Segetal phytobiota as a factor of ecological risks in agrophyto­ cenoses under climate change conditions

This study provides a comprehensive analysis of global scientific data concerning the impact of segetal phytobiota as one of the key factors of ecological risks in agrobiocenoses, particularly under climate change conditions, which act as a powerful abiotic stress fac­tor. In this study, weeds are considered as indicators of disturbances in the functioning of agroecosystems and soil degradation. It has been established that the level of weed infestation can serve as a marker of the adaptive potential of agrophytocenoses to abiotic stresses. Modern scientific studies on the influence of key environmental factors under climate change conditions such as temperature stresses, droughts, excessive moisture, decreased soil fertility, humifica­tion loss, and soil microbiota imbalance on the struc­ ture and dynamics of agrophytocenoses are analyzed. Special attention is paid to changes in the species composition of weeds, particularly the spread of in­ vasive and adventive species, which confirm high ecological plasticity, competitiveness, and ability to form dominant groups even under intense anthropogenic influence. The authors developed a fivelevel scoring scale for assessing ecological risks in agrophytocenoses based on their weed infestation level — from minimal (1 point) to high (5 points). This approach allows for assessing the level of ecological risks in an agrocenosis and rationally planning measures to control its phytosanitary state. It is shown that the level of eco­logical risk in crop fields is determined by the degree of agrocenosis weed infestation. It is proven that the reduction of ecological risk during ontogenesis is achieved through the application of agrotechnolo­ gies that regulate the level of weed infestation in agrocenoses and influence their development. The data obtained by the authors confirm that a reduction in ecological risk in agrocenoses is possible through timely ecological monitoring and the implementa­ tion of a complex of preventive, agrotechnical, and protective measures that promote increased adaptive resistance of agrophytocenoses and regulate their phytosanitary state. It has been established that the high ecological plasticity and adaptive properties of segetal vegetation contribute to the formation of zones within agrophytocenoses where weeds displace cultivated species, promoting the spread of herbicideresistant populations. Such processes create ecological risks due to threats to biodiversity and a decrease in the ecological stability of agroecosystems