Defining Recovery Potential in River Restoration: A Biological Data-Driven Approach

Martin A Wilkes,Alex J Dumbrell,Laura Allen,Mike Morris,Tom Lavers,Marco Van De Wiel,Morwenna Mckenzie,Marc Naura,Alessia Bani,Judy England,Craig Lashford

doi:10.3390/w13233339

Abstract

Scientists and practitioners working on river restoration have made progress on understanding the recovery potential of rivers from geomorphological and engineering perspectives. We now need to build on this work to gain a better understanding of the biological processes involved in river restoration. Environmental policy agendas are focusing on nature recovery, reigniting debates about the use of “natural” reference conditions as benchmarks for ecosystem restoration. We argue that the search for natural or semi-natural analogues to guide restoration planning is inappropriate due to the absence of contemporary reference conditions. With a catchment-scale case study on the invertebrate communities of the Warwickshire Avon, a fifth-order river system in England, we demonstrate an alternative to the reference condition approach. Under our model, recovery potential is quantified based on the gap between observed biodiversity at a site and the biodiversity predicted to occur in that location under alternative management scenarios. We predict that commonly applied restoration measures such as reduced nutrient inputs and the removal of channel resectioning could be detrimental to invertebrate diversity, if applied indiscriminately and without other complementary measures. Instead, our results suggest considerable potential for increases in biodiversity when restoration measures are combined in a way that maximises biodiversity within each water body.

Highlights

Through decades of progress by scientists and practitioners, the river restoration community has generated robust understanding of the physical processes involved in successful river restoration
Our results indicate that commonly applied restoration measures such as Overall, our results indicate that commonly applied restoration measures such as ririparian tree planting, reduced nutrient inputs and the removal of channel resectioning parian tree planting, reduced nutrient inputs and the removal of channel resectioning could could be detrimental to catchment-scale invertebrate biodiversity if applied indiscrimibe detrimental to catchment-scale invertebrate biodiversity if applied indiscriminately and nately and without other complementary measures
A shift towards greater integration of ecology in river restoration is being hindered by limited understanding of biological recovery potential

Summary

Introduction

Through decades of progress by scientists and practitioners, the river restoration community has generated robust understanding of the physical processes involved in successful river restoration. Detailed engineering guidance has been developed by key advisory bodies, such as the. Whilst these developments have achieved considerable success from an engineering perspective, the biological aspects of river restoration are less well understood. Many restoration projects fail to result in any detectable improvement in biodiversity despite demonstrably changing the abiotic environment [3,4]. We lack the ability to predict how biodiversity will respond to a range of alternative river restoration measures targeting hydrology, water quality and physical habitat

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Results

Discussion

Conclusion