ASSESSMENT OF OPUNTIA HUMIFUSA RAF., 1820 DISTRIBUTION PROSPECTS IN EUROPE UNDER GLOBAL CLIMATE CHANGE

Abstract

Species of the family Cactaceae – Opuntia humifusa (Raf.) Raf., 1820 belongs to a group of cacti of American origin that are protected in their native area but have spread to many regions of the globe and exhibit a pronounced tendency towards naturalization. In recent years, the expansion of this species has also been observed in the continental part of Ukraine. To predict the potential for further spread of this species, we conducted modeling of the current bioclimatic niche of O. humifusa based on open-access data and established the species’ tolerance limits to key bioclimatic environmental parameters. The most significant parameters determining the potential distribution of the species were precipitation, solar radiation seasonality, lowest weekly radiation, radiation of the wettest quarter, mean temperature of the coldest quarter, and minimum temperature of the coldest month. The obtained model demonstrates high reliability (AUC = 0,996), and its omission rate aligns well with the predicted omission dynamics calculated for test data derived from the Maxent distribution itself. The model of the potential current area of O. humifusa indicates that only a part of Ukraine’s territory (the southern part) falls within climatic conditions suitable for the species’ existence. Optimal climatic conditions for the species are found only in a few localized zones. Modeling the future dynamics of the species’ area under the influence of climate change suggests its significant expansion and northward shift in the near future. The primary changes are observed in the areas and spatial configuration of zones with varying suitability for the species’ existence. The optimal zone practically disappears in the 2080 model.Moderately suitable and suitable climatic regions significantly expand in the models up to 2080 and shift towards the northern regions of Europe.