Year-end Sale % OFF 
Abstract
AbstractAimTo investigate if connectivity and zebra mussel (Dreissena polymorpha) occurrence can mitigate effects of eutrophication in a lowland lake landscape.LocationUpper Lough Erne, Northern Ireland, UK.MethodsData on environment, macrophytes and invertebrates were assembled for three basins of a large central lake and its satellite floodplain lakes via field surveys and palaeolimnological analyses. Space–time interaction analyses of palaeoecological data were compared pre‐1950 and post‐1950. Multivariate analyses examined how connectivity, environment and zebra mussels influenced contemporary lake communities, and explain their divergence from historical communities in the past.ResultsPre‐1950, we found high community variation across sites and low within‐lake variation in macrophytes, but progressive eutrophication accentuated within‐lake community variation after 1950. Partitioning analysis showed larger effects of connectivity than nutrient enrichment on contemporary macrophyte composition, while local effects structured invertebrate communities. Three clusters of lakes were revealed according to variation in macrophyte composition, isolation from the central lake and nutrient enrichment: Group 1– the central lake and six nearby lakes were meso‐eutrophic (TP = 66.7 ± 47.6 μg/L; TN = 0.79 ± 0.41 mg/L) and had the highest zebra mussel abundances and organismal biodiversity; Group 2– Eight eutrophic (TP = 112±36.6 μg/L; TN = 1.25 ± 0.5 mg/L) and connected lakes; Group 3– Seven isolated and hypertrophic (TP = 163.2 ± 101.5 μg/L; TN = 1.55 ± 0.3 mg/L) lakes. Pre‐1950 palaeolimnological data for macrophytes and invertebrates for 5 lakes and a basin in the central lake most resembled extant lake communities of Group 1. However, palaeo‐records revealed that macrophytes and invertebrates subsequently converged towards those of Groups 2 and 3.Main conclusionsOur study reveals that the central “mother” lake acts as a hub for preserving biodiversity via shared hydrological connectivity with satellite lakes and high zebra mussel abundances. These may buffer the impoverishing effects of eutrophication and sustain unexpectedly high biodiversity in the short term. Such protective buffering, however, cannot be relied upon indefinitely to conserve biodiversity.
Highlights
Floodplain lake systems are characterized by variable environmental and fluvial dynamics that create complex habitats and connectiv‐ ity gradients (Ward, Tockner, & Schiemer, 1999)
Main conclusions: Our study reveals that the central “mother” lake acts as a hub for preserving biodiversity via shared hydrological connectivity with satellite lakes and high zebra mussel abundances
The analysis identified water colour, plant coverage and one Asymmetric Eigenvector Maps (AEM) (AEM10 of the water flow model) as factors contributing to variation in invertebrate composition
Summary
Floodplain lake systems are characterized by variable environmental and fluvial dynamics that create complex habitats and connectiv‐ ity gradients (Ward, Tockner, & Schiemer, 1999). The system supports relatively high macrophyte diversity This led us to hypothesise that connectivity and invasion by zebra mussels have delayed biological degradation that would be expected to arise from nutrient enrichment. Zebra mussels can affect nutrient stoichiometry and phytoplankton composition with important positive consequences for macrophytes and water column turbidity (Zhu, Fitzgerald, Mayer, Rudstam, & Mills, 2006) To our knowledge this represents the first study to ex‐ plicitly combine present‐day and historical data to test how eutro‐ phication, biological invasion and hydrological connectivity jointly influence biodiversity and ecosystem resilience in space and time
Sign-in/Register to view highlights & summary 
Published Version (
Free)
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.
