How do plant communities and flower visitors relate? A case study of semi-natural xerothermic grasslands

Damian Chmura,Paweł Adamski,Zygmunt Denisiuk

doi:10.5586/asbp.2013.015

Abstract

The paper examines the relationships between the species composition of flower visitors and plants in the semi-natural xerothermic grasslands in southern and central Poland. Thirty 10 × 10 m permanent plots were laid out in total, mainly in nature reserves. The vegetation units studied were classified according to the Braun-Blanquet system; these were phytocoenoses of the Festuco-Brometea classes Inuletum ensifoliae, Adonido-Brachypodietum pinnati and the transitional plant community. Entomological research was performed using the Pollard method within the same plots. A particular site was visited only once and different sites were studied between April and August 2008. We applied, among others, co-correspondence-analysis Co-CA, detrended correspondence analysis (DCA) and redundancy analysis (RDA) to investigate the co-occurrence patterns of plants and flower visitors and their biotopic requirements. We found that the species composition of flower visitors cannot be predicted by floristic composition when the duration of the study is restricted to one day (but under similar weather conditions); however, there is a positive relationship between the species richness of insects and plants and a positive relationship between the number of plant species and the abundance of flower visitors. The Ellenberg moisture index and the cover of meadow species significantly explained the species composition of insects. The three various vegetation units and five dominant xerothermic species, i.e. Adonis vernalis, Anemone sylvestris, Inula ensifolia, Linum hirsutum and Carlina onopordifolia that were studied across time differed in the species richness of insects. Our results demonstrate that possible patterns in the species composition and the assembly rules of flower visitors are not apparent when the Pollard method is applied. Based on the data obtained using this method, the flower visiting assemblages seem not to be driven by competition and they primarily show a tendency to co-occur which can be an artifact. A plant-focused method that included a rarefaction analysis yielded more insightful results and shed more light on the differences between the dominant plants that shape the physiognomy of plant communities in a possible pollination specialization.

Highlights

Grasslands are a vanishing and endangered habitat, due to changes in land use, the cessation of mowing and grazing and urbanization
Chmura et al / Relations between flower visitors and plants plant species on various levels: at the level of the species compositions of two data sets of communities; in terms of species richness and diversity; and at the level of single species that shape the physiognomy of the distinguished vegetation units
The main goal was to answer the question of which patterns are visible between plant and flower visitors during simultaneous field studies? To be more specific, we sought to answer the following questions: (i) do species-rich calcareous vegetation units attract species-rich entomofauna, i.e. especially flower visitors independent of the type of vegetation and the phase of the vegetation season; (ii) can the species composition of visiting insects be predicted based on plant species composition; (iii) do insect assemblages depend on local environmental factors or on the adjacent habitats as well, and; (iv) do dominant grassland plant species differ in the species diversity and richness of flower visitors?

Summary

Introduction

Grasslands are a vanishing and endangered habitat, due to changes in land use, the cessation of mowing and grazing and urbanization. Many case studies have addressed the processes of overgrowing by shrubs, trees and some forbs and have pointed to the need for the management. Chmura et al / Relations between flower visitors and plants plant species on various levels: at the level of the species compositions of two data sets of communities; in terms of species richness and diversity; and at the level of single species that shape the physiognomy of the distinguished vegetation units. The main goal was to answer the question of which patterns are visible between plant and flower visitors during simultaneous field studies? To be more specific, we sought to answer the following questions: (i) do species-rich calcareous vegetation units attract species-rich entomofauna, i.e. especially flower visitors independent of the type of vegetation and the phase of the vegetation season; (ii) can the species composition of visiting insects be predicted based on plant species composition; (iii) do insect assemblages depend on local environmental factors or on the adjacent habitats as well, and; (iv) do dominant grassland plant species differ in the species diversity and richness of flower visitors?

Methods

Results

Conclusion