A Test of the Species–people Correlation for Stream Macro‐invertebrates in European Countries

Abstract

Many recent studies have shown that over large scales there are positive correlations between plant and vertebrate species richness and human population presence. It is unknown whether this pattern applies also to Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies) (EPT), which are common bio-indicators of the naturalness of streams. Most local studies report higher species richness of these macro-invertebrates where human influences on water quality are lower. Using a newly collated taxonomic data set, we studied whether the species richness of EPT is related to human population size in European countries. Analyses controlled for country area, plant species richness, and mean annual temperature and precipitation. We found a significant increase in the number of EPT species with increasing human population size, plant species richness, and decreasing temperature. Our analysis confirmed the scale dependence of the human population-biodiversity correlation. Although stream macro-invertebrates are traditionally used as indicators of pristine ecosystems over local to regional scales, over broad scales more populated regions have more EPT species than less populated ones. This finding underlines the importance of scale in ecology and implies that there is a challenge also for the broadscale conservation of EPT diversity.

Is the human population a large‐scale indicator of the species richness of ground beetles?

“…For reasons of data availability, the majority of the studies of the regional species–people correlation have dealt with plants and vertebrates (Luck, 2007). However, there is recent evidence for analogous findings with some invertebrate groups such as ants, butterflies, grasshoppers and stream macro‐invertebrates (Luck et al , 2004; Pautasso & Fontaneto, 2008; Schlick‐Steiner, Steiner & Pautasso, 2008; Steck & Pautasso, 2008). Given that most species on the planet are invertebrates, for the regional positive species–people correlation to be a general biodiversity pattern, it also needs to apply to invertebrates.…”

Positive regional species–people correlations: a sampling artefact or a key issue for sustainable development?

“…Fjelds˚a, 2007;Pidgeon et al, 2007;Fjelds˚a & Burgess, 2008;Lepczyk et al, 2008;Moreno-Rueda & Pizarro, 2009). At the level of European countries, a positive species-people correlation was found for ants, aphids, grasshoppers and stream macro-invertebrates (Pautasso & Fontaneto, 2008;Schlick-Steiner et al, 2008;Steck & Pautasso, 2008;Pautasso & Powell, 2009), but the data did not allow the inclusion of sampling effort in those studies. Apart from invertebrates, species-rich groups such as bacteria and fungi have been almost completely neglected from the point of view of the large-scale correlation with people (Pautasso & Zotti, 2009;Nemergut et al, 2010).…”

The influence of different spatial-scale variables on caddisfly assemblages in Flemish lowland streams

“…Among the macroinvertebrates used for biological water quality monitoring Trichoptera, either separately or as part of the Ephemeroptera-Plecoptera-Trichoptera (EPT) taxa, have often received special attention in studies regarding the influence of environmental variables and human disturbance on species assemblages (Hall et al, 2001;Li et al, 2001;Solà & Prat, 2006;Haidekker & Hering, 2008;Pautasso & Fontaneto, 2008;Hering et al, 2009). This extensive use of Trichoptera is due to certain characteristics of this order.…”