Tools for bioindicator assessment in rivers: The importance of spatial scale, land use patterns and biotic integration

• Published in: Ecological indicators 2013-11, Vol.34, p.460-477
• Main Authors: Cortes, Rui Manuel Vitor, Hughes, Samantha Jane, Pereira, Vitor Rodrigues, Varandas, Simone da Graça Pinto
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Applied ecology; Bioindicator; Biological and medical sciences; Conservation, protection and management of environment and wildlife; data collection; Environmental predictors; environmental quality; eutrophication; forest types; Fresh water ecosystems; functional diversity; Fundamental and applied biological sciences. Psychology; General aspects; land use; Land use metrics; least squares; linear models; lotic systems; Macroinvertebrate metrics; macroinvertebrates; monitoring; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; rivers; spring; streams; Synecology; Traits; urbanization; watersheds
• ISSN: 1470-160X; 1872-7034
• DOI: 10.1016/j.ecolind.2013.06.004

•We outline a sequence of analyses to identify environmental variables that drive change in biological quality elements.•Niche breadth is used to assess candidate bioindicator response, avoiding bias resulting from expert judgement.•Methodology was tested on different levels and forms of macroinvertebrate data.•Fractal and nonfractal land use metrics were important determinants of ecological status.•Results revealed a strong association between invertebrate traits and environmental predictors. This study outlines an alternative, versatile and flexible procedure to the Assessment System for the Ecological Quality of Streams and Rivers throughout Europe using Benthic Macroinvertebrates (AQEM) protocol for selecting and assessing candidate bioindicators for Water Framework Directive (WFD) compliant monitoring programmes. Based on different forms of benthic macroinvertebrate data using relative abundance of family level taxonomic groups, metrics and traits collected during spring 2010 at 96 lotic sites across northern Portugal, the procedure employs components of top down and bottom up analytical processes and introduces the concept of niche breadth to assess biological quality element response to environmental and stressor parameters across different spatial levels. Random Forest classification revealed that fractal and non-fractal land use metrics at basin and local level were extremely important determinants of Water Framework Directive determination of “Good” ecological quality, particularly at the local scale. The amount of urbanization at the lower spatial level was a particularly important determinant of ecological quality, while the extent and type of forest (especially coniferous) was more important at higher, river basin scale. Distance-based linear models (DISTLM) and distance-based redundancy analysis (dbRDA) were used to determine associations between invertebrate data and non-redundant environmental predictors selected using the Akaike Information Criterion (AIC). Results revealed a stronger association between invertebrate traits and selected environmental predictors compared to the other types of invertebrate data, although some association between invertebrate relative abundance and eutrophication was detected. Principal Components Analyses (PCA) were run for the non-redundant sets of predictors for each macroinvertebrate data set to extract an environmental quality gradient along the first axis. Niche breadth, calculated for candidate indicat