl/igo-reynoutria-japonica.
https://kopalniawiedzy.pl/katastrofa-tlenowa-Ziemia-oliwin-tlen,27055