Abstract
Hydromorphological alterations influence a wide range of environmental conditions as well as riparian vegetation and the structure of the macroinvertebrate community. We studied relationships between the structure and diversity of the macroinvertebrate community and hydromorphological and other environmental conditions in the river Gradaščica (central Slovenia). The Gradaščica river is a pre-Alpine torrential river that has been morphologically altered by humans. A selection of abiotic factors was measured, the ecomorphological status of the river was assessed, vegetation in the riparian zone was surveyed and benthic macroinvertebrates were sampled. Correlations between diversity and the structure of the macroinvertebrate community, environmental parameters and occurrence of invasive alien plant species in the riparian zone were identified. The significance of the influence of environmental parameters on the structure of the macroinvertebrate community was examined. We found that hydromorphological alterations in the river have had a significant influence on the diversity and composition of the macroinvertebrate community because of changes of flow velocity and the spread of invasive alien plant species that has followed those changes. Factors that also significantly influence the composition of macroinvertebrate community are distance from the source and conductivity. Our findings suggest minimization of further human hydromorphological changes of watercourses could prevent the loss of biodiversity of riverine ecosystems.
Highlights
Stream ecosystems harbor exceptional levels of biodiversity, despite their small spatial coverage of the Earth’s surface [1]
RCE(2–4) scores evaluating the alteration of the riparian zone were found to be significantly higher (p < 0.029) on reference sites (REF) than on most modified sites (MO) and significantly higher than on sites upstream dams (UD) (p < 0.035) and downstream dams (DD) (p < 0.033)
Our results confirm the hypothesis that morphological alterations have a negative influence on the diversity of both riparian vegetation species and the macroinvertebrate community
Summary
Stream ecosystems harbor exceptional levels of biodiversity, despite their small spatial coverage of the Earth’s surface [1]. Morphological alterations include changes of the banks removing of riparian vegetation and various alterations of the riverbed, such as dams or reinforcements with concrete and/or rocks, all of which negatively influence the biodiversity [7]. Numerous dams have been built to manage the flow, but the subsequent accumulation of water is accompanied by accumulation of sediment, nutrients and pollutants, such as metals [8]. Dams disrupt the longitudinal pattern of riverine communities [9], since they impede the transport of organic matter and biota, influencing the species richness and health of the river ecosystem [10,11]. Surface-release dams raise the temperature of the water downstream by increasing both the residence time of water and the surface area of water exposed to
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
