Riparian zones and freshwater ecosystems: a new EU science-policy report

Cam Beck tree planting for the ‘Keeping Rivers Cool’ project. Image: Ribble Rivers Trust

Last week, we wrote about a new European Court of Auditors report which suggested that sustainable water management goals could be better integrated into the Common Agricultural Policy.  A recent joint BioFresh / REFRESH science policy brief discusses a similar topic: how riparian ‘buffer zones’ along waterways can help boost freshwater biodiversity conservation and restoration efforts in agricultural land, both now and in the future.

The policy brief outlines how restoring woodland, grassland and reedbeds in riparian areas – the strips of non-agricultural land that run alongside rivers – can help prevent fluctuations in water temperature, provide a range of wildlife habitat, stabilise river banks, help regulate flooding, and filter agricultural pollution and debris before it reaches the river.  As a significant proportion of Europe’s waterways lie in agricultural land, the process of conserving and restoring riparian buffer zones has the potential to improve the health and diversity of many of the continent’s freshwaters.

In particular, the brief outlines how woodland buffer zones may have an important role to play in mitigating the effects of potential climate warming on freshwater ecosystems by shading and cooling the water surface.  This  topic was investigated by Peter Brinkmann Kristensen and colleagues from Aarhus University in a 2013 journal article, and reported in a January 2014 REFRESH policy brief.

As a result, the joint BioFresh / REFRESH brief – published in April 2014 following the ‘Water Lives’ symposium – suggests that creating and restoring such riparian zones in agricultural land could strengthen adaptive planning for future climate change within the Water Framework Directive and potentially help bring freshwater conservation into the Common Agricultural Policy.

Keeping Rivers Cool

Understanding the role of riparian zones and other agri-environment schemes on freshwater ecosystems is a widely researched topic at present.  In Lancashire in North West England, the Ribble Rivers Trust are running a project called ‘Keep Rivers Cool‘ in conjunction with the Environment Agency.  At present, over 40,000 trees have been planted in riparian zones across the Ribble catchment, intended to shade and diversify the water’s edge and mitigate the effect of projected temperature increases on the river’s ecosystems.  Prolonged increases in water temperatures reduces the amount of oxygen in the water, which can result in widespread fish deaths.

Water Friendly Farming

Another collaborative UK research project ‘Water Friendly Farming’ involving the Freshwater Habitats Trust, the Game & Wildlife Conservation Trust, University of York and agrochemical company Syngenta has established a catchment-scale study of 25 farms across 30 km² of farmland in Leicestershire.

The study seeks to understand how different agri-environment schemes – such as riparian buffer zones, different soil and nutrient management schemes and bankside fencing to restrict livestock access  – influence freshwater biodiversity and ecosystem services at the catchment scale.  There are further details on this scheme in a leaflet here (pdf), and we’ll publish an interview with Jeremy Biggs from the Freshwater Habitats Trust at the end of the month.