Riverside meadows associated with meandering river channels

Overall vulnerability

Feature assessed:

• Riverside meadows associated with meandering river channels

Special qualities:

• Beautiful views created by contrasting landscapes and dramatic geology

Feature description:

Riverside meadows are characterised by meandering river channels in a flat alluvial floodplain. This distinctive feature includes grazing meadows often with an area of wet grassland. At the water’s edge there are sometimes hedgerow trees that can be scattered or quite dense.

This landscape character type exists along rivers throughout the PDNP. In the Dark Peak Western Fringe, meadows are found along the River Etherow and further south along the River Goyt. In the Derwent valley the riverside meadows are part of a narrow strip of floodplain that runs next to the river and is either one to two fields wide. It stretches continuously from below the Ladybower reservoir on the River Derwent, taking in Hope on the River Noe, Bakewell on the River Wye and running to Matlock just outside the PDNP boundary.

How vulnerable are riverside meadows associated with meandering river channels?

Riverside meadows associated with meandering river channels in the PDNP have been rated ‘very high’ on our vulnerability scale. This score is due to high sensitivity and exposure to climate change variables, coupled with a variable current condition and a low adaptive capacity.

The extent of riverside meadows has been reduced over the last century with the ecological quality affected at many sites. Extreme weather conditions leading to both flooding and drought could have a significant impact on this feature. The adaptive capacity of river meadows is limited and there is no central organisation with responsibility for their condition.

Current condition:

Changes to agricultural practices since the Second World War have affected the riverside meadows that are associated with winding river channels. There has been a reduction in the number of wet pastures and flood meadows, which provided ecological diversity and were potential resources to help with flood alleviation. The deliberate drainage of such areas has probably been a major factor in causing increased flash flooding in addition to reducing their value as wetland habitat.

What are the potential impacts of climate change?

Overall potential impact rating

Direct impacts of climate change

Climate change could have a significant impact on riverside meadows, and remaining wetlands could be at risk of disappearing. Extremes of wetness and drought can both have a negative impact, and in fact, wetland communities can be more susceptible to frequent flooding than to drought. Such change could alter riverside meadow habitats in terms of their hydrology and the composition of species present. Data Certainty: High Temperature change, in particular hotter summers, are likely to be a threat to the variety of habitats found in riverside meadows, through changes in growing conditions for meadow and wetland plants. As a result, the species composition of riverside meadows is likely to change. Hotter temperatures may mean plant phenology changes significantly - for example, flowering and seed setting taking place earlier in the season. Data Certainty: Moderate Extreme storm events may lead to an increase in the rapidity of some natural river processes, with meanders being cut off to form oxbow lakes particularly in the more sinuous stretches. This could increase the habitat and wildlife value of such areas. Data Certainty: Low

Human behaviour change

Riverside meadows are sensitive to any change in water levels and water availability. Drier summer conditions may affect both as water abstraction increases. This may result in a change in plant composition - with a rise in abundance of species associated with drier conditions, and a decrease in that of wetland species. Data Certainty: Moderate If flooding becomes more frequent in winter and summer during extreme events, it may alter the economic viability of agriculture in these areas. This could result in either increased intensification of management, or conversely the abandonment of some areas. If winter access becomes difficult, grazing levels may change. There could also be an increase in demand to use such areas for temporary storage of floodwater. Data Certainty: Moderate

A drive to generate renewable energy as part of carbon reduction schemes may mean that river channels or soughs - historic mine drains that run into rivers - are utilised and fitted with micro hydroelectric generators. This could result in water being diverted or channels modified. The addition of reservoirs into these landscapes is also a possibility. Such changes could have a negative impact not just on the aesthetic value of the area but also its ecological function. Data Certainty: Moderate

Hotter summers could increase pressure on recreational sites near water that also offer shade. An increase in the number of walkers and anglers, for example, may put pressure on infrastructure such as footpaths. This could in turn increase the risk of disturbance to wildlife such as water voles or some breeding birds. Hotter summers and a longer growing season may in turn affect agricultural practices, changing stock management if ground conditions become suitable for intensive grazing or perhaps conversion to arable land. Both these scenarios would be detrimental to the river system, water quality and aesthetics of the landscape. Data Certainty: Low

Invasive or other species interactions

A longer growing season due to warmer winters, coupled with changes to rainfall patterns may result in non-native species being able to colonise new areas and expand their range. This may mean that specialist wetland plant species lose out to species that are more adaptable to drier or fluctuating conditions. Ultimately, this could mean that certain native species are lost and replaced by non-native species, for example New Zealand pygmy weed. Data Certainty: Moderate

Changes in rainfall patterns and an increase in storm event frequency and severity are likely to disturb floodplain and riverbank soils, leading to a rise in colonisation opportunities for non-native species. Certain native species may be lost as a result. Data Certainty: Moderate Riparian invasive plant species may also come to dominate areas of wet grasslands. Data Certainty: Low

Nutrient changes or environmental contamination

Heavy rainfall and more frequent flooding events could lead to increased levels of phosphorus in floodplain soils and an increased risk of pollution. This could alter the composition of the plant community in riverside meadows with valued species lost and the habitat moving towards less valued inundation grassland. Data Certainty: High

There could be further changes in plant community composition and habitats if the amount of nitrogen in the water increases as result of higher temperatures and reduced dilution during periods of low flow. In wetter meadows, nitrogen input from groundwater and floodwater could favour less desirable but more competitive plant species to the detriment of slower growing species that make up semi-natural meadow communities. Data Certainty: Moderate

Sedimentation or erosion

Riverside meadows and their associated infrastructure such as footpaths, historic field barns and mills are susceptible to both flooding and silt deposition. A rise in heavy rainfall events damage these features and riverside trees could be lost, further increasing the risk of erosion. Siltation could affect the species composition of wetland plant communities. Data Certainty: Moderate

What is the adaptive capacity of riverside meadows associated with meandering river channels?

Overall adaptive capacity rating

This is a highly fragmented set of features. Although there is some connectivity through the river channels, these riverside meadows are geographically specific – tied to wide, flat floodplains. This will present difficulties for riverside meadow species to move northwards or to higher altitudes in order to preserve the current character of the feature within the PDNP. Although the geological landform will remain, the habitats and species found in these areas are very likely to change. Data Certainty: Very High

Areas categorised as riverside meadows share key characteristics: a flat alluvial river corridor; meandering river channel with shingle beds and marginal vegetation; seasonally waterlogged alluvial soils; grazing meadows, often with patches of wet grassland and dense waterside and scattered hedgerow trees. There is limited diversity between the small number of sites in the PDNP, and this similarity will restrict the adaptive capacity, as the low variation means similar impacts will be experienced across the PDNP. Data Certainty: Very High

Grazing marshes may be less sensitive to atmospheric deposition of pollution than some other habitat types, although there is poor information available. The most sensitive areas are likely to be those close to channels, which may be less able to recover from change than areas further away. Data Certainty: Low

Currently there are some environmental stewardship options available that could help increase the adaptive capacity of riverside meadows. These include “Maintenance of species-rich semi-natural grassland”, “Restoration of species-rich semi-natural grassland” and “Wetland grazing”. Management which increases the quality of the current habitat will also increase its resilience to change in the future. However, the future of environmental land management schemes is highly uncertain. Data Certainty: Very High

No central organisation is responsible for the condition of riverside meadows in the PDNP. While the PDNPA management plan can recommend management options to improve condition and thus increase resilience, it has limited power to implement them. River catchment partnerships such as Derbyshire Derwent Catchment Partnership and the Upper Mersey Catchment Partnership are however a resource to influence positive management of floodplains. Data Certainty: Low It is likely that management options aimed at tackling non-climate effects can only ever have a limited impact, and so could only partially offset climate impacts. Data Certainty: Low

Key adaptation recommendations for riverside meadows associated with meandering river channels:

Improve current condition to increase resilience

The current condition of a feature is an important factor alongside its sensitivity and exposure, in determining its vulnerability to climate change. These recommendations are aimed at improving the condition of the feature at present, therefore making it better able to withstand future changes to climate.

• Look to improve the quality and species diversity of these grasslands through sensitive and flexible grazing and by limiting inputs of fertilizers and pesticides.
• Put protections in place to ensure hydroelectric generators are not installed in inappropriate locations where they would be detrimental to the function of the river system and the aesthetics of the landscape.
• Ensure tree strips along riversides are protected as much as possible in order to minimise the effects of erosion due to higher flows.
• Consider the impact on key views when planning adaptations.

Improve current condition to increase resilience: Targeted conservation efforts for important sites and at risk areas

The current condition of a feature is an important factor alongside its sensitivity and exposure, in determining its vulnerability to climate change. These recommendations are conservation measures aimed at those sites that will have the biggest impact for this feature – either because they are particularly important for the feature or because they are most at risk from climate change.

• Investigate the flood storage capacity of riverside meadows. Identify areas that could benefit from becoming temporary flood storage areas during times of high flow.

Improve current condition to increase resilience: Increase structural diversity to improve resilience at a landscape scale

The current condition of a feature is an important factor alongside its sensitivity and exposure, in determining its vulnerability to climate change. These recommendations focus on increasing the structural diversity of the area or habitat in which the feature is found. This can help to offset the effects of climate change on the feature, as well as to allow it to be in a better position to recover from future climate changes.

• Allow natural river processes such as the formation of oxbow lakes to occur as much as possible and avoid channel modifications. Accept changes to feature These recommendations are about adapting ways of thinking to be accepting of inevitable change. While some changes may be negative, this also presents a chance to seek out any positive opportunities that may be caused by climate change.
• The potential for new reservoirs should be raised as an issue in the review of the Local Plan for the PDNP where this supports climate change adaptation, nature recovery and effective visitor management.