Nature protection and biodiversity - State & Impacts (SOER 2010)

The state of biodiversity in Belgium is described with indicators on species abundance and detailed with figures on the conservation status of species of European interest for the national (where available) as well as the regional levels. Trends are given for some bird indices (e.g. the European common bird index). The state of biodiversity is always closely connected to the quality and availability of habitat, hence the inclusion of several descriptive figures on the progress of their conservation to conclude the section.

Regarding terrestrial biodiversity, a great percentage of reptiles (71 %), amphibians (60 %) and butterflies (60 %) are currently 'critically endangered'¹. For mammals (36 %), birds (25 %), fish (23 %) and vascular plants (29 %), the situation is slightly better. More worrying is the situation for dragonflies and damselflies where 48 % of the species analysed are critically endangered. Terrestrial biodiversity in Belgium is monitored and managed on a regional level. More precise data are therefore given below per region.

Concerning marine environment, there has been a continuous decline in the number of fish species and crustaceans in the Belgian part of the North Sea, primarily as a result of overfishing².

The trend of the marine bird species occurring in the Belgian part of the North Sea and listed in annex I of the EU Birds Directive is as follows: the populations of little tern (Sterna minor) is in decline while the populations of Sandwich tern (Sterna sandvicensis) and common tern (Sterna hirundo) are stable or fluctuating³. Several reports describe the international importance of the Belgian part of the North Sea for marine bird species.

The trend for marine mammals is less clear, although it is certain that most species remain threatened. Article 17 reporting, in application of the Habitats Directive, mentions positive trends for the harbour porpoise (Phocoena phocoena) (primarily due to a shift of the population in the North Sea), the common seal (Phoca vitulina) and the grey seal (Halichoerus grypus)⁴.

In Wallonia, the species conservation status (see Figure 4.1) is poor for roughly 2/5 of the species in the monitored groups (mammals, birds, reptiles, amphibians, fishes, dragonflies, butterflies, ladybirds, beetles, vascular plants and non-vascular cryptogamous plants). Combining all the groups, 31 % of the species which have been studied run the risk of disappearing. Furthermore, nearly 9 % have already disappeared. Among bats, fish, reptiles, butterflies, dragonflies and damselflies (odonata), more than half of species analysed are in an unfavourable situation.

Update data 2009 (French only)

In the Brussels-Capital Region, the species status is highlighted in Figure 5. It should be stressed that considering the limited size of the Brussels Region (161 km²) and its urban character, it is not possible to strictly apply the IUCN’s criteria to determine the conservation status of the various species. Therefore, the data presented below constitute an estimate and should be considered with caution. In particular, the number of species of mammals present in the Brussels Region could actually be higher than 39 because there is doubt concerning the presence of certain species of bats.

About 50 %, 15 % and 100 % respectively of the native and non-extinct species of mammals, birds, and reptiles and amphibians are threatened (endangered or vulnerable). Compared to other taxonomic groups for which historical data are available in the Brussels-Capital Region, butterflies and dragonflies record a particularly important regression.

For plants, 66 species (out of 578 ’native’⁸plants recorded) are identified as being endangered. Actually, this figure is most likely much higher since the conservation status is unspecified for the majority of the plants. The number of ’neophytes’ (plants arrived under human influence) is rising rapidly. It is currently estimated at approximately 215 species. For mosses and lichens, no distinction is made between native and exotic species. Many exotic animal species are also observed, including inter alia three species of mammals and 11 species of birds.

Figure 1 illustrates the species status in the Flemish Region. The conservation status of 3 451 of the species (9 % of the total) occurring in Flanders has currently been documented. Knowledge on the status of Flemish biodiversity is strongly biased toward vertebrates and vascular plants⁵. From the species assessed, 6 % have recently become regionally extinct and 29 % have been listed as 'critically endangered', 'endangered' or 'vulnerable' so-called Red List species. Butterflies are among the most affected with 25 % extinct and 33 % on the Flemish Red List. Empidids (no extinctions and 15 % on the Red List) and Dolichopodids (9 % extinct and 18 % on the Flemish Red List) prove to be the most robust species groups.

Figure 2 illustrates the evolution of the European Common Bird Index from 1990 to 2007-2008 in Flanders. The ‘Common bird index’ is calculated as the trend abundance of forest, farmland and other common birds. The trend is calculated as annual median over species⁶.

The farmland bird indicator dropped sharply between 1990 and 2000-2002. Afterwards, the decline continued, but less pronounced.

Other species-based indicators for Flanders can be consulted on-line (in English) via the following URL: http://indicatoren.milieuinfo.be/indicatorenportal.cgi?lang=en&id_structuur=71.

Common forest birds have increased (e.g. Lesser Spotted Woodpecker Dendrocopos minor, Eurasian Nuthatch, Sitta europaea).

In Wallonia, near one-third of the nesting bird species are threatened. Threatened species are particularly encountered in open, aquatic and agricultural ecosystems. This situation is notably explained by the fact that the area of the heathlands, fens or grasslands is particularly confined. In agricultural areas, few nesting sites and food resources are available throughout the year, without factoring in the specific impact of certain practices (phytosanitary treatments for instance). According to the last inventories, the abundance of the forest common birds would have decreased by 18.5 % between 2005 and 2009. Moreover, the Farmland bird index dropped by 20.5 % between 1990 and 2009.

The conservation status of ‘species of European interest’ (see Figure 3) has been evaluated as part of the reporting requirements for the EU Habitats Directive, under the Article 17 Report (2001-2006). In the Flemish Region, slightly more than a quarter of the species (16 species, 27 %) have a favourable conservation status. For 12 species (20 %) the conservation status is inadequate and for 22 species (37 %) the status is unfavourable (bad). For nine species there was insufficient data to evaluate the status. The status of aquatic species gives the greatest cause for concern, with only one of the ten species being considered as having a favourable status. Water pollution and eutrophication are the main threats reported for most species.

According to the Article 17 Report for the Habitats Directive, the conservation status of ‘species of European interest’ was deemed to be unfavourable for 73 % of the species in the Continental Region. 67 taxa or groups of taxa were studied. Among them, superior plants and butterflies had the largest number of taxons whose conservation status was unfavourable⁷.

Other species-based data for Wallonia can be consulted on-line at the following URL (in French):

Chapitre 12, Rapport analytique 2006-2007 (2007), available at: http://etat.environnement.wallonie.be/download.php?file=uploads/rapports/Rapport_analytique.pdf

 Partie Etat des composantes de l'environnement, chapitre Faune, flore et habitats, Tableau de bord de l'environnement wallon 2010, available at: http://etat.environnement.wallonie.be/index.php?page=le-tableau-de-bord-2010

Common birds are also monitored in Brussels. Thirteen species have been expanding during the period 1992-2008, two of which are exotic species. Eleven species are declining, while nine species are considered as stable.

More information on biodiversity for the Brussels-Capital Region can be found at:
http://documentation.bruxellesenvironnement.be/documents/EE2006FR_volet2_nature_EV.PDF?langtype=2060 (French)

http://documentatie.leefmilieubrussel.be/documents/EE2006NL_volet2_nature_EV.PDF?langtype=2067 (Dutch)

The overall assessment of conservation status as reported within the framework of the Article 17 reporting of the EU Habitats Directive (2001-2006) is the following: 6 % of the Belgian habitats are in ‘favourable’ conservation status; 13 % are in ‘unfavourable inadequate’, 79 % ‘unfavourable bad’ and 2 % are in ‘unknown’ status. Figure 5 shows the assessment of conservation status by habitat category.

Three-quarters of the 37 habitats have an unfavourable (bad) conservation status and 15 % (seven habitats) have an inadequate conservation status. The latter group comprises two peat and marsh habitats, one heathland, two grassland and two woodland habitats. Consequently, only two habitats have a favourable conservation status, these being one saline habitat (Mudflats and sandflats not covered by seawater at low tide) and one coastal dune habitat (Dunes with Sea Buckthorn). All aquatic habitats are of a unfavourable (bad) conservation status. Water and air pollution pose the most serious threats for most habitats⁹.

Overall, for the continental region, only boxwood xerothermic formations were deemed to be in favourable status. Rivers, megaphorbic areas and acidophilous beech forests with Ilex and Taxus were deemed to be in an inadequate status. The other habitats evaluated are in an unfavourable status. As far as forests are concerned, factors lowering the status basically involve the presence of wide diameter-wood and dead wood (insufficient volume and number). No forest habitat in the continental region had a good evaluation as far as the vertical structure was concerned or the presence of natural regeneration. As well as various structural and functioning problems, the poor evaluation of other formations, such as dry heaths, grasslands and screes, comes from the reduced size of their distribution area in relation to the land area required for the good functioning of the habitat and its long term conservation¹⁰.

In the Brussels-Capital Region, the majority of the habitats are in an unfavourable conservation status. Only two habitats, namely the Hydrophilous tall herb fringe communities¹¹ and the alluvial forests with Alnus glutinosa and Fraxinus excelsior¹², have a favourable conservation status. Despite the small regional scale which sometimes limits the quantitative potential for natural habitat development, it is mainly the habitat quality that causes the generally unfavourable conservation status. Therefore, the future emphasis will lie on improving this habitat quality in order to attain a better conservation status for all habitat types¹³.