Vitality dynamics of populations of some legume species in floodplain meadows of the Psel river basin under grazing and haymaking (Ukraine)

Abstract

The results of the study of the vitality structure and its dynamics in the three species of the Fabaceae family (Trifolium repens L., Medicago falcata L. and Vicia cracca L.) in the floodplain meadows of the northeastern Forest-Steppe of Ukraine under grazing and haymaking are presented. The analysis of the vitality structure of the populations of the three studied species of legumes in the control areas of the pascual and fenisicial gradients has shown that they are well adapted for existence in conditions without anthropogenic loads. It has been established that Trifolium repens is more resistant to both grazing and haymaking loads. This is evidenced by the preservation of the equilibrium status of the populations until the last stages of both gradients, as well as the obtained indices of vitality dynamics (IVD, in most cases less than 1, with the positive and negative signs). The Vicia cracca populations are characterized by considerable vulnerability to pasture loads, which is manifested in the sharp transition of populations to the category of depressed at the stages of PD1. This species completely falls out of the composition of the meadow phytocoenosis at the stage of the gradient PD2. In relation to the haymaking load, the species is quite resistant and can withstand both one-time (FD1 stage) and two-time (FD2 stage) haymaking per season, where the populations have the status of equilibrium, and IVD is less than 1. Haphazard haymaking causes significant changes in the vitality composition (IVD is greater than 1 with the negative sign) and the transition of populations to the category of depressed. The populations of Medicago falcata are well adapted to moderate grazing loads (stages PD1 and PD2), as evidenced by IVD less than 1 and maintaining the status of populations at the level of prosperous and equilibrium. Starting with the stage PD3, the populations undergo significant changes in vitality composition (IVD = -1.5060) and transfer to the category of depressed. On the fenisicial gradient, the Medicago falcata populations demonstrate resistance at the FD1 and FD2 stages. Only under haphazard haymaking (FD3), vitality composition is significantly transformed, as evidenced by the depressed status of their populations. The data obtained indicate the need to regulate both grazing and haymaking loads in order to preserve the integrity of meadow ecosystems and ensure the sustainable, long-term and effective provision of a range of ecosystem services by them.