B6: Natural functions of water and wetland ecosystems
Short Description
This indicator will track changes in the naturalness of ecosystem functioning across water and wetland ecosystems in England, based on a range of attributes indicating levels of artificial modification. Restoring natural functions to these ecosystems is essential for biodiversity recovery and resilience to climate change and contributes to enhancing ecosystem services such as the provision of clean water and flood regulation.
The indicator will cover rivers, headwater streams, lakes, ponds, wetlands, estuaries and coasts, characterising the naturalness of hydrological, physical, chemical, and biological functions. It uses data from a range of sources, aggregated together in a single hierarchical data framework that serves both high-level reporting needs and detailed biodiversity reporting on individual habitat types (such as chalk streams/rivers and oligotrophic lakes).
The data framework for this indicator enables strategic reporting of the condition or quality of water-related habitats, with respect to nature recovery generally and the favourable conservation status of detailed habitat types. It feeds into broader assessment of the extent, quality, and connectivity of habitats under Indicator D1.
Readiness and links to data
An interim indicator is presented here that presents data on a subset of the ecosystems that B6 will ultimately cover. A headline dashboard is provided, completed with data for freshwater ecosystems (rivers, streams, lakes, and ponds), as well as estuaries and coastal habitats that have been added in this year. This year, additional breakdowns of the naturalness components have been added, displaying the percentage of each habitat falling under each naturalness classification within the broad habitat types of Running Waters (i), Standing Waters (ii) and Estuaries and Coasts (iii). Further work is needed to develop naturalness measurements of the wetlands habitats.
Detail on the hierarchical assessment framework servicing this indicator is provided in the B6 information pack on the Discovering priority habitats in England website. This includes a more detailed dashboard of habitat types, further detail on the assessment of the different components reported for rivers, streams, estuaries, coasts, lakes and ponds, and example assessments of some of the detailed habitat types on which the framework will eventually enable reporting.
Work is ongoing to refine the datasets used for rivers, streams, lakes, ponds, estuaries and coasts and to add assessments of wetland habitats. Detailed B6 progress reports are provided on the Discovering priority habitats in England website. The B6 data framework is being packaged up so that it can monitor these habitats over time and provide trend data. The detailed information pack supporting this interim indicator includes information on data sources, attribute definition and data processing.
Notes on indicator
Naturally functioning ecosystems are considered to not be influenced by artificial modifications and have an absence of pressures. This indicator considers the naturalness of hydrological, physical, chemical and biological functions. The extent to which natural function can be restored in any location will depend on a variety of factors including socio-economic constraints.
Data from a large number of individual attributes, from different sources, feed into the headline dashboard presented here. Each attribute has its own issues relating to data availability, spatial coverage and representativeness, and confidence. The B6 information pack on the Discovering priority habitats in England website provides further information on individual attributes. Detailed outputs within the information pack describe data caveats and limitations relating to individual habitat types.
Indicator components
Table B6: Naturalness scores of water and wetland ecosystems in England, 2022
| Broad habitat | Habitat type | Naturalness component | Class | Score |
|---|---|---|---|---|
| Estuaries/coasts | Coastal | Biological | 3.00 | 2.46 |
| Estuaries/coasts | Coastal | Chemical | 2.00 | 1.94 |
| Estuaries/coasts | Coastal | Cross-cutting | 2.00 | 1.67 |
| Estuaries/coasts | Coastal | Hydrological | 2.00 | 2.12 |
| Estuaries/coasts | Coastal | Overall | 2.00 | 2.20 |
| Estuaries/coasts | Coastal | Physical | 3.00 | 2.80 |
| Estuaries/coasts | Estuaries | Biological | 3.00 | 2.59 |
| Estuaries/coasts | Estuaries | Chemical | 2.00 | 2.23 |
| Estuaries/coasts | Estuaries | Cross-cutting | 2.00 | 1.97 |
| Estuaries/coasts | Estuaries | Hydrological | 3.00 | 2.57 |
| Estuaries/coasts | Estuaries | Overall | 2.00 | 2.41 |
| Estuaries/coasts | Estuaries | Physical | 3.00 | 2.72 |
| Running waters | Headwater streams | Biological | 2.00 | 2.15 |
| Running waters | Headwater streams | Chemical | 2.00 | 2.42 |
| Running waters | Headwater streams | Cross-cutting | 4.00 | 3.74 |
| Running waters | Headwater streams | Hydrological | 3.00 | 2.73 |
| Running waters | Headwater streams | Overall | 3.00 | 2.82 |
| Running waters | Headwater streams | Physical | 3.00 | 3.06 |
| Running waters | Large rivers | Biological | 3.00 | 2.69 |
| Running waters | Large rivers | Chemical | 2.00 | 1.74 |
| Running waters | Large rivers | Cross-cutting | - | - |
| Running waters | Large rivers | Hydrological | 3.00 | 2.49 |
| Running waters | Large rivers | Overall | 3.00 | 2.51 |
| Running waters | Large rivers | Physical | 3.00 | 3.11 |
| Standing waters | Lakes | Biological | 4.00 | 4.36 |
| Standing waters | Lakes | Chemical | 2.00 | 2.29 |
| Standing waters | Lakes | Cross-cutting | - | - |
| Standing waters | Lakes | Hydrological | 3.00 | 2.51 |
| Standing waters | Lakes | Overall | 3.00 | 2.99 |
| Standing waters | Lakes | Physical | 3.00 | 2.80 |
| Standing waters | Ponds | Biological | 3.00 | 3.55 |
| Standing waters | Ponds | Chemical | 3.00 | 2.53 |
| Standing waters | Ponds | Cross-cutting | - | - |
| Standing waters | Ponds | Hydrological | - | - |
| Standing waters | Ponds | Overall | 3.00 | 3.00 |
| Standing waters | Ponds | Physical | 3.00 | 2.92 |
| Wetlands | Bogs | Biological | - | - |
| Wetlands | Bogs | Chemical | - | - |
| Wetlands | Bogs | Cross-cutting | - | - |
| Wetlands | Bogs | Hydrological | - | - |
| Wetlands | Bogs | Overall | - | - |
| Wetlands | Bogs | Physical | - | - |
| Wetlands | Fens | Biological | - | - |
| Wetlands | Fens | Chemical | - | - |
| Wetlands | Fens | Cross-cutting | - | - |
| Wetlands | Fens | Hydrological | - | - |
| Wetlands | Fens | Overall | - | - |
| Wetlands | Fens | Physical | - | - |
Image B6: Naturalness scores of water and wetland ecosystems in England, 2022
Trend description for B6
The 6 currently assessed habitat types cover freshwater, and coastal and estuarine ecosystems. From the freshwater habitats; Large Rivers, Headwater Streams, Lakes, and Ponds each have a combined naturalness classification of 3. These classifications are derived from an average combined score of 2.5, 2.8, 2.99 and 3 for each habitat respectively, while Estuaries and Coastal habitats each have an overall classification of 2, which represents an average combined score of 2.4 and 2.2 respectively. The breakdown of these scores into the individual components highlights that each habitat has been subject to a range of artificial modification within each of the various Naturalness Components. While the majority of the habitats that have available data are shown to have a classification of 3 for their Hydrological and Physical components, the other components show greater variation between habitat types. The lowest score (worst in ecological terms) across the habitats is given to the Biological component of Lakes with a score of 4.36 (Class 4). In comparison, the highest score (best in ecological terms) was achieved by the Cross-cutting component of the Coastal habitats with a score of 1.67 (Class 1).
Assessment of change
No assessment of change was undertaken for this indicator as a suitable time series is not yet available in the Outcome Indicator Framework.
Figure B6i: Naturalness scores of large river and headwater stream ecosystems in England, 2022
Table B6i: Naturalness scores of large river and headwater stream ecosystems in England, 2022
| Naturalness component | Habitat type | Class 1 | Class 2 | Class 3 | Class 4 | Class 5 |
|---|---|---|---|---|---|---|
| Biological | Headwater streams | 64.27 | 0.55 | 9.91 | 6.80 | 18.47 |
| Biological | Large rivers | 51.60 | 0.49 | 8.50 | 6.13 | 33.28 |
| Chemical | Headwater streams | 34.96 | 19.72 | 21.11 | 16.30 | 7.90 |
| Chemical | Large rivers | 61.06 | 14.70 | 15.29 | 7.43 | 1.51 |
| Cross-cutting | Headwater streams | 3.77 | 9.83 | 21.68 | 38.48 | 26.25 |
| Cross-cutting | Large rivers | - | - | - | - | - |
| Hydrological | Headwater streams | 35.27 | 12.89 | 14.89 | 17.49 | 19.47 |
| Hydrological | Large rivers | 46.57 | 9.40 | 13.67 | 9.57 | 20.80 |
| Physical | Headwater streams | 21.25 | 16.07 | 18.12 | 24.19 | 20.37 |
| Physical | Large rivers | 20.62 | 14.24 | 18.31 | 26.78 | 20.05 |
Trend description for B6i
In both of the running waters broad habitat types, the Biological and Chemical components were found to have the highest levels of naturalness (least level of modification). For the biological and chemical components respectively, 65% and 55% of headwater streams have achieved classifications of Class 1 or Class 2. While for the Biological and Chemical components of Large Rivers, 52% and 76% of this habitat type respectively have achieved a classification of Class 1 or Class 2. In contrast, the lowest scoring component (worst in terms of naturalness) of either habitat type was the Cross-cutting component of the Headwater streams habitat type, this recorded 86% of Large Rivers at a Class 3 or lower.
Assessment of change
No assessment of change was undertaken for this indicator as a suitable time series is not yet available in the Outcome Indicator Framework.
Figure B6ii: Naturalness scores of lakes and pond ecosystems in England, 2022
Table B6ii: Naturalness scores of lakes and pond ecosystems in England, 2022
| Naturalness component | Habitat type | Class 1 | Class 2 | Class 3 | Class 4 | Class 5 |
|---|---|---|---|---|---|---|
| Biological | Lakes | 0.00 | 7.52 | 8.94 | 23.83 | 59.72 |
| Biological | Ponds | 18.65 | 5.84 | 19.87 | 13.19 | 42.45 |
| Chemical | Lakes | 38.53 | 18.40 | 23.61 | 14.12 | 5.34 |
| Chemical | Ponds | 47.98 | 10.89 | 7.66 | 6.85 | 26.61 |
| Cross-cutting | Ponds | - | - | - | - | - |
| Hydrological | Lakes | 55.83 | 2.96 | 5.75 | 4.85 | 30.62 |
| Hydrological | Ponds | - | - | - | - | - |
| Physical | Lakes | 30.21 | 11.60 | 26.35 | 11.53 | 20.31 |
| Physical | Ponds | 36.64 | 13.74 | 8.40 | 18.32 | 22.90 |
Trend description for B6ii
Across the standing water habitats when broken down, the Chemical and Hydrological components (where available) were found to have the highest levels of naturalness (lowest level of modification). For the Chemical components 57% and 59% of Ponds and Lakes respectively have achieved classifications of Class 1 or Class 2. Similarly, the Hydrological component of the Lakes habitat type has 59% of all lakes measured reaching a Class 1 or Class 2 score. In contrast, the lowest scoring component (worst in terms of naturalness) of either habitat type was the Biological component of the Lakes habitat type, this recorded 92% of lakes at a Class 3 or lower.
Assessment of change
No assessment of change was undertaken for this indicator as a suitable time series is not yet available in the Outcome Indicator Framework.
Figure B6iii: Naturalness scores of coastal and estuarine ecosystems in England, 2022
Table B6iii: Naturalness scores of coastal and estuarine ecosystems in England, 2022
| Naturalness component | Habitat type | Class 1 | Class 2 | Class 3 | Class 4 | Class 5 |
|---|---|---|---|---|---|---|
| Biological | Coastal | 22.58 | 32.79 | 21.32 | 22.76 | 0.54 |
| Biological | Estuaries | 14.18 | 30.76 | 40.42 | 11.50 | 3.13 |
| Chemical | Coastal | 44.40 | 17.50 | 37.52 | 0.58 | 0.00 |
| Chemical | Estuaries | 36.38 | 11.66 | 48.05 | 0.78 | 3.12 |
| Cross-cutting | Coastal | 51.07 | 32.80 | 14.52 | 1.08 | 0.54 |
| Cross-cutting | Estuaries | 47.69 | 21.84 | 20.85 | 5.45 | 4.17 |
| Hydrological | Coastal | 42.28 | 27.73 | 15.31 | 4.62 | 10.06 |
| Hydrological | Estuaries | 28.81 | 21.81 | 25.83 | 10.53 | 13.01 |
| Physical | Coastal | 20.97 | 22.04 | 26.88 | 16.67 | 13.44 |
| Physical | Estuaries | 24.04 | 25.32 | 18.91 | 17.95 | 13.78 |
Trend description for B6iii
Across the Estuarine and Coastal habitats when disaggregated, the Cross-cutting components were found to have the highest levels of naturalness in both habitat types (least level of modification). For the Cross-cutting components 84% and 70% of Coastal and Estuarine habitats respectively have achieved classifications of Class 1 or Class 2. In contrast, the lowest scoring component (worst in terms of naturalness) of either habitat type was the Physical component of the Estuaries habitat type, this recorded 57% of coastal habitats at a Class 3 or lower.
Assessment of change
No assessment of change was undertaken for this indicator as a suitable time series is not yet available in the Outcome Indicator Framework.