Temporal changes in the spatial distribution of carabid beetles around arable field-woodlot boundaries

Michal Knapp,Jana Knappová,Miroslav Seidl,Pavel Saska,Martin Macek

doi:10.1038/s41598-019-45378-7

Abstract

Carabids are considered beneficial arthropods in agroecosystems, where they prey on crop pests or consume weed seeds. Therefore, knowledge of the spatial distribution of carabids in agricultural landscapes is crucial to efficiently manage the ecosystem services that they provide. In the present study, we investigated the spatial distribution of carabids around arable field-woodlot boundaries in different seasons: (1) early spring, (2) late spring, (3) summer and (4) late autumn. The spatial distribution of carabid abundance (activity-density) and species richness varied seasonally, and the total abundance was highest within arable fields, except in early spring when it peaked at the boundaries. The observed pattern was mainly driven by the spatial distribution of the open-habitat species, which aggregated near the field boundaries during winter and early spring. The open-habitat species penetrated into woodlots during the summer season but occurred almost exclusively outside woodlots in the other sampling periods. The abundance of the forest species was highest within woodlots with the exception of the early spring season, when their abundance peaked at the boundaries. Carabid species richness was highest within arable fields in close proximity to woodlot boundaries with the exception of the summer season, when the total species richness was similar across habitats.

Highlights

Human activities have significantly altered the environment at the global scale, and this process has been accelerated during the last century[1]
We investigated the spatial distribution of carabid beetles around field-woodland boundaries from early spring to autumn, and we were especially interested in the temporal variation in the relative distribution of carabid abundance and species richness near field-woodlot boundaries
Our results clearly showed that the spatial distribution of carabid beetles in agricultural landscape varied over time

Summary

Introduction

Human activities have significantly altered the environment at the global scale, and this process has been accelerated during the last century[1]. Non-crop habitats within agricultural landscapes host species-rich and often abundant carabid assemblages that can spill over into adjacent arable fields and have the potential to suppress pest populations[12,16,18]. The existing data on seasonal changes in the distribution of carabid beetles around arable field-woodlot boundaries are limited. We investigated the spatial distribution of carabid beetles around field-woodland boundaries from early spring to autumn, and we were especially interested in the temporal variation in the relative distribution of carabid abundance and species richness near field-woodlot boundaries. We hypothesized that all groups (open-habitat specialists, habitat generalists and forest specialists) accumulate at the field-woodlot boundaries during early spring and late autumn because habitat edges are suitable overwintering sites for ground beetles[20,21,22]. We hypothesized that open-habitat specialists spill over into adjacent woodlots during summer and autumn as a result of agricultural operations (disturbances) in arable land[27]

Methods

Results

Conclusion