The conditionality of the formation of territorial species complexes of weeds by natural and anthropogenic factors

Territorial species complexes of weeds consist of a pool of species of regional flora (formed under the influence of natural factors), confined to secondary habitats with disturbed (natural or anthropogenic) vegetation and soilcover. Each territory is characterized by a certain species complex, the formation of which is due to the correspondence ofthe indicators of heat and moisture supply of this territory to the requirements of each type of weed plant of this complexto the main factors affecting the spread of plants – heat and moisture. This is the basis for the method of ecological andgeographical analysis, which consists in comparing the factors limiting the distribution of each species in the northern (indicators of the isoline of the sum of active temperatures above +5 ° C, describing the northern border of the weed species’range) and southern (indicators of the SCC isoline, describing the southern border of the species’ range) directions withthe indicators of heat and moisture availability of the studied territory. The species complex identified in this way is implemented within the region on a variety of secondary (disturbed) habitats, of which only those formed by anthropogenic means are taken into account in phytosanitary zoning. The equivalence and irreplaceability of the action of natural andanthropogenic factors is the basis for the formation of weed flora, as well as phytosanitary zoning in relation to weeds andlong-term forecast of their distribution.