ABSTRACT
As is known, in medicine and veterinary medicine, a large number of natural therapeutic agents and preparations are used, the source for which is an extensive group of plants of more than 20,000 species, including herbaceous forms. 1 Biologically active substances contained in plant biomass, like alkaloids, glycosides, flavonoids, organic acids, saponins, essential oils, gums, and other ingredients, have long been used as medicinal drugs for people and animals. These substances produced by plants serve to protect them from microorganisms, insects, and herbivores. Along with this, it should be noted that the protection of plants from herbivores is limited not only by biochemical substances, but also by a number of other defense mechanisms, their morphophysiological state, including roughness, the presence of spines, pungent odor, etc. Absence of this comprehensive protection would lead not only to the grassland vegetation disappearance but also to soil losses due erosion processes, that is, to the disappearance of the fundamental principle of the existence of the terrestrial animal and plant world. Considering the interaction of soil-plant-animal from a systemic point of view, we can distinguish three main ways to protect the soil from erosion. The authors of this study believe that general protection measures include decrease of natural pasture productivity due 66to the vegetational change, the manifestation of forage herbs toxicity under adverse growth conditions and at destruction of the sod due to ungulates the appearance of weeds which have poisonous and repellent properties and so as a rule not consumed by the animals; then there will the normal (herbage) restoration. At the same time, it is weeds that in the majority can relate to medicinal plants due to the content of the above-listed biologically active, including poisonous, substances in their composition. The use of such plants for prophylactic or therapeutic purposes by humans and animals is due to the fact that in minor concentrations biologically active substances, according to the Arndt-Schulz law, enhance biological phenomena in organisms and improve their condition. However, with an increase in doses of taken medicinal plants or their medicinal ingredients, first deceleration of life processes, and then oppression, or even death, can occur. 2 It is in natural ecosystems that largely determines the regulatory role of weeds, from the point of view of agriculture, or medicinal plants, from a medical point of view.
