Can we mitigate agricultural impacts on freshwater biodiversity and enhance ecosystem services at a landscape scale? First results from the Water Friendly Farming project, UK
Freshwater ecosystems in farmed landscapes, and the services they provide, are impaired by a wide range of stressors, from excess sediments and nutrients, to pesticides and physical simplification (Moss 2008, Ormerod et al. 2010). Many measures have been proposed to minimise these impacts, from buffer strips and constructed wetlands to river restoration and clean water pond creation, and there is now a large body of data on the effectiveness of such techniques at plot and field scales (e.g. Roni et al. 2008, Kay et al 2009, Pattison and Lane 2012). However, much less is known about the extent to which these measures work at larger scales although such information is vital for protecting freshwater biodiversity and ecosystem services more widely (Verdonschot et al. 2013). Specifically, many measures which show promise at small scale have not yet proved effective at larger scales (e.g. Bernhardt and Palmer 2011, Kay et al 2012). Possible reasons for this are that measures are: (i) more variable in their effectiveness than anticipated, (ii) not applied sufficiently comprehensively or (iii) have inherent flaws e.g. buffer strips are often bypassed by drains under them.
To provide data on the landscape scale effectiveness of measures intended to protect freshwaters, Pond Conservation and the Game & Wildlife Conservation Trust have established the ‘Water Friendly Farming’ research demonstration project. The aim of the project is to assess whether measurable improvements to freshwater biodiversity and ecosystem services can be detected when a full range of mitigation and enhancement measures are applied at a landscape scale, and as comprehensively as possible, in the farmed environment. The project therefore aims to provide a ‘reality check’ on the overall effectiveness of measures now being used in many areas.
The project uses a BACI design with three catchments, each of approximately 10 km2 in area, and including ponds, streams and ditches. Located in a typical lowland farming landscape in the English Midlands, a fundamental feature of the project is its extensive baseline, with three years pre-works monitoring (Fig 1). One catchment is a control with no measures applied, the second has only water resource protection measures (e.g. constructed wetlands, interceptions ponds) and the third has water resource measures plus habitat enhancement and creation techniques.
The paper will present the results of the baseline establishment phase including the first data describing between-year changes in the water quality and biodiversity of all waterbody types in a landscape (i.e. streams, ponds, ditches). Results also provide some of the first data on the full extent of water pollution in farmed landscapes, with around 95% of all surface waters impaired, and further confirm the exceptional importance of small waterbodies in terms of their biodiversity value in the agricultural landscape, with 85% of freshwater wetland plant species occurring in ponds (Fig 2).
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