Wpływ zróżnicowania użytkowania krajobrazowego na cechy zgrupowań biegaczowatych (Coleoptera: Carabidae) obszarów rolnych = Effects of the diversity of landscape use on the characteristics of farmland ground-beetle assemblages

Abstract

We studied the effects of landscape structure and agricultural land-use on ground beetles (Carabidae) in a temperate farmland mosaic and homogeneous landscape. The research was carried out at twelve research sites located in two regional units, i.e. (a) the northern part of mesoregion 842.72 West Lake District in the macroregion of the Lithuanian Lake District and (b) in the southern part of mesoregion 313.44 Damnicka Upland, within the macroregion of the Koszalin Coastland. By administrative division, these positions are respectively: in the gmina of Dubeninki, voivodeship of Warmian-Masury (Rogajny and Łoje), and in the gmina of Przerośl in Podlasie voivodeship (Rakówek) – hereinafter referred to collectively as the “Dubeninki area”; as well as in the gmina of Potęgowo in the Pomeranian Voivodship (villages of Wieliszewo, Malczkowo, Darżyno and Darżynko – hereinafter referred to as the “Potęgowo area”). Four of the research sites were located in fields of large area, and four in complexes of small fields subject to traditional cultivation. The faunistic data comes from 12 transects (6 for each regional unit and 3 for each field type – large-area fields and complexes of small fields) using standard trapping methods (Barber˙s traps). A set of landscape-structure indicators adapted to the local scale of the study was then applied. Results point to a relationship between the structure of the landscape, the expressed number of patches of plant communities, the diversity of vegetation in the surroundings and the presence of trees in the landscape, and species richness and diversity of ground beetles. Where agricultural areas nevertheless have a diversified landscape these are characterised by greater species richness of Carabidae than homogeneous areas. Furthermore, the shorter the distance to the nearest tree, the greater the species richness and diversity of Carabidae. However, soil type, as well as soil diversity, at a study site and its vicinity are not found to exert a direct impact on the species richness of Carabidae. Different soil types may be characterised by similar grain size, and thus similar humidity conditions and soil reaction, with these in turn determining other habitat conditions of importance to the studied taxon.