Ambrosia is common in Ukraine – who is she and where is she from?

During the mass flowering of ragweed, not only does the frequency of allergies increase, but so does the number of publications about it. But often, false information about ragweed appears even at the level of definition.

An image search for “ragweed” among the first 20 photos gave me 7 false photos that didn’t smell like ragweed.

It is often confused with Canadian goldenrod.

This species has conspicuous yellow inflorescences and whole leaves, which easily distinguish it from ragweed. It is also often suspected of allergy symptoms, but most often in vain - the heavy pollen of this plant is poorly carried by the wind, and therefore has an extremely low chance of getting on the mucous membranes of people.

Where did ragweed come from?

Ragweed (Ambrosia artemisiifolia) came to us from North America, which is its homeland. However, it has now spread to the rest of the continent, as well as Central and South America. Its invasion has encompassed Europe, Asia, and even Australia.

It is believed that ragweed arrived in Europe in 1873. It most likely traveled “on the hare” in shipments of red clover seeds and other crops. This marked the beginning of the triumphal march of the plant across new lands.

Its feral populations began to be recorded in Germany, and later in France, Great Britain, the Netherlands and Belgium. Over time, ragweed opened the eastern front, gradually penetrating the flora of Serbia, Croatia, and Hungary and not stopping.

This alien plant has been established in Ukraine since the beginning of the last century. It could have arrived here not only by accident - it was even specially grown here.

In 1914-1918, there was a center of ragweed cultivation within the current Dnipropetrovsk region. The German pharmacist Kricker tried to use the plant as a medicine - a substitute for quinine and as an anthelmintic.

For a long time, the distribution of the species in Ukraine was limited to a small area. Everything changed after World War II, which caused an explosive spread of many alien species. This happened due to the mass movement of people, cargo, and damage to the vegetation cover.

Success strategy

Ambrosia has all the prerequisites for developing territories with destroyed vegetation cover. The average plant produces 30-40 thousand seeds, and some specimens can produce 100 thousand.

Not all of them germinate for the next season – some are deposited for later use, forming a seed bank. These “investments” are reliably stored in the soil for up to 10 years, but there is experimental evidence of seed germination after 40 years of dormancy.

Consequences of the invasion

The massive development of ragweed changes the structure of vegetation. Not only does the plant reproduce rapidly, but ragweed uses environmental resources much more efficiently than other plants. This has extremely sad consequences, both for native species and for the soil, because it dries out and becomes poorer.

In addition, ragweed effectively shades nearby plants, making their lives more difficult. As a result, the vegetation we are used to changes, the temperature of the soil and surface air increases, and erosion occurs.

Ragweed poses a threat not only to the microclimate and aesthetics of cities and villages, but also to the preservation of rare habitats and plants. If improperly treated, this plant can spread to crops, reducing yields several times over.

But there is an even more serious impact on humans. From mid-July until the first frost, ragweed blooms en masse and causes severe allergies.

There is no hiding from ambrosia

A single plant can produce from 4 million to 10 billion pollen grains. They are easily spread by air for tens of kilometers. Pollen has been recorded at an altitude of 5000 m above sea level and at a distance of up to 160 km from the nearest ragweed growing site.

That is, sometimes you can experience allergic reactions to this plant, even if it does not grow in your city or village. Here are some that work well even remotely!

Allergic reactions in our body are caused by proteins contained in ragweed pollen. There are 11 of them, but the main ones are Amb a 1 (allergen E) and Amb a 2 (allergen K).

When ragweed pollen hits the mucous membrane of the nose and bronchi, these compounds provoke an immune reaction, which leads to tearing, increased body temperature, and severe inflammation of the mucous membranes of the upper respiratory tract, which can cause attacks of bronchial asthma.

The painful condition caused by ragweed is often accompanied by fatigue, increased irritability, decreased appetite, depression, and headaches.

There are studies that show that increased levels of carbon dioxide and nitrogen compounds, as well as warming, further increase the allergenicity of pollen.

To protect themselves, vulnerable people should limit their contact with pollen during mass flowering. This can be done by wearing respirators and medical masks, avoiding places with significant ragweed thickets (wastelands, construction sites, roadsides and railways), and keeping car windows closed when traveling through landscapes where the plant may grow.

And during periods when pollen concentration is highest, it is even worth closing the windows of your home.

It is best to consult with your family doctor about how to treat allergic syndrome.

Is it possible to fight ragweed?

Fighting ragweed is extremely difficult, because its mass spread was missed from the very beginning.

One option is to plant the affected lands with winter grains for a short time, because the North American guest is much more active in spring grain crops.

You can fight ragweed with chemical methods, but only in limited areas.

Where to start the fight against ragweed? It is worth encouraging people to find and report its outbreaks in cities and villages.

It is worth mowing ragweed thickets twice a season: before flowering and a month after. It should not be mowed in May-June and during the dry season without watering.

Ragweed can be destroyed mechanically - simply by pulling it out by the roots. This is especially effective if the plant grows around administrative buildings, kindergartens, schools, and in recreational areas.

And to prevent ragweed from taking over Ukraine, it is necessary to restore vegetation cover where it has been destroyed or damaged. This includes areas along the construction of new roads, wastelands, areas with displaced soil, etc.