Relationships between taxonomic resolution, macrobenthic community patterns and disturbance

Abstract

Although analyses of macrobenthic infaunal communities traditionally require identification of the organisms to the species level, there is still only a limited number of studies which have examined the use of higher-level taxa in monitoring surveys. These generally indicate that identification of organisms to the lowest possible taxon may not always be necessary to enable description of spatial patterns in routine environmental and pollution monitoring programs. In other fields of marine ecology, such as studies of biodiversity, comparative investigations over large geographical areas, and the development of rapid-assessment techniques, the use of identification to higher taxonomic levels is often necessary. Detailed comparative studies of faunal patterns at various taxonomic levels are therefore important. This study uses multivariate analyses of macrofauna and environmental data from 20 separate investigations in the Skagerrak and North Sea to examine faunal patterns at different taxonomic levels. Data are analysed at the levels of species, genus, family, order, class and phylum. Transformation of data is also considered since degree of tlansforrnation is as important in determining the outcome of subsequent analyses as the taxonomic level to whlch organisms are Identified. Correlations between the underlying similarity matrices at the species level and higher taxonomic levels show highest values in polluted areas, lower values in less disturbed areas and lowest values in pnstine areas, indicating that the faunal patterns for the various taxonomlc levels become more similar as the degree of disturbance increases. For those areas where time-senes data are available it is shown that, as contamination increases, correlations between the faunal patterns at all taxonomlc levels, but especially the highest levels, and the environmental variables tend to increase, and after several years of contamination all the correlations are high, independent of taxonomic level. Again, the faunal patterns at the different taxonomic levels tend to become more s~milar as a result of increased pollution For all 20 investigations, highest correlations between faunal patterns (i.e. the underlying similarity matrices) and environmental variables were mainly found at the levels of species, genus and family, and often there was a distinct drop in correlation value between family and order In most cases, ~ndependent of the level of pollution, there is only a minor reduction in correlation between species and family, suggesting that identification to the level of family may be satisfactory in many routine monitonng surveys. The debate about the level of taxonomic resolution required for routine environmental monitoring becomes relatively unimportant if the effects of choosing different transformations are not also considered.

Evaluating community–environment relationships along fine to broad taxonomic resolutions reveals evolutionary forces underlying community assembly

“…Accordingly, the concept of taxonomic surrogacy or sufficiency (that is, using broadly resolved taxonomic data as a substitute for species-level data) has been subjected to extensive examination in bioassessment studies (Warwick, 1993;Bailey et al, 2001;Terlizzi et al, 2003). Despite some controversial opinions about general applications for particular organisms and ecosystems, the use of broadly resolved data (that is, genus-, family-or even phylum-level classification) has been demonstrated to portray similar community-scale responses to environmental variability as specieslevel data in many empirical studies (Olsgard et al, 1998;Heino and Soininen, 2007;Heino, 2008;Bhusal et al, 2014;Heino, 2014).…”

“…In contrast, habitat differentiation between closely related taxa (Debussche and Thompson, 2003) and/or convergent evolution between distinctly related taxa (Cavender-Bares et al, 2004) is likely to be vital in those cases, which fail to detect ecologically meaningful patterns using broadly resolved data. Review of some earlier studies (Olsgard et al, 1998;Heino and Soininen, 2007;Heino, 2008;Bhusal et al, 2014;Heino, 2014) suggests that varying the taxonomic resolution of composition data exerts an influence on the strength (usually quantified as explained variance R 2 ) of community-environment relationships, with the best taxonomic resolution differing for various targeted organisms and/or study regions. Thus, there are a variety of potential mechanisms by which taxonomic resolution may influence the strength of community-environment relationships.…”

Patterns of distribution of annelids: taxonomic and spatial inconsistencies between two biogeographic provinces and across multiple spatial scales

“…Small-scale local processes, such as competition or predation, are likely to cause variation in populations of individual species at scales of centimetres to 100s of metres (Underwood & Chapman 1996). Largescale processes, such as historical events, biogeography, or effects of average temperature, may be readily identifiable as changes in taxa grouped into genera or families (Levin 1992) because large amounts of small-scale variability among individual species are generally thought to flatten or average out as data are accumulated over larger scales and longer times (Warwick 1988, Anderson et al 2005 such that impacts are manifest at higher taxonomic levels (Ferraro & Cole 1990, Olsgard et al 1998.…”

“…Such studies have generally tested hypotheses about entire assemblages of organisms and have found that the level of taxonomic identification did not affect the ability to detect differences among sites, largely due to the redundancy of much of the data in multivariate analyses (Warwick 1988, Olsgard et al 1998. Many previous studies that used univariate analyses were also interested in hypotheses about assemblages where multivariate data were converted into univariate diversity indices (e.g.…”

Implications of taxonomic modifications and alien species on biological water quality assessment as exemplified by the Belgian Biotic Index method

“…On top of that, information loss when identifying to genus or even family level is often small, and according to several authors it is therefore not necessary to descend to the species level (e.g. Warwick, 1988;Bowman & Bailey, 1997;Ghetti, 1997;Olsgard et al, 1998;Dole´dec et al, 2000;Gayraud et al, 2003). Another problem associated with species level identifications is the increasing uncertainty that arises with an increasing level of detail.…”