Current status and trends
The most recent data on Belgium’s biodiversity is available on the website of Statistics Belgium. Before that, a comprehensive survey of Belgium's biodiversity was carried out through questionnaires sent to more than 400 Belgian and international experts between 1998 and 2002.
About 40 500 species of micro-organisms, plants, fungi and animals are known in Belgium.
Slightly more than half of these species are animals. Of these, insects are the most numerous: 4.500 species of beetles, 4.500 species of flies and mosquitoes, 2.400 species of butterflies and moths, etc. Vertebrates are at the bottom of the scale, with only 73 species of mammals and 150 species of fishes.
Plants and fungi amount to about 16.000 species. A more detailed account yields, among others, 1.530 species of vascular plants, 560 mosses, 980 lichens and 60 species of ferns.
In addition to these 40 500 formally inventoried species, biodiversity experts estimate that about 18.000 additional species should be present in Belgium but have not yet been recorded.
This estimation essentially comes from comparisons to the fauna and flora of our neighbouring countries, where records are more extensive. Many species that are found in those countries could well be present in Belgium, since the living conditions that they need are also present in our country.
Detailed monitoring and thorough comparisons of old collection and observation data with more recent ones show that many species are in decline or even have disappeared. It can be estimated roughly that between 20% and 70% of the species are threatened per main group of organism, depending on the group and the region of the country:
• In Flanders, at least 7% of formerly recorded species are extinct. Of the remaining assessed species, 17% are endangered to critically endangered and 29% are vulnerable to near threatened; only 52% are considered safe or at low risk (for 2% of the assessed species, data are insufficient to define a status).
• In Wallonia, 9% of the animal and plant species have already disappeared and 31% of the animal and plant species are threatened to disappear.
• In the Brussels-Capital Region, 80 higher plant species (out of the ca. 580 indigenous ones recorded before 1950), 12 bird species (out of 103) and half of the amphibian species have disappeared.
• The area covered by the Belgian part of the North Sea (BPNS) is part of a larger marine area, affected by sea currents, and as such no clear statement should be made on the state of the population size of species in the BPNS. An increase of invasive species has been identified over the years and some of these invasive species are fairly well inventoried (crustaceans, molluscs, ...). The quality of the structure and function of sandbanks and biogenic reefs have been affected by bottom-disturbing activities.