Invertebrate traits for the biomonitoring of large European rivers: an initial assessment of alternative metrics

Abstract

Summary 1. The application of environmental policy and legislation across large‐scale administrative units creates a growing need for standard tools to assess and monitor the ‘ecological health’ of rivers, a requirement that can be achieved through the description of ecological functions of lotic invertebrate species in river communities. 2. To assess alternative metrics, we tested how the functional structure (described by 14 biological traits) of invertebrate communities in 190 large river reaches differed with respect to differences in taxonomic resolution (species, genus, family), taxa weighting of traits (raw abundance, ln‐transformed abundance, presence–absence data) and consideration of alien species (inclusion or exclusion), and how these differences influenced the potential of functional descriptions to discriminate river reaches across a gradient of multiple human impacts. 3. Functional descriptions derived at the level of species, genera and families were very similar, whereas functional descriptions derived from raw abundances differed significantly from those derived from both ln‐transformed abundances and presence–absence data. Functional descriptions after the exclusion of alien species differed considerably from those including alien species. 4. Generally, the functional descriptions significantly discriminated river reaches according to the level of human impact. Taxonomic resolution scarcely influenced the discrimination of impact levels, whereas the use of raw abundances decreased impact discrimination in comparison with ln‐transformed abundances and presence–absence data. Exclusion of alien species also decreased discrimination of impact levels. 5. When considered separately, individual biological traits describing maximal size, number of descendants per reproductive cycle, number of reproductive cycles per individual, life duration of adults, reproductive method, parental care, body form and feeding habits had the highest potential to discriminate the level of human impact. 6. Our findings indicate that genus or perhaps family identifications are sufficient for large‐river biomonitoring using invertebrate traits. Although raw abundances could provide a better discrimination of low levels of human impact, presence–absence data should be sufficient to discriminate functional community changes caused by elevated levels of human impact across Europe.

Taxonomic, phylogenetic and functional diversity of leeches (Hirudinea) and their suitability in biological assessment of environmental quality

“…Charvet et al (2000), Usseglio-Polatera et al (2000), and Gayraud et al (2003) indicate the enhanced usefulness of functional diversity in the biological assessment of different European watercourses when compared with other measures of diversity of benthic animals. Roque et al (2014) found noticeable differences between traditional diversity measures and distinctness in prediction abilities to different environmental variables.…”

Can biological invertebrate traits resolve effects of multiple stressors on running water ecosystems?

“…Among the c. 600 large river species of Europe, 76% had a complete and 18% an incomplete description of the 14 traits indicated in Table 1; the traits of 6% of the species (typically rare ones) could not be described (Gayraud et al, 2003). Because species-level information was so incomplete in the North American database, Vieira et al (2006) provided data on the availability of trait information for genera.…”

Seasonal variability in the Macroinvertebrate Community Index: Are seasonal correction factors required?

“…For each m aero invertebrate species, we documented 55 categories (modalities) of 15 biological traits in a similar manner to Usseglio-Polatera et al (2000) and Gayraud et al (2003). The selected traits reflected the life history of organisms, the resilience or resistance potential beyond that of life history traits, and general biological and physiological features (see Dolédec et al 2006).…”

“…Key life history, physiological and behavioural characteristics of stream invertebrates (or species traits) can be used to describe the functional structure of a stream community, based on taxa abundances and an array of biological traits describing size, reproductive characteristics, mobility, body form, and feeding habits (Charvet et al 1998(Charvet et al , 2000Gayraud et al 2003). Analysis of community responses to disturbance based on species traits offers an alternative or complementary approach to community structure for assessing disturbance responses in stream communities (Corkum & Ciborowski 1988;Poff & Allan 1995;Poff 1997;Lamouroux et al 2002;Dolédec et al 2006).…”