Ecosystem coverage (SEBI 004) - Assessment published May 2010

Indicator definition

Proportional and absolute change in extent and turnover of land cover categories aggregated to relate to main ecosystem types in Europe from 1990 to 2000.

The 13 ecosystem types discussed represent forests, cropland, semi natural vegetation, wetlands, inland water systems, glaciers, permanent snow and urban/constructed/industrial /artificial areas. This indicator is based on photo-interpretation of satellite imagery, and gives a 'wall to wall' picture of the changes and dynamics in Europe with respect to ecosystems. Additional indicators can be used to further highlight trends in extent and state of each of the ecosystem types mentioned above using computations from other data sources. A sub-indicator of change in seagrass coverage of the European Seas can also be used as a proxy for the marine/coastal ecosystems.

Units

Land cover classes area change in ha

% change of land cover classes

Policy context and targets

Context description

This indicator uses photo-interpretation of satellite imagery to give a rough picture of the trend in area and proportion of the major ecosystems in Europe since 1990.
Satellite imagery offers the potential to characterise land cover over very large areas efficiently and very cost effectively. It is possible to produce land cover maps from satellite imagery based on the spectral properties of each pixel within a scene. By grouping pixels into classes with similar spectral properties and associating these classes with particular land cover types, it is possible to produce maps which delineate land cover. Land cover change is then used to indicate the trends in the extent of major ecosystems, such as forests, croplands, wetlands, etc. For this indicator we use data from the Corine land cover database (CooRdinate Information on the Environment - Corine.

At present, data are available from 23 countries providing Corine land cover (CLC) data in 1990 and 2000 and changes between 1990 and 2000. The CLC data are based on 44 land cover classes that are aggregated into 13 ecosystem types for the purpose of this indicator (see Annex 1). Spectral properties allow the CLC project to distinguish between land cover classes. For example, CLC has three classes showing forest land cover: broad-leaved forest, coniferous forest, and mixed forest. By aggregating the information of these three land cover classes we have information on the extent of the forest ecosystem within the limitations of the CLC data (see section on main disadvantages). The CLC data however are the best available at present to cover large areas of Europe in a harmonised way.

Relation of the indicator to the focal area

This indicator is highly relevant for the CBD focal area on 'Status and trends of the components of biological diversity' as ecosystems are a major component of biological diversity. A particular ecosystem supports a particular set of species and their habitats. If an ecosystem is encroached upon and therefore decreases in area, the species and habitats it supports are at risk and they may not be able to sustain a viable population size. This indicator gives information on the trend in area of several ecosystems at the pan-European level, through the trend in extent of the related land cover. It shows whether the area of an ecosystem has decreased or increased between 1990 and 2000. It can also show if the total area of any ecosystem has remained stable but with a large turnover to and from other categories. Albeit rough, the trends in ecosystem area provide information on the space available for the species and habitats of that particular ecosystem.

Targets

No targets have been specified

Related policy documents

No related policy documents have been specified

Methodology

Methodology for indicator calculation

1. The methodology of data processing is rather simple as the area of a particular ecosystem in 1990 is found by summing up the area of all CLC classes belonging to that ecosystem type. Changes have also been assessed exploring particular land cover changes from one land cover type to another. For more details on Corine methodology and production of the land cover map, see Corine land cover manual at http://www.eea.europa.eu/publications/eea_report_2006_11. The 13 ecosystem types discussed represent forests (forest and tall woodland, transitional woodland), cropland (regularly/ recently cultivated and mosaics), semi natural vegetation (heathland/ scrub/ tundra, grassland/ tall forb, sparcely vegetated land) _⁽¹⁾, wetlands (mire/bog/fen, coastal, marine), inland water systems, glaciers/ permanent snow and urban/constructed/industrial/artificial areas.

2. By use of the Land and Ecosystem Account (LEAC) database, analyses are made of the changes between CLC1990 and CLC2000 for 23 countries. The area of a particular CLC class is given in hectares. With reference to the aggregation table annexed to this form, the areas of various CLC classes have been aggregated to a total area for a particular ecosystem.

_{(1) 26 of the 44 Corine land cover classes are considered as natural and semi natural for the purpose of this indicator (see Annex 1 to indicator 'Fragmentation of natural and semi-natural areas').}

Methodology for gap filling

No methodology for gap filling has been specified. Probably this info has been added together with indicator calculation.

Methodology references

• SEBI 2010 Indicator Screening - Historical Development of Forest Area Based on UN Forest Resource Assessments. Van Brusselen, J. and Larsson T.B., 2005.  SEBI 2010 Expert Group 2, EEA, 2005
• European forest types - Categories and types for sustainable forest management reporting and policy. EEA, 2006.  EEA Technical report No 9/2006. European Environment Agency, Copenhagen, Denmark.

Uncertainties

Methodology uncertainty

No uncertainty has been specified

Data sets uncertainty

No uncertainty has been specified

Rationale uncertainty

MAIN DISADVANTAGES OF THE INDICATOR

The use of remote sensing data implies that some degree of detail is lost. The Corine land cover data set is based on a minimal unit of 25 hectares and this implies that smaller areas of certain habitat types and linear features may not be adequately detected. Other data sets (e.g. statistical offices reporting for forests, cropland, grassland area) cannot be combined in this indicator calculation because the different definitions used as well as the different frequencies in updating will produce incomparable trends.

ANALYSIS OF OPTIONS

The CBD indicator selected under this heading is on Trends of forest area based on FAO data. It focuses very much on global forests, including mangroves and tropical forests, and does not give information on other ecosystem types. The present indicator on ecosystem trends is more appropriate for Europe because it gives a more detailed picture of the European ecosystems and it provides a broader picture of all ecosystems, not only forests.
The information from this indicator based on land cover data, can for assessment purposes be complemented by calculations (based on satellite imagery or statistical information) to provide more detailed information on the following ecosystems:

Ecosystem/habitat and Data sets to be used

Forests

UN-ECE/FAO Forest ResourceAssessment (http://timber.unece.org/index.php?id=32) indicator 4.3. 'naturalness' of the MCPFE set(http://www.mcpfe.org/filestore/mcpfe/Publications/pdf/state_of_europes_forests_2007.pdf), and a forest status indicator that is being developed (based on    surrogate measures for  biodiversity, taking into account concepts like quality, functionality and integrity of forest ecosystems).

Cropland

Area of cropland collected by FAO (FAO Production Yearbook, http://faostat.fao.org/faostat/)

Wetlands

Satellite data on wetlands (methodology to be tested) and data from the Ramsar List of Wetlands of International Importance (http://ramsar.wetlands.org/)

Glaciers

Fluctuations of Glaciers (FoG) - series, published by the World glacier monitoring service (http://www.geo.unizh.ch/wgms/fog.html)

Sea-ice

Data set on Sea Ice at the National Snow and Ice Data Center (http://nsidc.org/data/seaice_index/)

Seagrasses

There are no baseline data sets on coverage readily available at the level of the European seas. Relevant information exists in the World Atlas of Seagrasses, which is publicly available and maintained by UNEP/ WCMC, but has gaps with regard to the European coastline(http://www.unep-wcmc.org/marine/seagrassatlas/index.htm). A voluntary data flow on seagrasses is proposed by the EEA to its member countries.