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

Abstract

-Different components of biological diversity of leeches (Hirudinea), sampled in lowland watercourses in Poland were compared between sites differed in terms of environmental quality, measured by officially approved procedures. Indices based on taxonomic diversity, rarefied species richness, taxonomic distinctness, phylogenetic diversity and functional diversity were considered in the analysis, for sites belonging to three biocoenotic types of watercourses. In most cases values of all indices except Pielou's evenness show unimodal relationships with environmental quality and in any case monotonic increase in diversity was not shown. Median values of diversity were significantly higher and its highest values were significantly more frequent at sites with moderate than with low or high environmental quality. This pattern of relationships was observed both for indices based on presence/absence data and those based on relative abundance of species. The significance of this mode of relationships differed between biocoenotic types and between procedures using to measure environmental quality. The results obtained show low and doubtful usefulness of each component of leech diversity as an element of biological assessment in lowland watercourses.Keywords: taxonomic diversity / phylogenetic diversity / functional diversity / Hirudinea / biological assessment Résumé -Diversité taxonomique, phylogénétique et fonctionnelle des sangsues (Hirudinea) et leur aptitude à l'évaluation biologique de la qualité environnementale. Différentes composantes de la diversité biologique des sangsues (Hirudinea), échantillonnées dans les cours d'eau de plaine en Pologne, ont été comparées entre des sites différents en termes de qualité environnementale, mesurée par des procédures officiellement approuvées. Les indices fondés sur la diversité taxonomique, la richesse en espèces raréfiées, la diversité phylogénétique et la diversité fonctionnelle ont été pris en compte dans l'analyse, pour des sites de cours d'eau appartenant à trois types biocénotiques. Dans la plupart des cas, les valeurs de tous les indices, à l'exception de l'équitabilité de Pielou, montrent des relations unimodales avec la qualité de l'environnement et, en tout état de cause, une augmentation monotone de la diversité. Les valeurs médianes de la diversité étaient significativement plus élevées et les valeurs les plus élevées étaient significativement plus fréquentes dans les sites de qualité environnementale modérée plutôt que faible ou élevée. Ce patron de relations a été observé à la fois pour les indices fondés sur les données de présence/ absence et ceux fondés sur l'abondance relative des espèces. L'importance de ce mode de relations différait entre les types de biocénoses et entre les procédures utilisées pour mesurer la qualité de l'environnement. Les résultats obtenus montrent que chaque composante de la diversité des sangsues est peu utile et douteuse en tant qu'élément de l'évaluation biologique dans les cours d'eau de plaines.Mots-clés : diversité taxo...

Phylogenetic diversity of larval Chironomidae (Diptera) in lowland rivers as a potential tool in assessment of environmental quality

“…This type of relationships excludes both traditional indices of species diversity and both indices of taxonomic distinctness from useful predictors of environmental quality. A similar pattern of distribution was also found in the relationships between disturbance or the level of degradation and taxonomic diversity of, e.g., benthic fauna in streams (Townsend et al, 1997), riverine insect larvae (Fore et al, 1996) and riverine Hirudinea (Koperski, 2017). Taxonomic diversity of all these groups is clearly lower at high than at moderate values of environmental quality.…”

“…Well-known and commonly used indices of phylogenetic diversity were applied to develop index ChiPDi: quadratic entropy (Pavoine et al, 2005;Koperski, 2017) and total phylogenetic distance (e.g., Allen et al, 2009;Koperski & Meronka, 2017). Different types of taxonomic richness of benthic animals (species richness, family richness) have been found as a metrics strongly correlated with the disturbance in streams (e.g., Compin & Cereghino, 2003;Englund et al, 2007).…”

“…Different types of taxonomic richness of benthic animals (species richness, family richness) have been found as a metrics strongly correlated with the disturbance in streams (e.g., Compin & Cereghino, 2003;Englund et al, 2007). Another commonly used index, Mean Phylogenetic Distance (Webb, 2000;Koperski, 2017) was rejected after preliminary analyzes because it did not show any correlation with MMI values. Presented index ChiPDI seems to be an efficient measure of environmental quality expressed by index MMI, more effective that other tested measures of diversity.…”

“…Additionally, the application of traditional taxonomic diversity indices (e.g., Shannon, Margalef, Simpson) in freshwater biological assessment frequently seems inadequate (Lydy et al, 2000). In some cases, traditional indices of taxonomic diversity are not suitable for the purposes of biological assessment because of unimodal (hump-like) distribution of their values along with the gradient of ecological disturbance (Bini et al, 2014;Koperski, 2017). This type of response makes it difficult to distinguish the values of diversity indices at high values of ecological quality from those at low values (De Pauw & Vanhooren, 1983;Barbour et al, 1999) Commonly, assessment of benthic invertebrate diversity contains mixed-level taxonomic identification or species-level identification of selected taxa with high indicative value (Bailey et al, 2001).…”

“…Well-known diversity indices, currently used as metrics in biological assessments of environmental quality, were compared with phylogenetic indices in terms of their explaining value being a measure of their potential suitability. Indices based on phylogenetic relationships are expected to correlate better with environmental quality than indices based on taxonomy and taxonomic distinctness as in the case of Hirudinea (Koperski, 2017). If that is the case, phylogenetic distance (PD) indices could be considered as a better tool to discriminate sites classified in different environmental quality classes.…”