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Alien Newcomers Populated Entire Territory Of Russia

June 20, 2003

It is no secret that civilization is replacing wild nature. It is a common saying that animals and plants disappear one by one and get registered in the Red Books. However, few people know that developing new territories enriches flora. Only specialists are aware of the extent of the process: in each region and each province alien plant newcomers make significant part of the entire plant variety.

Are the new settlers numerous? According to researchers of diverse institutes, they are multiple. For example, in Mordovia they account 375 species, in the Yaroslavl Region - 303, in the Tula Region - 389, in the Tver Region - 457, on Karelian Isthmus - approximately 400, in Udmurtia - 800, in the Ukrain - 796. In the parks of the town of Voronezh, agrestal plant species make 55%, in parklands of towns of Karelia - 68%, on Solovki Islands - 29%, in the valley of the Lower Volga - 25%, in the Kirov Region - 20%, in Mineralye Vody (Caucasus) - 15%.

What kind of plants are they? The most well-known of them are the weeds that acclimatized in the plough-lands and have settled together with cultivated plants since olden days. However hard you may try to purify grain, little admixtures of weeds remain. During World War II, imported grain brought a lot of plants from the south of Eurasia and America to Vyborg area, and these plants could be found only around mills. Once the mills disappeared, so did the alien plants. At the end on 20th century, more than 60 new plant species were brought with imported grain to the town of Ivanovo: their nidi still concentrate on the territory of the flour-grinding plant, provender mill and along the branch lines towards them. In Udmurtia, 237 agrestal species were brought with foodstuffs fodder grain, the majority of "grain-crops" immigrants arriving from North and South America, Western and Southern Europe, Mediterranean, Western Asia, Southern Siberia. Other 89 species were brought with southern fruits and vegetables: water-melons, muskmelons, grapes, plums, onions, etc.

Another way of moving alien species in is flight from the crop. When planting the greenery in settlements, alien plant species are normally used with the focus on the most beautiful and undemanding ones. Unpretentiousness is also appreciated in cultivated plants, that are cultivated as odder crops, industrial plants and nectariferous plants. Being undemanding is the characteristic that allows them to survive even after the fields or flower-beds are neglected, and to settle down. They include well-known multicolored lupines, hedge bindweeds, mallows, some poplar species, coriander, water rice and poisonous gigantic Sosnovsky cow-parsnip.

Some plants are unexpected "guests" as they get to new areas with the soil stuck to motor-car tyres, with package, and by railway. A lot of plants do not last long as the new climate does not suit them. But their seeds are brought over and over again. More than fifty plant species were discovered along railways of Moscow, these plants are found nowhere else or extremely rarely. In Udmurtia, 100 plant species were brought with sand, gravel, crushed stone and other construction materials, other 34 species arrived with imported sea shells. Unknown hybrids are often found along tracks - in the areas where there are many newcomer plants.
The number of alien plants is growing fast. In the first quarter of the 20th century, slightly more than 150 alien species were recorded in the central districts of the non-black earth zone of European part of Russia. By the end of the 20th century their number exceeded five hundred. Flora of Karelia was enriched within the last 20-25 years by 150 plant species which are considered agrestal, one of these species originating from the Himalayas.

The plant migration processes are becoming global, symbiotic and parasitic organisms being distributed along with plants, including pathogenic fungi and insects (ticks, plant-louses) which attack local plant species. It is often the case when alien plants replace local native species. It has turned out that in the Moscow Region a new settler of North American origin - stick-tight beggar-ticks (Bidens frondosa L.) - is extensively spreading in European part of Russia and has practically replaced the local Trifid bur-marigold (Bidens tripartita), and in the Rostov Region it has replaced another native plant - devil's beggartick (Bidens frondosa).

Some of the newcomer species are very aggressive. Numerous scientists are alarmed with a North-American plant - Western ragweed (Ambrosia psylostachya) (Ambrosia artemisiifolia) - spreading all over the territory of the former USSR, as the plant has the nature of ecological outburst. As of today, the total area in the Russian Federation where this weed has settled equals about 6 million hectares. By the area of settling this seed takes the first place among the quarantine agrestal plants. These seeds are choking all other plants, growing as densely as 700 plants per square meter, their height making up to two meters.

Does that mean that we shall soon be surrounded by bushes of weeds and they will replace our favorite meadow and forest plants? No, the point is different. "In the conditions of European Russia we can hardly find a lot of examples of alien plants' intrusion into steady zonal communities, explains D.V. Geltman, employee of the Botanical Gardens of Russian Academy of Sciences (St. Petersburg). In the majority of cases we discuss intrusions only into seminatural or disrupted communities". That means that to protect Russian flora from alien intruders, it is important to save local natural communities, and the necessity of such protection is evident.

Informnauka (Informscience) Agency