The share of herbal plants in the segetal communities of river valleys

Abstract

The aim of the research was to comparatively assess herbal plants growing in arable fields adjacent both to Liwiec, Tyśmienica and Wilga rivers and to natural and semi-natural habitats. The studies were conducted on permanent plots, with the composition of herbal species established according to  their useful parts and distance from the river. Floristic observations were made during the growing seasons between 2016 and 2019 in the agrocenoses of Liwiec, Tyśmienica and Wilga river valleys. In the river valleys, a total of 143 species of herbal plants, with stems, leaves, flowers, roots and seeds as useful parts, were identified. The richest in herbal plants were agrocenoses of the Wilga valley, with 121 species, but those in the valleys of Tyśmienica (110 species) and Liwiec (108 species) were less numerous. In the river valleys, native species dominated among herbs, and their share was the highest in the immediate vicinity of the river and of the habitats neighboring arable fields. Further away from the river and from those habitats, their share in the communities decreased slightly. Inventoried species of herbs found in the agrocenoses of the river valleys were diverse in terms of their useful parts. The most numerous group were species from which stems as well as leaves can be obtained for pharmaceutical purposes. Species from which only roots/rhizomes can be used constituted a significant share in the flora of the communities. Such species occurred most often on permanent plots in the immediate vicinity of the rivers. Species whose useful parts might be roots/rhizomes together with both stems and leaves, or only flowers, or only leaves were less numerous. Similarity analysis of the communities in terms of the presence of herbal plants showed significant differences between the numbers of species from which flowers, leaves, both stems and leaves as well as seeds, or roots as well as seeds, or leaves as well as flowers can be obtained.