Invaders in Hortobágy
Intensive treatments on the project areas aim at changing the vegetation that is different from the natural, due to inappropriate land use over a long period of time. Among the vegetation associations, the formation of grasslands and loess meadow vegetation would be optimal.
Due to intense, large-scale land management, such as shredding and intensive grazing, the vegetation covered areas can change suddenly. On the other hand, in the place of the disappearing reed meadow patches, it is sometimes not possible to create natural grasslands, because native species are simply killed in ecological competition.
Among the plants appearing in the competition, the so-called invasive plants pose a major risk. A common feature of these is that they are not native species, and in addition, they develop surprisingly well, they grow rapidly, usually bloom early, and ripen many seeds with good germination power.
These invasive plants easily prevent native species from competing for habitats and then displace natural association. Invasive plants create a relatively closed, homogeneous association. Interestingly, the shepherd culture in Hortobágy uses a separate term for the rapid and aggressive propagation of a plant species, in which case they say, "the field turns upside down" (Molnár, 2014).
In the Hortobágy areas, the appearance and rapid spread of aquatic invasive species appearing during drought along the rivers, marshlands with periodic water status are to be expected.
Among the invasive species appearing in the project area, we can highlight the Amorpha fruticosa, the Ailanthus altissima, the Asclepias syriaca and the Solidago gigantea.
It is difficult to control invasive species because they are highly resistant to mechanical effects. Cattle do not graze them so much as they are often stinging, heavily haired, or toxic, bad-tasting plants.
The easiest and most environmentally friendly solution to invade invasive species is mechanical weakening. In the case of herbaceous plants like milkweed, the mowing of the meadow is a possible alternative, or if the problem is quickly noticed and invasive plants appear only in a small area, they can also be successfully shredded or cutted. It is interesting to note that, in Hortobágy it was a common practice for herdsmen to be equipped with a special pitchfork, which ripped out different types of stinging weeds, such as Ononis spinosa, the Xanthium italicum, the Xanthium strumarium or other plants that were not grazed by the stock (Hajdú, 2011). It is difficult, however, to suppress these species only by means of mechanical weed control. Care must be taken before flowering, as this will prevent plants from multiplying. The already mature ripened plants are capable of scattering, so the species will re-appear.
In the case of planted forests, protection is more difficult to solve. In the case of relatively younger vegetation, it is possible to achieve a good result with the use of a forest chopper. There are chemical means as well. Since the use of glyphosating chemicals in protected natural areas is particularly risky, it is only possible to use special herbicides, such as injections or foam, in the form of gel, which serve the protection of non-target organisms. Such a special application method is also intended to reduce the risk of chemical drift and washing out.
Recent biological and ecological research has highlighted that more natural enemies of invasive species, such as insect species, fungi, and other pathogens, could be well used in biological control. However, it should be known that these organizations are not part of the domestic fauna, so their domestic ecological role is difficult.
Janó Ákos: Hortobágy pusztáról fú a szél... Tanulmányok az alföldi pásztorkodás köréből (Hortobágy, Kiskunság) / A Hajdú-Bihar Megyei Múzeumok Közleményei 62. (Debrecen, 2011)
A szúrós szerbtövis (Xanthium spinosum L.) növényfaj fitofarmakológiai áttekintése DOMOKOS ERZSÉBET 1*, KURSINSZKI LÁSZLÓ 2 , KELEMEN HAJNAL 3 , VARGA ERZSÉBET4*
A HAGYOMÁNYOS ÖKOLÓGIAI TUDÁS ETNOTÁJÖKOLÓGIAI ÉRTÉKELÉSE MTA doktori értekezés MOLNÁR ZSOLT, PhD MTA Ökológiai Kutatóközpont Ökológiai és Botanikai Intézet Vácrátót 2014
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