Epsilon Archive for Student Projects

Abstract

This study evaluated the effect of agricultural ditch rehabilitation using a two-stage
design on water quality and the composition of functional traits in aquatic
macroinvertebrate communities. Nineteen paired sites in southern and central
Sweden were analysed, each with a remediated downstream section and an
unremediated upstream section.
No statistically significant differences were found in the physicochemical
parameters analysed, although the remediated sections had lower maximum values
and less dispersion for several pollutants. Likewise, traditional taxonomic
indicators such as richness, total abundance and metrics based on Ephemeroptera,
Plecoptera and Trichoptera (EPT) also showed no clear differences between
conditions.
However, functional analysis identified nine traits with a high contribution to
functional dissimilarity. Intermediate body size showed a positive relationship with
total phosphorus and a negative relationship with suspended solids. Significant
associations were also observed between life cycle duration traits (short and long)
and turbidity, suggesting reproductive responses to conditions of increased
sedimentation.
These results suggest that, although no overall improvements in water quality and
taxonomy were detected, the analysis of functional traits highlighted ecological
signals that conventional metrics overlooked in this dataset. Therefore,
incorporating this complementary approach into monitoring programmes could
improve the ecological assessment of restoration interventions in agricultural
landscapes.