Next Article in Journal
Application of Set Pair Analysis-Based Similarity Forecast Model and Wavelet Denoising for Runoff Forecasting
Previous Article in Journal
An Estimate of Energy Available via Microbial Sulfate Reduction at a Quaternary Aquifer in Northern Japan considered for Low Temperature Thermal Energy Storage
Article Menu

Export Article

Open AccessArticle
Water 2014, 6(4), 868-911; doi:10.3390/w6040868

Aquatic Plant Dynamics in Lowland River Networks: Connectivity, Management and Climate Change

1
The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, Scotland, UK
2
General Ecology, Faculty of Environmental Sciences and Process Engineering, Brandenburg University of Technology Cottbus-Senftenberg, PO Box 101344, Cottbus 03013, Germany
3
Department of Biology, University of Leicester, Leicester LE1 7RH, England, UK
4
IBL Umweltplanung GmbH, Bahnhofstraße 14a, Oldenburg 26122, Germany
*
Author to whom correspondence should be addressed.
Received: 30 January 2014 / Revised: 18 March 2014 / Accepted: 31 March 2014 / Published: 9 April 2014

Abstract

The spatial structure and evolution of river networks offer tremendous opportunities to study the processes underlying metacommunity patterns in the wild. Here we explore several fundamental aspects of aquatic plant biogeography. How stable is plant composition over time? How similar is it along rivers? How fast is the species turnover? How does that and spatial structure affect our species richness estimates across scales? How do climate change, river management practices and connectivity affect species composition and community structure? We answer these questions by testing twelve hypotheses and combining two spatial surveys across entire networks, a long term temporal survey (21 consecutive years), a trait database, and a selection of environmental variables. From our river reach scale survey in lowland rivers, hydrophytes and marginal plants (helophytes) showed contrasting patterns in species abundance, richness and autocorrelation both in time and space. Since patterns in marginal plants reflect at least partly a sampling artefact (edge effect), the rest of the study focused on hydrophytes. Seasonal variability over two years and positive temporal autocorrelation at short time lags confirmed the relatively high regeneration abilities of aquatic plants in lowland rivers. Yet, from 1978 to 1998, plant composition changed quite dramatically and diversity decreased substantially. The annual species turnover was relatively high (20%–40%) and cumulated species richness was on average 23% and 34% higher over three and five years respectively, than annual survey. The long term changes were correlated to changes in climate (decreasing winter ice scouring, increasing summer low flows) and management (riparian shading). Over 21 years, there was a general erosion of species attributes over time attributed to a decrease in winter ice scouring, increase in shading and summer low flows, as well as a remaining effect of time which may be due to an erosion of the regional species pool. Temporal and spatial autocorrelation analyses indicated that long term hydrophyte biomonitoring, for the Water Framework Directive in lowland rivers, may be carried out at 4–6 years intervals for every 10 km of rivers. From multi-scale and abundance-range size analyses evidence of spatial isolation and longitudinal connectivity was detected, with no evidence of stronger longitudinal connectivity (fish and water current propagules dispersal) than spatial isolation (bird, wind and human dispersal) contrary to previous studies. The evidence for longitudinal connectivity was rather weak, perhaps resulting from the effect of small weirs. Further studies will need to integrate other aquatic habitats along rivers (regional species pool) and larger scales to increase the number of species and integrate phylogeny to build a more eco-evolutionary approach. More mechanistic approaches will be necessary to make predictions against our changing climate and management practices. View Full-Text
Keywords: autocorrelation; richness; turnover; diversity; evenness; abundance; species range-abundance patterns; species traits; competition; weed-cutting autocorrelation; richness; turnover; diversity; evenness; abundance; species range-abundance patterns; species traits; competition; weed-cutting
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License (CC BY 3.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Demars, B.O.; Wiegleb, G.; Harper, D.M.; Bröring, U.; Brux, H.; Herr, W. Aquatic Plant Dynamics in Lowland River Networks: Connectivity, Management and Climate Change. Water 2014, 6, 868-911.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Water EISSN 2073-4441 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top