One Ecosystem :
Case Study
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Corresponding author: Catherine Anne Farrell (doctorcatherinefarrell@gmail.com)
Academic editor: Joachim Maes
Received: 05 Mar 2021 | Accepted: 22 Apr 2021 | Published: 28 Apr 2021
© 2021 Catherine Farrell, Lisa Coleman, Mary Kelly-Quinn, Carl Obst, Mark Eigenraam, Daniel Norton, Cathal O'Donoghue, Stephen Kinsella, Orlaith Delargy, Jane Stout
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Farrell CA, Coleman L, Kelly-Quinn M, Obst CG, Eigenraam M, Norton D, O`Donoghue C, Kinsella S, Delargy O, Stout JC (2021) Applying the System of Environmental Economic Accounting-Ecosystem Accounting (SEEA-EA) framework at catchment scale to develop ecosystem extent and condition accounts. One Ecosystem 6: e65582. https://doi.org/10.3897/oneeco.6.e65582
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Ecosystem accounting is a tool to integrate nature into decision-making in a more structured way. Applying the use of nationally available datasets at catchment scale and following the System of Environmental Economic Accounting-Ecosystem Accounting (SEEA-EA) framework, we present results from a catchment case study in Ireland, highlighting findings specifically in relation to the development of ecosystem extent and condition accounts. In the absence of a national ecosystem map, CORINE landcover mapping formed the basic data for extent and type of ecosystems, distinguishing woodlands and forest, peatland and heathland, grasslands and cropland and urban areas, with limited coverage of linear freshwater rivers, hedgerows and coastal ecosystems. Additional remote sensing data provided higher resolution at catchment scale, while limited site-level survey data were available. Condition data gathered for reporting under the EU Water Framework Directive were available at sub-basin level for surface waterbodies. Data were available at national level for habitats reported for the EU under the Habitats Directive (59 habitats reported), covering ~ 25% of the study area. Data for ecosystem types outside of these reporting frameworks were in the form of ancillary data only, providing information on pressures, threats and intensity of use. Our findings in Ireland reflect work across the European region, highlighting the role of data gathering and stakeholder engagement. We outline some of the data gaps to provide information for future research and alignment of data for the purpose of NCA, both at catchment and national scale.
SEEA-EA, catchment scale, ecosystem stocks, ecosystem extent, ecosystem condition, ecosystem accounts
Repeated calls for the value of nature’s contributions to people to be taken into consideration requires us to bring nature into decision-making at a variety of scales (
Natural systems (such as ecosystems) are complex and therefore require an appropriate accounting model (
With the publication of the European Green Deal in 2019 (EC 2019) and the EU Biodiversity Strategy for 2030 (EC 2020), the call for ecosystem accounting and NCA has been firmly embedded across EU policies. Trialled at different scales (EU region, Member State and provincial scales) and in response to different drivers and policy questions within the European region (
Progress relating to ecosystem accounting in Ireland has been limited, despite being highlighted as a key action in the National Biodiversity Action Plan (
We present findings from a case study piloting the SEEA-EA at catchment scale in Ireland, with a view to providing information for the implementation of the SEEA-EA at varying scales, nationally and internationally. The catchment represents a distinct biophysical landscape unit with well-defined boundaries, forming the basis at which reporting is carried out under the EU Water Framework Directive (WFD). Furthermore, the Integrated Catchment Management approach to preparing River Basin Management Plans throughout the EU, as part of the implementation of the WFD, has many parallels in approach and philosophy with the systems approach of the SEEA-EA (
In this paper, we focus primarily on the ecosystem stocks accounts (extent and condition). The extent account is often the first step in developing a set of ecosystem accounts and presents an entry point to the discussion of ecosystems for a wide range of stakeholders (
The SEEA-EA is a geospatial approach whereby existing data on ecosystem stocks and flows, at a range of scales, are collated. Organising biophysical data in an integrated statistical framework, the SEEA-EA is distinct, but complementary to that of the SEEA-Central Framework (CF), which incorporates the measurement of physical accounts, flows of environmental assets (such as timber, water and minerals) and environmental expenditure (
The SEEA-Ecosystem Accounting Framework. Source: IDEEA Group.
Asset extent: this relates to the type, range and extent of ecosystems assets within an accounting area. Ecosystem assets are the ecological entities for which information is sought and about which statistics are ultimately compiled. The use of national ecosystem typologies, such as the Heritage Council Classification system in Ireland (
Asset condition: this relates to the quality of the assets outlined in the extent account. The SEEA-EA is specific about the definition of ecosystem condition as “the quality of an ecosystem measured in terms of its abiotic and biotic characteristics”. Quality is assessed with respect to ecosystem structure, function and composition, which combine to underpin the ecological integrity of the ecosystem and, thereby, its capacity to supply ecosystem services (
Services: this requires the identification of the flows of ecosystem services, whether within the system or as a product of the system. Services may rely on a combination and the interaction of multiple ecosystem assets. Mapping services can also integrate data relating to pressures and condition mapping in previous steps, as well as using other relevant geospatial data. While data relating to services can be biophysical, there may also be links to economic datasets.
Benefits: this relates to what the benefits and who the beneficiaries are. For some services, there is a spatial correlation between potential beneficiaries and service availability, while for others, the spatial link may be more difficult to ascertain.
Each step of the accounting requires the gathering, assessment and integration of relevant datasets. As a consequence, data review and analysis, combined with iterative engagement with data providers, as well as potential end-users, comprises a major part of the process of developing ecosystem accounts. Following from this iterative, interactive learning process, the accounts provide an integrated data platform that can be used to provide information for decisions, each application depending on the perspective of the end-user(s) (
We built ecosystem extent and condition accounts for a test catchment (the Dargle catchment, located in the Leinster Province of Ireland). The Dargle catchment unit (referred to as the Dargle), is located in the southern suburbs of Dublin City and north County Wicklow in Ireland (Fig.
The Dargle was selected as it is a diverse catchment, comprising eleven river sub-basins and two lake waterbodies. Forming the northern part of the larger Avoca-Varty river system, the Dargle is reported under the EPA WFD code: 10_5 and covers a total area of 17,866 hectares (178 km2). Watercourses in the Dargle drain urban areas to the north; those to the east rise largely in rural uplands characterised by mountain blanket bog and heathlands; and river valley slopes are dominated by coniferous plantations and pockets of remnant native woodland along the riparian nodes. The main stem of the Dargle River drains through the urban centre of Bray into the Irish Sea. The area has a high coverage of habitats listed under Annex I (those habitats whose conservation requires the designation of special areas of conservation) of the EU Habitats Directive (ca. 25% of the catchment area), with a similarly high coverage of Natura 2000 (the network of nature protection areas in the EU) and nationally designated conservation sites.
The national ecosystem typology comprises a comprehensive synthesis of the most frequently encountered ecosystem types in Ireland. The typology is focused on habitats and an overview is presented in Suppl. material
Freshwater: this includes surface water bodies such as rivers, lakes, as well as inland wetlands and swamps.
Woodlands: this category relates to all semi-natural woodland types, including native woodlands, hedgerows, tree-lines and scattered parklands. We distinguished woodlands from commercial plantations (Forest), on the basis of structure and use.
Forest: wooded areas planted and managed for the primary purpose of commercial production.
Peatlands: collectively comprising raised bog, mountain and lowland blanket bog, cutover, fen and degraded peatland types.
Heathlands: wet and dry heathland types (including bracken dominated areas), which often occur in a mosaic with peatlands on peat soils; alpine heathlands occur at high altitudes.
Grasslands: this includes all improved, semi-improved and semi-natural grassland types.
Croplands: areas developed for the purpose of crop production, including cereals, biomass crops, fruit and vegetables.
Coastal: dune complexes, saltmarshes, tidal areas, sea cliffs and beaches are included here; often occurring as linear features.
Urban: this is largely aligned with the national Level 1 ecosystem type Cultivated and built land (Fossitt 2000); the main focus of interest being urban green and blue spaces.
Aligning with and taking into account the structure and resolution of the CORINE datasets, we combined the following ecosystem types (these areas often overlap in CORINE), within our ecosystem accounts and discussions: Woodlands and Forest, Peatlands and Heathlands and Grasslands and Croplands.
Throughout the accounting process, we followed the steps outlined in the SEEA-EA framework as a guide to gather and assess relevant data (
A desktop review of available national and catchment level datasets (with particular focus on the Dargle) was then combined with one-to-one engagement through further focus groups and catchment workshops. Direct engagement across a wide array of agencies, both with data providers and potential end-users of the accounts, identified available relevant inputs and highlighted potential policy applications. The output of this data review and engagement was a data inventory, developed to provide information for both national level and catchment relevant datasets.
Following from the data inventory and development of the ecosystem accounts (see next section), we used these outputs to engage further with national and local stakeholders in the Dargle in autumn 2020. As well as highlighting obvious data gaps and uncovering further supporting ancillary datasets, this iterative engagement provided opportunities to raise awareness as to the approach and gain further input and support from potential end-users.
Applying relevant available datasets identified during the data inventory, we followed the process steps as outlined in the SEEA-EA (
CORINE datasets were analysed using GIS tools (ArcGIS) to develop core extent accounts (maps and tables) for four time series (2000, 2006, 2012 and 2018). While CORINE served as the base layer for the core extent accounts, supplementary datasets (where available and relevant) provided more detail to support and refine detail on the extent of specific ecosystem types. Change in extent accounts were developed for CLC status layers using the EnSym tool.
Condition accounts were developed using available time series data available for the Dargle. This consisted primarily of collating relevant datasets gathered for reporting under the EU WFD. Sample survey data (comprising an assessment of structure and function of sampled habitats) for Annex I habitats in the catchment available under the EU Habitats Directive Article 17 reports were also reviewed, along with survey data for focal areas and ecosystem types within the catchment commissioned as part of other, unrelated studies. These data were supported by available ancillary datasets where relevant. While the SEEA-EA outlines in detail a three-stage approach to develop condition accounts (
Following an iterative process of collating and reviewing data, a data inventory detailing relevant national and catchment related datasets was developed, serving as a technical support document for applying the SEEA-EA in Ireland that can be added to over time. The inventory comprises an extensive array of datasets from national and EU agencies, state departments, local authorities, commercial enterprise, research and ecological consultants. Ancillary datasets, reviewed for the Dargle, include data relating to accessibility (roads and trackways), commercial use (forest plantation data), elevation, planning documents, food production (agricultural payments data), protection status (such as conservation designations) and soils.
The key datasets used for developing extent and condition accounts for the Dargle, as well as most relevant ancillary datasets, are outlined in Table
Key datasets used for developing extent and condition accounts in the Dargle (note: MMU: minimum mapping unit).
Dataset |
Description |
CORINE landcover
Fig. |
Available time series: 2000, 2006, 2012 and 2018. Coverage: National, European Resolution: MMU 25 ha; min. width 100 m for linear features. Relevance: Formed the basis of the core extent accounts. |
Copernicus Land Monitoring Service Data High Resolution Layers (HRLs)
Figs |
Available time series: Variable intervals from 2006, time series not aligned with CORINE. Coverage: National, European. Resolution: MMU variable, ranging from 2-20 m. Relevance: Information on specific land cover characteristics; used to complement, supplement and refine core extent accounts; application described under each ecosystem type. In particular, the Small Woody Features (SWF) HRL and the Urban Atlas and supporting Urban Atlas Street Trees Layer (STL) HRL supplemented data on woodlands and urban green space, respectively. |
EU Habitats Directive Article 17 reporting (Annex 1 Habitats)
Fig. |
Available time series: 2009, 2013 and 2019. Coverage: National. Resolution: Grid square, polygon, polyline and point data available depending on habitat. Extent: Of the 59 EU Habitats Directive habitats reported for Ireland, 24 of these occur in the Dargle, covering ca. 25% of the catchment; habitats comprise mainly Annex I peatland and heathland habitats on uplands, with patches of Annex I woodlands along river valleys and Annex I coastal habitats. Condition: Data on structure and function of Annex I habitats gathered for survey points across a national sampling grid, are aggregated with knowledge on pressures, threats and range, to develop national level Conservation Status and Trends for each habitat. National Conservation Status for the 24 Annex I listed habitats recorded in the Dargle are presented for 2019 (Suppl. material |
Natura 2000 and national designated nature network (ancillary data)
Fig. |
Available time series: Variable. Coverage: Natura 2000 network data relates to SAC and SPAs; for each site a Standard Data Form provides information relating to Annex I habitats and Annex IV species. Boundary data are available for Irish national designations (Natural Heritage Areas, nature reserves and wildfowl reserves) with variable supporting data relating to site information/habitat mapping. Relevance: Up to ca. 24% of the Dargle is covered by designations, overlapping strongly with the area of Article 17 reporting. A desktop habitat mapping study available for one of the larger SAC sites, the Wicklow Mountains SAC, covers ca. 16% of the catchment area. Apart from site code and name (often inferring the dominant habitat type), there are no supplementary data available for national designated sites in the Dargle. |
Soils (Soils Information System) (ancillary data) Fig. |
Coverage: National. Relevance: The soils database delineates the general soil association in an area, as well as providing data on soil texture (peat versus non-peat), soil drainage and soil carbon (indicative ranges). Combined with the Derived Irish Peatland Map (DIPMV.2), developed in 2011 ( |
High Nature Value farming (HNVf) (ancillary data)
Fig. |
Available time series: One-off (2016). Coverage: National. Relevance: Developed using five indicators (semi-natural habitat cover, stocking density, hedgerow density, river and stream density and soil diversity). In the absence of condition data relating to agricultural/enclosed farm areas, this dataset provides a high-level aggregate to identify potential HNVf areas. |
EU Water Framework Directive reporting Fig. |
Available time series: four time series between 2007 and 2018, relating broadly to the WFD cycles. Coverage: National; data are gathered for all waterbodies, including rivers or tributaries, lakes, coastal/transitional waters and groundwater. Resolution: Available to sub-basin level for rivers. Relevance: The main condition indicator for rivers and lakes is ecological status, a pre-aggregated index, based on biotic and abiotic qualitative and quantitative data (supporting physico-chemical and hydromorphological quality elements). Ancillary data: Ecological status is supported by data relating to pressures and threats, as well as characterisation which identifies waterbodies At Risk of achieving or maintaining high or good ecological status. Data are also available on protection status (such as drinking water or salmonid river protected status as in the Dargle shown Fig. |
Catchment related surveys Fig. |
Available time series: variable intervals from 2006. Details: Local surveys available comprise:
These surveys present ecosystem extent data in the national classification scheme. Combined with Article 17 and Natura 2000 datasets, detailed habitat survey data are available for ca. 58% of the Dargle). |
Extent accounts, developed using CORINE data (Table
Ecosystem extent account for the Dargle (based on CLC classes for 2000, 2006, 2012 and 2018 datasets). Area of each CLC Level 3 class is outlined in hectares. We highlight the overall change between 2000 and 2018 in the final column. The total is aggregated to Ecosystem Type level. We note that CLC status layers have been used to assess changes in this Table. We refer to the change account in Table 4. for more detailed analyses.
Ecosystem Type (ET) |
CLC 3 Code |
CLC Level 3 |
2000 |
2006 |
2012 |
2018 |
Total change 2000 to-2018 |
Freshwater |
512 |
Water bodies |
45 |
45 |
26 |
26 |
-19 |
Total |
45 |
45 |
26 |
26 |
-19 |
||
Woodlands & Forest |
311 |
Broad-leaved forest |
166 |
296 |
580 |
580 |
+414 |
312 |
Coniferous forest |
1,421 |
1,886 |
1,788 |
1,830 |
+409 |
|
313 |
Mixed forest |
550 |
477 |
372 |
372 |
-178 |
|
324 |
Transitional woodland-shrub |
1,444 |
850 |
625 |
486 |
-958 |
|
Total |
3,580 |
3,508 |
3,366 |
3,268 |
-313 |
||
Peatlands & Heathlands |
322 |
Moors and heathland |
0 |
2,214 |
3,125 |
3,157 |
+3157 |
333 |
Sparsely vegetated areas |
0 |
73 |
28 |
28 |
+28 |
|
334 |
Burnt areas |
0 |
0 |
0 |
65 |
+65 |
|
412 |
Peat bogs |
4,062 |
1,897 |
1,201 |
1,201 |
-2,861 |
|
Total |
4,062 |
4,184 |
4,354 |
4,451 |
+389 |
||
Grasslands & Croplands |
211 |
Non-irrigated arable land |
706 |
442 |
444 |
476 |
-230 |
231 |
Pastures |
3,575 |
3,095 |
3,132 |
3,056 |
-519 |
|
242 |
Complex cultivation patterns |
934 |
587 |
527 |
487 |
-447 |
|
243 |
Land principally occupied by agriculture, with significant areas of natural vegetation |
1,259 |
1,607 |
1,732 |
1,756 |
+497 |
|
321 |
Natural grassland |
140 |
0 |
0 |
0 |
-140 |
|
Total |
6,614 |
5,731 |
5,834 |
5,775 |
-839 |
||
Coastal |
523 |
Sea and ocean |
9 |
9 |
10 |
10 |
+1 |
Total |
9 |
9 |
10 |
10 |
+1 |
||
Urban |
111 |
Continuous urban fabric |
0 |
37 |
46 |
46 |
+46 |
112 |
Discontinuous urban fabric |
2,441 |
2,645 |
2,629 |
2,636 |
+195 |
|
121 |
Industrial or commercial units |
78 |
119 |
257 |
276 |
+198 |
|
122 |
Road and rail networks and associated land |
85 |
199 |
198 |
198 |
+113 |
|
131 |
Mineral extraction sites |
0 |
0 |
26 |
0 |
0 |
|
132 |
Dump sites |
30 |
81 |
0 |
0 |
-30 |
|
133 |
Construction sites |
66 |
158 |
31 |
90 |
+24 |
|
141 |
Green urban areas |
191 |
151 |
93 |
93 |
-98 |
|
142 |
Sport and leisure facilities |
485 |
818 |
817 |
819 |
+334 |
|
Total |
3,375 |
4,208 |
4,097 |
4,157 |
+782 |
In terms of general trends, the data show that, between 2000 and 2018, there were overall declines in cover of freshwater, woodlands and forest, grasslands and croplands, while peatlands and heathlands and urban areas in the Dargle have increased (Table
Ecosystem extent expressed as % cover of the total Dargle area for 2000, 2006, 2012 and 2018 (total area of the Dargle is 17,866 ha).
Ecosystem Type (ET) |
2000 |
2006 |
2012 |
2018 |
Freshwater |
0.3 |
0.3 |
0.1 |
0.1 |
Woodlands and Forest |
20.2 |
19.8 |
19.0 |
18.5 |
Peatlands and Heathlands |
23.0 |
23.7 |
24.6 |
25.2 |
Grasslands and Croplands |
37.4 |
32.4 |
33.0 |
32.7 |
Coastal |
0.1 |
0.1 |
0.1 |
0.1 |
Urban |
19.1 |
23.8 |
23.2 |
23.5 |
Dargle catchment change in extent (hectares) account (2000 to 2018) for CLC Landcover Level 3 classes, developed using the EnSym tool (CLC status changes). Note that two CLC3 classes occur in 2000 datasets, but not in 2018 datasets (CLC Dump sites and CLC Natural grassland). Summary changes (hectares) are highlighted in Table
Urban |
Grassland and Cropland |
Woodlands and Forest |
Peatlands and Heathlands |
Freshwater |
Coastal |
||||||||||||||||||
CLC Level 3 |
Continuous urban fabric |
Discontinuous urban fabric |
Industrial or commercial units |
Road and rail networks and associated land |
Dump sites |
Construction sites |
Green urban areas |
Sport and leisure facilities |
Non-irrigated arable land |
Complex cultivation patterns |
Pastures |
Natural grassland |
Land principally occupied by agriculture, with significant areas of natural vegetation |
Coniferous forest |
Mixed forest |
Broad-leaved forest |
Transitional woodland-shrub |
Burnt areas |
Moors and heathland |
Peat bogs |
Sparsely vegetated areas |
Water bodies |
Sea and ocean |
Opening Stock |
2,446 |
79 |
84 |
29 |
66 |
192 |
482 |
706 |
934 |
3,577 |
141 |
1,260 |
1,421 |
551 |
166 |
1,441 |
4,058 |
46 |
9 |
||||
Total additions to stock |
46 |
373 |
196 |
112 |
91 |
1 |
368 |
204 |
168 |
804 |
1,024 |
961 |
165 |
523 |
375 |
64 |
3,155 |
14 |
27 |
1 |
|||
Total reductions in stock |
(178) |
(1) |
(1) |
(29) |
(66) |
(100) |
(32) |
(432) |
(615) |
(1,323) |
(141) |
(528) |
(555) |
(344) |
(106) |
(1,330) |
(2,869) |
(20) |
(0) |
||||
Net change in stock |
46 |
195 |
196 |
111 |
(29) |
25 |
(99) |
336 |
(229) |
(446) |
(520) |
(141) |
497 |
406 |
(180) |
417 |
(955) |
64 |
3,155 |
(2,856) |
27 |
(20) |
1 |
Closing stock |
46 |
2,642 |
275 |
194 |
- |
91 |
94 |
818 |
477 |
488 |
3,058 |
- |
1,756 |
1,827 |
371 |
583 |
485 |
64 |
3,155 |
1,202 |
27 |
25 |
9 |
Additions to stock (%) |
0.0% |
15.2% |
247.3% |
133.5% |
0.0% |
138.4% |
0.5% |
76.5% |
28.8% |
18.0% |
22.5% |
0.0% |
81.3% |
67.6% |
29.9% |
315.5% |
26.0% |
0.0% |
0.0% |
0.3% |
0.0% |
0.0% |
8.8% |
Reductions in stock (%) |
0.0% |
(7.3%) |
(0.6%) |
(0.9%) |
(100.0%) |
(100.0%) |
(51.9%) |
(6.7%) |
(61.3%) |
(65.8%) |
(37.0%) |
(100.0%) |
(41.9%) |
(39.1%) |
(62.5%) |
(64.1%) |
(92.3%) |
0.0% |
0.0% |
(70.7%) |
0.0% |
-44.5% |
-2.9% |
Net change in stock (%) |
0.0% |
(8.0%) |
(246.7%) |
(132.6%) |
100.0% |
-38.4% |
51.4% |
(69.8%) |
32.4% |
47.8% |
14.5% |
100.0% |
(39.4%) |
(28.6%) |
32.6% |
(251.4%) |
66.3% |
0.0% |
0.0% |
70.4% |
0.0% |
44.5% |
-5.9% |
Aggregated change in extent account (hectares) and % of catchment area for CLC Level 3 classes aggregated to Urban (Ur), Grassland and Cropland (G/C), Woodlands and Forest (W/F), Peatlands and Heathlands (P/H). Freshwater (FW) and Coastal (C). Numbers reported in brackets indicate a reduction.
CLC Level 2 |
Ur |
G/C |
W/F |
P/H |
FW |
C |
Total Ha |
Total ha Change 2000-2018 |
781 |
(839) |
(312) |
391 |
(20) |
1 |
0 |
Total % Change 2000-2018 |
4 |
(5) |
(2) |
2 |
(0) |
0 |
0 |
Total landcover category |
4,158 |
5,778 |
3,266 |
4,448 |
25 |
9 |
17,684 |
Percentage of catchment |
24 |
33 |
18 |
25 |
<1 |
<1 |
Detailed ecosystem extent accounts for the Dargle reveal which land classes (and high-level ecosystem types) have changed over the accounting period (Suppl. material
Freshwater: This ecosystem type includes the CLC Level 3 class Waterbodies (< 1% cover of the catchment). CORINE records the extent of one of two lakes in the Dargle, showing a relatively small change over the accounting periods. CORINE does not detect rivers, lakes and/or freshwater wetlands smaller than the minimum mapping unit (MMU); these features were supplemented to the CORINE layer using the EPA rivers dataset (Fig.
Woodlands and Forest: As highlighted above, we distingush between Woodlands (all semi-natural types) and Forest (areas planted and managed for the purpose of commercial production) and we describe both types seperately. We note that the CLC classes coincide with commercially planted Forest in the main.
Forest: This high-level ecosystem type covers ca. 20% of the Dargle in 2000, showing a relative decline in 2018 to ca. 18.5%. The change may be attributed to refinement of CORINE, given that the changes correspond to a relative increase in the area of peat bogs (Suppl. material
Woodlands: There are no woodlands (hedgerows or patches of semi-natural native woodland types) detected by CORINE, despite an extensive network of hedgerows, parkland and riparian woodland areas obvious from aerial imagery. Overlaying the CORINE dataset with commercial forest datasets, the SWF and STL HRLs and catchment survey data, increased the total extent of woodlands and forest cover (taking overlaps into consideration) from ca. 18.5% to 40%. In particular, the SWF and STL HRLs highlighted the network of hedgerows and additional woody features undetected by CORINE (Figs
Peatlands and Heathlands: In 2000, only Peat Bogs were detected by CORINE, while the data distinguished four CLC Level 3 classes in 2018, namely Peat Bogs, Moors and Heathlands, Sparsely vegetated areas (screes on mountain slopes) and Burnt areas. This is attributed to an improvement in the distinction between these closely-related systems by CORINE after 2000. In total, these ecosystems accounted for 23% of the catchment in 2000, with a marginal increase to 25% in 2018. Overlaying Article 17 habitat mapping (Fig.
Grasslands and Cropland: Grasslands and Cropland cover ca. 33% of the catchment in 2018, showing an overall 5% decline in cover from 2000. The CLC Level 3 class Pastures is most extensive for all accounting periods, declining by ca. 500 ha between 2000 and 2018. CLC class Complex cultivation patterns shows a similar decline. For both of these classes, the area was converted to a range of CLC classes, including other grassland types, urban fabric, as well as golf courses (verified by aerial imagery). The area of the CLC Level 3 class Lands principally occupied by agriculture with significant areas of natural vegetation, showed an overall increasing trend for the same time period. Croplands (CLC Non-irrigated arable land) cover a relatively low area (< 3%) of the catchment, also showing a decline. Applying the HNVf layer shows that outside of urban areas, the Dargle lies in the High potential HNVf category (Fig.
Coastal: Accounting for less than 1% of the Dargle, the CLC classes, detected in this category (Sea and Ocean), align with coastal margins. These data were supplemented with Article 17 datasets for Annex I coastal habitats and show that this area includes a relatively small sand dune complex, a fringe of tidal mudflats along the eastern boundary and a section of sea cliffs south of Bray.
Urban: Urban fabric in the Dargle is extensive in 2018 (ca. 23.5% of the catchment) increasing by ca. 4.5% between 2000 and 2018 across the urban CLC classes. The greatest increase was between 2000 and 2006, corresponding to a period of intense economic growth and expansion of infrastructural developments in Ireland. Focusing on green spaces, between 2000 and 2018, Green Urban areas showed a gradual decline to 93 ha (reduced by over half), while Sports and leisure facilities double in extent to over 800 ha (comprising golf courses mainly). Supplementing these data with the Urban Atlas HRL increased the extent of Urban green space from a few scattered patches (< 0.5% using CORINE) to ca. 3% of the catchment. Applying the Urban Atlas STL HRL also highlighted that urban areas in the catchment have a significant network of wooded areas, not detected by CORINE.
Freshwater: Condition account data, available for rivers and lakes in the Dargle to sub-basin level, are shown in Table
Ecological status of freshwater rivers and lakes and WFD reporting in the Dargle (WFD Cycle 2 Sub-catchment Dargle_SC_010) (Note: SP refers to Significant pressures).
Waterbody Name |
Type |
2007-09 Baseline |
2010-12 Mid-term review |
First Full Cycle reporting period 2010-15 |
Assessment to 2018: 2013-18 |
WFD Risk Status 2010-2015 |
Protected area |
SP |
Bray lower |
Lake |
Good |
Moderate |
Good |
Good |
Not at risk |
||
Bray upper |
Lake |
Unassigned |
Unassigned |
Unassigned |
Unassigned |
Not at risk |
||
Carrickmines Stream_010 |
River |
Moderate |
Moderate |
Moderate |
Moderate |
At risk |
Y |
|
Kill of the Grange Stream_010 |
River |
Poor |
Poor |
Poor |
Poor |
At risk |
Y |
|
Shanganagh_010 |
River |
Moderate |
Good |
Good |
Moderate |
Not at risk |
Drinking Water |
Y |
Glencullen_010 |
River |
Good |
High |
Good |
High |
At risk |
Drinking Water |
Y |
Glencullen_020 |
River |
Good |
Good |
Good |
Good |
Not at risk |
||
Dargle_010 |
River |
High |
Good |
Good |
Good |
At risk |
Salmonid |
Y |
Dargle_020 |
River |
Good |
Good |
Good |
Good |
Not at risk |
Salmonid |
|
Dargle_030 |
River |
Moderate |
Good |
Poor |
Moderate |
At risk |
Salmonid |
Y |
Dargle_040 |
River |
Unassigned |
Unassigned |
Good |
Good |
Not at risk |
Salmonid |
|
Glencree_010 |
River |
Moderate |
Good |
Good |
Good |
Not at risk |
||
Kilmacanoge_010 |
River |
Moderate |
Moderate |
Moderate |
Moderate |
At risk |
Y |
Ecological status in 2018 ranged from poor, for the urban dominated sub-basin of the Kill of the Grange Stream, to high for the largely rural, forest dominated Glencullen_010 sub-basin. While forest cover is not increasing in the catchment (based on the extent accounts), other management practices, such as clear-fell and replanting, are ongoing. Between 2012 and 2015, ca. 50 ha of mature conifer forest was clearfelled and subsequently replanted (based on commercial data and analyses of aerial imagery. Despite the notable difference in ecological status, both watercourses are considered At Risk (2010-2015 assessment period) of maintaining or achieving high ecological status due the significant pressures (urban and forestry, respectively), identified in each sub-basin (Fig.
The Kill of the Grange Stream show consistently poor ecological status. Four other watercourses show moderate ecological status; these sub-basins are also characterised by urban dominated land cover. These include the Carrickmines Stream, Shanganagh and Kilmacanogue Rivers and the Dargle_030, each of which are below good ecological status. The Dargle River is a salmonid river and, despite being in good ecological status in the main (apart from the Dargle_030), two of four sections are considered At Risk (hydromorphological pressures in the upper reaches and urban pressures in the lower sub-basins).
Overall, significant pressures in the Dargle relate largely to urban wastewater and diffuse urban water run-off; forestry is a significant pressure in the Glencullen_010 and hydromorphological changes is a pressure in the Dargle_030. Neither of the lakes in the uplands is considered At Risk.
EU Habitats Directive datasets: Survey data available for Article 17 sampling points within the Dargle show that locally, fragments of Annex I listed woodlands, such as Residual Alluvial Forests, are in Favourable Conservation status, though at national level, they are reported as Bad. These differences relate to the sample point data and highlight that catchment level status assessments do not reflect the national assessment. Survey points in the catchment for Old Oak Woodlands, Sand Dune complexes, Sea cliffs and one farm level survey sites with Annex I heathlands show these Annex I habitats as being of Unfavourable Conservation status. Again, at national level, these habitats are assessed as being Bad. These survey data comprise one sample plot for each habitat type, surveyed at variable intervals. While there are survey data for a limited number of sample plots within the catchment area (Fig.
The ecosystem extent accounts developed in this study show that there have been subtle changes in the cover of ecosystem types in the Dargle over the accounting period (2000 to 2018). The main changes detected are the conversion of agricultural land cover classes to urban fabric, during a period of intense economic growth around Dublin, reflecting a similar trend across the EU Region (
Relatively small changes in ecosystem composition, however, can result in wider effects across ecosystem stocks and flows. While freshwater river ecosystems comprise a relatively low cover of the study catchment, their condition serves as an effective indicator of wider land use and land use change and the general environmental quality in a given catchment or sub-basin, as shown in the Dargle. Data gathered under the WFD allows for reliable, time-series condition reporting, while also taking into consideration pressures and trends to provide information for targeted measures to improve water quality and reduce pressures according to Integrated Catchment Management principles. Applying the SEEA-EA at catchment (or sub-basin) scale brings added value to and makes effective use of these WFD data, which provide an indicator of the condition (ecological status) of freshwater rivers and, in the absence of relevant data gathered for other ecosystems, also serves as an indicator of the condition or environmental quality of the catchment or sub-basin as a whole. In our work applying the SEEA-EA, we conclude that, despite data gaps and limitations (described in the next section), the development of ecosystem extent and condition accounts at catchment scale is both feasible and effective in building a narrative around the changing composition of ecosystem types over time, particularly from the perspective of management of water resources. This is also being explored across the EU region (
Each step of ecosystem accounting requires the integration of relevant datasets and consequently the detail provided by each account is reliant on the available data inputs. We discuss the limitations of and relevant data gaps uncovered, offering some conclusions to facilitate and streamline the use of the SEEA-EA at catchment and other scales.
In the absence of a detailed ecosystem map and/or other higher resolution data, CORINE datasets provided the necessary contiguous, time-series data to support the development of indicative ecosystem extent accounts at catchment scale. This reflects the use of CORINE for high-level ecosystem and landcover reporting across the EU Region at Tier I (EU Region, using CLC Level 2 classes) and Tier II levels (national regions, using CLC Level 3 classes) (
Distinction of ecosystem types: In this study, we broadly aligned CLC Level 3 classes to Level 1 of the national ecosystem typology (
Detection of linear features: rivers, hedgerows and landscape features less than the MMU or minimum mapping width of CORINE (such as locally-important wetlands and woodlands) were not included in the CORINE, based core extent accounts for the Dargle. Supplementary datasets are effective in refining and providing detail but, in general, these are gathered at varying intervals and scales and are generally not consistent either with each other or the available CORINE time series.
These limitations extend across all scales of reporting, however, presenting recurring challenges in building ecosystem accounts at any level, as shown across the EU Region (
Further alignment with the IUCN Global Ecosystem Typology (
Condition accounts are the least developed within the European Region and at national levels, though efforts are becoming more focused (
In relation to our case study, WFD data provides a comprehensive resource to develop ecosystem condition accounts for waterbodies in general and, by extension, as highlighted already, this can be extended to the related sub-basins in the absence of condition data for other ecosystem types. Ecological status is a pre-aggregated index which may be used as a sub-index as part of Stage 3 of condition accounting and has been used in ecosystem accounting in European case studies (
Aligning ancillary datasets with the core extent accounts data in the Dargle illustrated the effective use of soils data to infer the historical extent of peatlands and heathlands. This is an important consideration for the use of cultivated peat soils and the resultant contribution to climate regulation. In this way, ancillary data and proxies can be used to effect, serving as placeholders to highlight data gaps until more appropriate data are gathered (
The challenges identified in this case study reflect those identified in other studies and include the lack of data to build condition accounts, the absence of targeted and reliable time-series data on structure and function, as well as the need for agreed reference levels (
In relation to peatlands, data relating to drainage and vegetation cover, is often reflected in the name of the peatland ecosystem type (Level 3 of the national ecosystem typology). Within the Dargle, a desktop survey of the Wicklow Mountains SAC highlights areas of active blanket bog (considered to be good condition), as well as cutover bog and eroding bog (considered to be drained and eroding, therefore inferring poor condition) within the SAC area. Linking these data with remote sensing approaches detecting peatland drainage (
While challenges remain, following the examples of other studies (
Ecosystem accounting and inter alia NCA, is an iterative process requiring a learning curve by all involved. While ecosystem accounting is becoming a focal point of policy instruments (EC 2020), the process takes time to become embedded in ways of thinking and working, requiring a coherent and aligned, adequately resourced approach as shown in countries, such as The Netherlands (
Focusing on ecosystem stocks accounts at catchment scale, we conclude from our work to date that the SEEA-EA accounting framework can be applied and used to effect, particularly to support sustainable use of water resources through the lens of Integrated Catchment Management and the WFD. Aligning and overlaying disparate datasets gathered from an array of agencies was central to building the narrative of ecosystem composition and trends in the Dargle. More detailed datasets, specifically in relation to finer detail of ecosystem types, as well as gathering of data on ecosystem condition variables across all ecosystem types, will support more detailed accounts and, therefore, wider applications at catchment and other scales (
Iterative engagement throughout the work on this case study has provided varied opportunities to raise awareness as to the SEEA-EA approach and potential applications across an array of sectors including agriculture, forestry, marine, nature conservation and spatial planning. While the most obvious application has been in relation to catchment management, there has been a high level of interest from the agricultural sector in terms of guiding initiatives, such as Results Based Agricultural Payments Schemes and proposed Payments for Ecosystem Services Schemes. Further development of the SEEA-EA is ongoing and the establishment of an Ecosystem Accounts unit within the Irish Central Statistics Office in 2020 is a further step towards facilitating integration of the approach into governmental decision-making.
We note that, in terms of ecosystem accounting, the appropriate resolution required for the accounting exercise depends on the scale of the study area and this, in turn, is informed by the purpose or proposed application (the policy question) of the accounting (
This work has been carried out as part of the INCASE (Irish Natural Capital Accounting for Sustainable Environments) project, funded under the EPA Research Programme 2014-2020. The EPA Research Programme is a Government of Ireland initiative funded by the Department of the Environment, Climate and Communications. It is administered by the Environmental Protection Agency, which has the statutory function of co-ordinating and promoting environmental research (www.incaseproject.com).
Trinity College Dublin
The authors have declared that no competing interests exist.
This excel file contains two worksheets. The first outlines the Irish national ecosystem typlogy; the second outlines the alignment of the national typology with CLC Level 3 classes recorded in the Dargle for the development of high level ecosystem types. We also align both with the IUCN Global Ecosystem Typology.