Are macrophyte-dwelling Chironomidae (Diptera) largely opportunistic in selecting plant species?

Mónika Tóth,Arnold Móra,András Specziár,György Dévai,Béla Kiss

doi:10.14411/eje.2012.033

Abstract

In this study we evaluate how variations in taxonomic composition and physical structure of macrophyte stands affect plant-dwelling chironomid assemblages in highly variable macrophyte assemblages in two densely vegetated backwaters. By using multivariate explanatory techniques we found that similar vegetation composition did not unequivocally relate to similar chironomid assemblages, moreover the diversity of macrophyte stands did not correlate with the taxonomic diversity of chironomid assemblages in the backwaters investigated. Taxonomic composition and structural characteristics of the vegetation had little influence on the taxonomic or functional (i.e. feeding groups) composition of chironomid assemblages inhabiting them. Similarly, there are only weak relationships between the distribution of certain chironomid species or functional feeding groups and the environmental variables investigated. In general, the structure of the vegetation was more closely associated with the distribution of dominant chironomid taxa than compositional variables (i.e. density of specific macrophyte taxa). In summary, the structure of aquatic vegetation (i.e. position, size of a stand of vegetation, total plant density) and characteristics of the environment where it develops may be more important in shaping plant-dwelling chironomid assemblages than the taxonomic composition of the vegetation.

Highlights

Macro-vegetation is an important and complex habitat in aquatic ecosystems, and influences species diversity and composition of macro-invertebrate communities in several ways (Cheruvelil et al, 2002; Bogut et al, 2007; Papas, 2007; Cremona et al, 2008; Bogut et al, 2010)
We studied the association between variations in taxonomic composition and physical structure of macrophyte stands and plant-dwelling chironomid assemblages in two densely vegetated backwaters with highly variable macrophyte assemblages
The areas sampled were dominated by the macrophytes Ceratophyllum demersum and Stratiotes aloides, and by Sparganium erectum at BKHT

Summary

Introduction

Macro-vegetation is an important and complex habitat in aquatic ecosystems, and influences species diversity and composition of macro-invertebrate communities in several ways (Cheruvelil et al, 2002; Bogut et al, 2007; Papas, 2007; Cremona et al, 2008; Bogut et al, 2010). Several authors record that morphology of plants (Krecker, 1939; Harrod, 1964; Ali et al, 2007), the area of plant surface that is colonisable (Dvorak & Best, 1982; Cyr & Downing, 1988), seasonal changes in the pattern (Scheffer et al, 1984) or the biomass of vegetation (van den Berg et al, 1997) cause differences in the composition, density and diversity of plant-dwelling macroinvertebrate communities. There are many papers dealing with environmental influences on plant-dwelling macro-invertebrate communities, the taxonomic resolution of such studies are often limited, especially those on non-biting midges (Diptera: Chironomidae), which are commonly just classified to family or subfamily (but see e.g. Dvorak & Best, 1982; van den Berg et al, 1997). Chironomids avoid certain species of macrophyte and the distribution of especially their mining larvae (i.e. those living under the epidermis of leaves and stems of aquatic plants) is influenced by plant morphology

Objectives

Methods

Results

Conclusion