Monitoring wetlands
Habitat and Botanical Surveys
The New Forest’s wetland habitats are among the most ecologically significant in the UK.
Over two-thirds of all UK wetland plant species can be found here – around 300 species – while 30 per cent of England’s threatened freshwater species depend on these habitats.
The area contains the largest lowland valley mire complex in the UK, recognised as being of European and international importance.
Restoration is needed as many wetlands in the New Forest have been degraded over time by drainage and other human interventions.
Restoration work aims to reverse these impacts and allow natural wetland processes to function once again.
Measuring success
To assess how successful this work is, FE maps habitats before and after restoration. However, because New Forest wetlands are so distinctive, they do not always fit standard habitat classifications.
To address this, the Freshwater and Wetland Restoration Plan sets out detailed descriptions of New Forest wetland habitats in their optimal, undisturbed condition.
These act as benchmarks to help us judge how well restored areas are recovering.
Alongside habitat mapping, detailed botanical surveys are carried out to understand the extent and quality of recolonising vegetation.
These surveys reveal whether characteristic New Forest wetland plant communities are returning, expanding, and functioning naturally.
Developing a robust monitoring approach
Forestry England commissioned Footprint Ecology to trial these monitoring methods on previously restored sites (see case studies below).
This work successfully refined a comprehensive approach to tracking habitat recovery.
Using this approach, all wetland sites restored last year have now been surveyed, creating a baseline for long-term monitoring.
Follow-up surveys will show how well each site is responding to restoration and help guide future work.
Geomorphology
Measuring the physical characteristics of rivers and wetlands helps us understand how these systems have been altered and whether they are functioning as naturally as they should. This information not only guides what type of restoration is needed, but also allows us to assess whether completed restoration work has improved the condition of the site. Forestry England has developed a comprehensive, bespoke geomorphological survey programme to monitor its wetland restoration work. These surveys look at both the channel and the riparian edge to assess how they interact with each other.
The Noads Mire
The Noads Mire is one example of how geomorphological surveys work in practice during New Forest habitat restoration.
In the past, artificial drainage channels caused water to flow too quickly through the mire, leading to erosion. Restoration work has helped create a more natural watercourse, allowing water to spread more gently across the landscape.
Work first took place between 2017 and 2020. The artificial drain was filled in and the bed level raised so that water could flow as a shallow stream. Heather bales and locally dug gravel, known as hoggin, were used to reshape the channel, while material from nearby spoil banks was spread across the site to reconnect the stream with its floodplain.
Further work downstream returned the watercourse to its original route, where traces of old meanders remained. Recovery was initially slower than expected due to thin soils, limited vegetation and heavy rainfall soon after the work.
Repairs were carried out in 2022 to stabilise areas where erosion had occurred. Since then, the site has shown clear signs of improvement, with reduced erosion and increased vegetation growth helping the mire recover.
Fixed Point and Timelapse Photography
Forestry England has developed a comprehensive fixed point photography programme to help monitor its wetland restoration sites. Photos are taken before and after restoration work and used to assess the impact of restoration work on the form and functioning of the streams and wetlands. These help measure the outcomes of the restoration against the criteria developed by the Freshwater and Wetland Restoration Forum. See the Furzey Lodge and Hawkhill case study for an example of how fixed point photography is used for monitoring.
Case studies
The fixed-point photography at Furzey Lodge and Hawkhill indicates the outcomes of the restoration were achieved.
- The straightened channel at Furzey Lodge, running through the lawn habitat south of Rans Wood, has been restored to a more natural, winding, and shallow form (Images A–C). Previously, water remained trapped within the deep, straight channel during high flows. The post‑restoration photos show that the new, shallower channel now allows water to spill naturally onto the floodplain during high flows, slowing it down and reducing erosion.
- At Hawkhill, the culverts were concentrating water flow, creating a deep erosion point downstream and causing the channel to erode back toward the mire, which was being unintentionally drained (Images D and E). Following restoration, the repaired channel and new ford crossing allow water to spread more evenly across the area, slowing the flow and reducing erosion. This will help protect the mire upstream.
Continued monitoring of these restoration sites will take place to ensure the restoration work holds as expected.
Other monitoring work
Water quality
Water quality is an important consideration at all restoration sites.
Forestry England monitors key water quality parameters using an Aquaprobe, including pH, dissolved oxygen and electrical conductivity.
Phosphate and nitrate/nitrite levels are also measured at each site to help assess nutrient conditions and detect any potential pollution issues.
Other surveys
Forestry England frequently collaborates with external organisations and specialist consultants to commission survey work that helps measure the impact of restoration projects and guide future management.
For example, the Environment Agency supports FE by deploying water-level monitoring equipment to assess how restoration work influences flood peaks. They also carry out fish surveys, ensuring that any necessary mitigation measures are identified to minimise impacts on fish populations.
FE is also working with Freshwater Habitats Trust on a partnership wetland restoration project. As part of this work, FE has undertaken water-level and eDNA monitoring, alongside vegetation, botanical, geomorphological and fixed-point photography surveys.
In addition, a range of species surveys are commissioned to help inform management decisions.