First National Report of Belgium
to the Convention on Biological Diversity


3. The Brussels Capital Region


by Didier Gosuin, Regional Minister for Environment, Renovation, Culture, Tourism and Welfare

Is an urban environment compatible with wildlife?

In the context of an urban environment, is there any point in even mentioning biodiversity ?

Such questions have been asked more than once. The human-urban habitat is very different indeed from the habitat of wild flora and fauna. Where else than in the urban environment are nature and biodiversity subjected to such continuous and severe pressure ? Any discussion concerning biodiversity in urban environment, particularly on the scale of the Brussels Capital Region, could seem trivial. However, at times where almost half of the world's population lives in urban areas, such a debate becomes inevitable. The Brussels Capital Region has been discussing this subject for some time. It should be highlighted that it is one of the few large cities running an information network on urban flora and fauna, and in which biodiversity plays a central role.

Nevertheless, the debate on urban biodiversity is complicated. It not only consists in preserving and protecting relics of nature in urban areas by strict regulations; it consists in far more than that. It takes that biodiversity into consideration, which develops as a result of the many possibilities of contact and exchange which are typical of, yet unique to, cities. This makes cities suitable for a high level of biodiversity. Such biodiversity, while implying enrichment, can however also result in a threat to native diversity. Needless to say, this type of biodiversity is of a different scale compared to that encountered in unspoilt rain-forests...

It is important to realise that in the context of urban environment, the issue may not be biological diversity itself, but rather the development of a pleasant living environment, a fundamental part of this being the ‘biodiversity' found therein. In this regard, it is essential to make the public aware of the wealth of biodiversity which surrounds them in their own city. This is merely the first step towards recognizing the importance of the biodiversity of unspoilt forests, wetlands, ...

Biodiversity in the urban environment makes sense; recognition of biodiversity on a world scale surely must start at home. Are people even aware of those common swifts flying around our rooftops ?

3.1. Introduction

3.1.1. Administration and competences

The Brussels Capital Region holds a distinct position due to its limited surface area (+/- 160 km2), the very high urbanisation level, the high population density (about 1 million inhabitants), the tight infrastructure network and the intense economic activity that takes place there. The Region has, like the others, extensive competences in the area of the environment.

These activities are carried out by the Brussels Institute for Management of the Environment (BIME)1, which is a para-regional institution that serves as the environmental administration of the Brussels Capital Region. The BIME collects and analyses the environmental data, distributes the information, gives advice and draws up plans of action, defines the strategy to be followed, intervenes in the fieldwork, promotes the environmental awareness etc. Given the complexity of the urban environment, the BIME is forced to collaborate with all sectors and to take a multi-disciplinary approach. Spatial planning and land policy activities are carried out by the Administration for Urban Planning and Zoning2.

3.1.2. Official advisory bodies

A prominent role is played by the Environmental Council3. Here, both the associative societies and the companies, the social partners and the scientific experts give advice on government decisions that have been enacted. For nature conservation matters, this Council consults the Brussels Higher Council for Nature Conservation4.

3.1.3. Associations

The Brussels Capital Region has a number of associations for the environment in general, which are organised in the federatif associations Inter-Environnement Bruxelles (IEB) and Brusselse Raad voor het Leefmilieu (BRAL). A number of smaller associations focus their attention in particular on nature conservation in the Brussels area; they are often very site-specific or species-group specific.

3.2. Ecosystems and species in the Brussels Capital Region:
the particular status of the Region

In light of the particular status of the Brussels Capital Region - a small, highly urbanised island embedded in the Flemish Region - the term ‘biological diversity' and the development of a policy aimed at preserving and increasing biological diversity must be put in a broader perspective here. Yet, contrary to popular belief, the flora and fauna in the urban environment is anything but poor or trivial. The great diversity of biotopes, both relict and newly developed and typically urban ones, the great dynamism, the good contact and exchange possibilities, lead to a typically urban biological diversity that has its own ecosystems and its own species diversity.

3.2.1. Ecosystems

In the Brussels Capital Region, it is not evident to speak of ‘present ecosystems', since these always exist in a relict and disturbed form. Relevant data has not yet been processed in a systematic manner from a regional perspective. Given the urban nature of the Brussels Capital Region, it is more appropriate to talk about the policy in terms of remaining, open green spaces, which play a role in the conservation of that specific urban biological diversity. The open and green spaces

The Region provides anything but a uniform urban landscape picture. One can distinguish 4 zones, which are determined by the presence of water (web subregion), the city and its building (densely urbanised subregion), the forest (forest subregion) and the rural relics (rural subregion) at the periphery.

Despite the high level of urbanisation, it is a very ‘green' Region: the open, green (non built-up) spaces in the region cover a surface area of 8,563 ha , which is the equivalent of 53% of the Region's surface area (see Fig. 3.1.). However, these green spaces are very unevenly distributed, both from a quantity and quality point of view.

Fig. 3.1. Types of green spaces in % of total open and green surface area (8,563 ha) of the Brussels Capital Region (IBGE-BIM). The blue spaces

The presence of water is essential to preserve the diversity. The only major open waterway is the canal. In addition, there are a number of rivers and brook systems, which are included in the city's park systems, as well as the numerous ponds in the forest and parks. Open water covers a surface area of 172 ha (about 1% of the Region's surface area). The areas with a biological value

The majority of the green spaces with presumed ecological importance were studied to ascertain their ‘biological value'. They are mostly situated at the periphery of the Region. The initial approximate survey shows that the areas representing a high to very high biological value make up about 2,540 ha. This means, on a total surface area of green spaces without the purely private gardens, of some 5,770 ha, about 44% comprises a high biological value, which equals about 15% of the Region's surface area (see Fig. 3.2.).

Fig. 3.2. Sites of high biological value (IBGE-BIM).

Note. The majority of these spaces have the ‘green area' status as planning destination. Nevertheless, a number of very important areas have so far been denied this elementary protection: a total of about 10% (247 ha) of the areas with biological value do not have this essential protective destination status. The building pressure on these areas constitutes a real threat.

3.2.2. Species

Reliable overview data about species in the Brussels Capital Region is available for the following groups: higher plants, mosses, avifauna, herpetofauna, mammals. Since 1990, these data are collected in a co-ordinated fashion in the context of the establishment of a bio-indicator-information-network, based on a collaboration between volunteers and professionals (see also 3.5.4.).

Due to the island position of the Brussels Capital Region in the Flemish Region, with which it forms a biogeographic entity, the interpretation of flora and fauna data may not be useful from a scientific perspective. It is however useful from a political perspective. Indeed, the main green spaces run across region borders (e.g. Forest of Soignes), and a number of species groups are dependent on the ecosystems that are present in the surrounding area (e.g. avifauna).

The interpretation of criteria such as rarity, vulnerability, threatened status... is thus a very complex matter and must be adapted to the specific context of the urban environment, on a Brussels scale. The urban environment is also by nature the privileged immigration place of species, which moreover gives rise to typical urban biodiversity (e.g. bats, fox). However, in recent years, it has appeared that precisely a number of these phenomena have negative consequences on indigenous species diversity: the threat of exotic species, which get optimum opportunities in the disturbed, contact-rich urban environment (e.g. exotic birds, as collar parakeet, Egyptian goose; Californian water turtles; plants as Japanese Knotweed, Big Hogweed; ...).

Table 3.1. Situation of some important groups in the Brussels Capital Region.

Total number

of species









Mammals 46 (?) 44 (?) ? ? ?
Birds 92 85 9 16 24
Higher plants 723 568 65 62 ?
Mosses 223 / 49 67 ?


3.3. Activities and threats

As a result of the predominantly urban nature of the Brussels Capital Region and its social-economic context, the threats to the biodiversity are very intense due to the concentration of the population and the high building degree, which translates into a high concentration of threatening activities and a high recreation pressure.

3.3.1. The high population density

The Brussels Capital Region presently has about 950,000 inhabitants. This means an average regional density of 59.2 inhabitants/ha, who are however unevenly distributed. In addition, there is also a real pressure from the commuters, whose number is estimated at least at 250,000 per day.

3.3.2. Occupation of the space

About half (47%) of the Region's surface area (16,138 ha) is built-up. Of this 2,485 ha, equaling 15%, is taken up by traffic infrastructure (2,000 km of canal, roads, railways). Car parks and infrastructure for public transport increase this proportion to 21%. The remainder is taken up by buildings of all kinds: residential, industrial, commercial, for public services, thus totaling 26% of the region's total surface area. Although there is still non built-up land that is being converted into built-up land (1990-95; + 2.7% built-up land, +1.2% traffic infrastructure), this trend is slower than in the 1980s (+ 9 and 11.6%, respectively). Indeed, there is ever less ‘open' space available.

3.3.3. Threatening activities Atmospheric pollution

Traffic and domestic heating have replaced industry as the main source of atmospheric pollution. More than 90% of air pollution is due to energy consumption. The remaining 10% is attributed to certain industrial production procedures. It concerns in particular SO2, NOx, Ozone, CO, heavy metals such as lead, volatile organic substances, dust, black smoke as a result of diesel use,... Water pollution

Water pollution constitutes a main problem in the Brussels area; water treatment installations are just now under construction. The waterways still used for discharge of waste water are therefore of very poor water quality. A number of surface waters nevertheless show excellent water quality. Soil pollution

The soil pollution is mainly of historic origin: old industrial sites, often also old dumps. Noise nuisance

The sources of sound nuisance are mostly situated in transport (the most important source), industrial activities, construction sites, neighbourhood noise. Water catchment

The extraction of natural resources, such as the extraction of sand limestone and sand in the past, is presently restricted to a limited extraction (4% of needs) of groundwater. The effect of the water catchment on the forest ecosystem is not apparent, although it has never really been examined.

3.3.4. The high recreation pressure

A typically urban threat to biodiversity is the growing and changing recreation need of the inhabitants. The population pressure on the remaining open space is high: about 950,000 inhabitants basically rely on 8,563 ha of green space, of which almost half (4,718 ha) is public, although not always accessible. Recreation pressure is a real threat to the biological diversity of the area. In particular, it causes severe degradations reaching alarming levels in larger green areas, on the periphery of the Region, especially the forests.

The urban context can also induce, as a result of a recreation need, an unexpected threat to semi-natural areas:
- the ‘park transformation' of semi-natural areas
- the taking up of such areas for the creation of private vegetable gardens.

3.4. Objectives

What does the Brussels Capital Region want to do with its biological diversity?

What with the Convention on Biological Diversity?

The guidelines ‘for the development of biological heritage' are incorporated in the Plan of Regional Development (PRD-GEWOP)5, the policy plan of the Brussels Government, of which the finalising was announced in the first Brussels policy declaration (18 October 1989). The PRD-GEWOP pursues a durable management of the urban development, for the protection and improvement of an attractive living area for the population.

This positive attitude is clearly included in the Government declaration of 18 June 1995. In relation to the management of Green Spaces (including Nature conservation) priority is given to:

  • the development of the ‘green network' concept, adapted to the Brussels entity, and this in accordance with the cornerstones of the PRD;
  • the protection of (statutory) green spaces from building pressure;
  • the upgrading of waterways through the green spaces;
  • the making available of the necessary resources to implement the forest decree (which regulates traffic and recreation in the forest);
  • the reinforcement of the protection of the ecological resources in the urban environment.

It clearly reveals two axes:

  • on the one hand, it is obvious that the emphasis is not limited to the protection of the existing green spaces, both through their explicit management and by controlling the recreation pressure on them, but includes the further development of a ‘green network'. While given the urban context the concern is first and foremost social, these objectives are crucial in reinforcing the urban green web as a carrier of biological diversity;
  • on the other hand, there is the explicit willingness to reinforce the ecological resources.

These two objectives lay a solid foundation allowing the development of an urban biodiversity policy. In this respect, it is particularly important to realise that, in view of the entire urban context, ‘biological diversity' in itself may not be the most important thing, but rather the development of a pleasant environment to live in, a pleasant living area, that is determined in part by the development of ‘biodiversity'in the surrounding environment. In this regard it is essential to raise the public's awareness of this biodiversity ‘on the doorstep', also in their own urban environment.

3.5. Strategies and management

It must be stressed that the Brussels Capital Region so far has not developed a specific ‘biological diversity plan'. Indeed, in its view, the conservation and the further development of its own typical urban biological diversity is part of its policy aimed at green spaces. Therefore, there is no specific biological diversity budget. This policy has various aspects: planning, active management, adaptation of the instruments, monitoring and study, information.

3.5.1. Planning

The working out of a high-quality and durable policy relating to green spaces in the urban environment, which also pursues the development of biodiversity, is not feasible without a concrete collaboration between the various sectors concerned. The principal collaboration exists:

  • between the various regional administrations;
  • between regional, municipal and federal administrations;
  • between administrations and non-governmental organisations;
  • between administrations and other public institutions (e.g. railway service...). Creation of the green network

The concept emphasises the cohesion and the continuity of the green spaces in the urban environment. The intention is to integrate the numerous functions of green spaces in the city, the aesthetic, recreative, urban development as well as the ecological ones. As far as the development of the ecological function is concerned, a great deal of attention is paid to the increase of biological diversity. The accomplishment of this green network amounts to the creation of a strategy in different stages:

  1. the creation of planning instruments: the detailed inventory of all open and green spaces (specifically allocated budget for 1996-97: 6 million BEF);
  2. the analysis of this database: this stage is currently being worked out (specifically allocated budget for 1997-98: 6 million BEF);
  3. the proposing of solutions via adequate field actions (budget to be integrated in the budget for development and management of green spaces as from 1998-99). Creation of the blue network

Simultaneously with the creation of the green network, the Region has also taken the initiative of developing the ‘blue network'. The purpose is an integrated, durable and ecologically justified management of the smaller open waterways in the Region. This is a highly interdisciplinary project requiring active co-operation between the various sectors, in particular between the managers of the green spaces and the services of ‘public works'. At present, the preparatory phase is underway (identification of ecological problems). Integration of the concept of the blue and green network in the drawing up of new urban development and sectoral environment plans

The concept of the green and blue network is only useful within a legal framework. A crucial element in the strategy is that the concept and its proposals should be integrated in the urban development plans, presently being drawn up in the Brussels Capital Region.

In particular the Regional Soil Destination plan (PRAS-GBP)6 and the Municipal Development Plans (PCD-GOP)7 will form the foundation of the legal framework for spatial planning of the Brussels Capital Region in the next few decades.

3.5.2. Management Adapted ecological management in the urban green spaces for the promotion of biological diversity

The concept of ‘ecological park' or ‘semi-natural park' adopted a few years ago in the Brussels Capital Region is a fairly new approach for the urban environment in the laying out of green spaces. In this concept, the starting point for (re)-development is the conservation of the original landscape and vegetation and its optimum development.

The Brussels Capital Region has a number of scenic landscape parks with a high ecological value. The ecological management is here as well implemented and/or further expanded for the promotion of biological diversity, both for flora and fauna, for the conservation and/or development of semi-natural grassland, shrubs and ponds.

The Brussels Capital Region has also a substantial surface area of public forest (1,735 ha, of which the Forest of Soignes alone covers 1,642 ha). It concerns mostly ancient forest that was planted with beech in the 18th century, containing relic alluvial alder and ash forests in the valleys. The management focuses on the gradual transformation into more natural forests, whereby the development of a maximum biological diversity is essential. The main problem resides in the intense recreation pressure. One attempts to solve these problems through adapted regulations (see below).

In these public park and forest areas, the challenge is especially the integration of differentiated management. The basic strategy is to draw up adapted management plans for each area.

Finally, one must not overlook the substantial share of the private green spaces (gardens and large domains), which constitute privileged areas in the city for the conservation and development of biological diversity. Since 1992, the Brussels Capital Region has supported a project whereby owners of private gardens are given advice about a more natural management of their garden. Adapted flora and fauna management

The undesired invasion of aggressive plant and animal species threatening the indigenous biodiversity requires efficient management and good information towards managers and the population. The express purpose is to combine local and specific interventions into a global plan of action for the control of undesired species. In addition, there are initiatives aimed at preserving and promoting the typically urban (Brussels) biological diversity, whereby the raising of awareness of the urban population is of vital importance.

3.5.3. Urban nature conservation policy

The majority of the nature conservation instruments were inherited from the federal structure. As a result of this, many laws are either outdated and/or not adapted to the urban nature conservation. Within the administration, efforts are being made to adapt these laws to Brussels reality, with regard to the optimum protection of the sites of high biological interest and the indigenous wild flora and fauna. General

The federal ‘Nature Conservation Act' (13 July 1973) was supplemented in 1995 by the ‘Regional Law pertaining to the conservation and protection of the environment' (27 April 1995). Further efforts are being made for a better integration of the aspects of nature conservation as part of the general environmental policy. Species-oriented protection


The ‘Regional Law pertaining to wild fauna and hunting' (29 August 1991) protects all vertebrates, except fish, and bans all hunting. A number of amendments are in the works, most particularly as part of the preservation of biological diversity:

  • proposals for a few specific deviations, for i.e. exotic animal species threatening indigenous fauna and flora;
  • proposal for specific protection of some rare species.


Wild flora is only protected by the federal law ‘pertaining to measures aimed at protecting certain plant species growing in the wild' (16 February 1976), which is not adapted to the urban rare flora and its threats. The amendment is in the works. Sites-oriented protection: purchase of areas and granting of nature reserve status

Under the ‘Nature Conservation Act' (1973) as early as 1989, and subsequently in 1992, a number of biologically valuable areas received the status of nature reserve, providing an optimum management according to biological diversity. It concerns mostly a few forest areas and one diverse relic farming area with forest and marsh.

Of course, the assigning of the status of regional nature reserve requires that it concerns areas which are owned by the Region. In the years 1988-91, some budgetary space was available allowing the purchase of a few strategic areas, subsequently given the status of nature reserve. As huge amounts were involved, this budgetary space is no more available and purchase of areas is currently out of question.

A strategy that can be adopted in this respect is the ‘ordering of areas', on the basis of the ‘Regional Law pertaining to the conservation of immovable patrimony' (4 March 1993). This strategy has already been used on several occasions to protect a number of large threatened semi-natural areas. This status however does not always allow the necessary management.

The initiatives taken recently which will grant the status of nature reserve to a few important areas relate therefore to areas of public property, that are not threatened in a direct way.

Areas which are not the property of the Region qualify for the status of ‘recognised nature reserve'. So far however, due to the high cost price of land, there is not a single application for the recognition of a private area as nature reserve, by virtue of the ‘Regional Law pertaining to the recognition and subsidising of nature reserves' (25 October 1990). A few specific preservation measures

Pesticides ban

The Brussels Capital Region has a ban on the use of pesticides by public institutions on public properties. Only a handful of exceptions are admitted (‘Regional Law pertaining to the use of pesticides', 2 May 1991).

Visiting of the forests

In order to counter the increasing threats by recreational pressure on Brussels forests, regulations were defined, which are reflected in the ‘Regional Law pertaining to the visiting of Forests in the Brussels Capital Region' (30 March 1995). Based on this, ‘special protection zones' can be defined, where access is strictly regulated. The reglementation, however, does not appear stringent enough. Conservation and application of the EEC directives relating to nature conservation

As regards the application of the Bird Directive (97/43), the Regional Law of 29 August 1992, pertaining wild fauna and hunting, protects all wild birds and their environment. This allows an easy follow-up of the guideline, as no bird guideline areas were defined (criteria not satisfied). As regards the application of the Habitat Directive (92/43), in May 1996 a number of areas were suggested to become a part of the Natura 2000 network. Although the Habitat-directive criteria are not adapted to the urban situation, an effort was made to incorporate the key areas in the network; notably the Brussels Forest of Soignes and three complexes of valley and forest zones. In total, it concerns 1,871 ha.

3.5.4. Study & monitoring

Continuity in the research of the biological diversity in the Brussels Region

Since 1991, there has been co-ordinated research in the field of the biological diversity in the Brussels Capital Region, notably in the context of the establishment of a bioindicator-information-network. The principal goal of this research is to achieve concrete recommendations in terms of the urban environment, and to be able to meet the legal obligation of drawing up the two-yearly statement of the environment (‘Regional Law pertaining to the drawing up of a report on the state of the Brussels Environment', 4 June 1992). The idea is to draw up a periodical statement on the condition and the quality of the biological environment. For this, the most representative groups of organisms that can be studied and monitored easily are the following: birds, herpetofauna, mammals, higher plants, fungi. The data of this convention makes it possible to draw important conclusions about the biodiversity, such as:

  • evolution of certain species, status quo, progress, deterioration, ...;
  • evolution of certain sites;
  • disappearance of species, emergence of others;

that allow recommendations to be formulated relating to the management, conservation or protection of biological diversity, either by taking direct action on the species, or via the areas where the species exist. The current monitoring programme is carried out with a very limited annual budget of 3.3 million BEF. At present, there continues to be a shortage of budgetary resources in the environmental sector.

3.5.5. Information and education

A precondition for the success of a policy aimed at promoting biodiversity is good information and education of the population, especially to raise awareness of the presence of biodiversity ‘close at home'. In relation to nature conservation, the Brussels Capital Region spends about 30 million BEF a year on the development of environment-educational programmes, directed at school children and adolescents as well as adults, by granting subsidies to universities, institutes, education centres, nature conservation organisations, etc.

At present, the foundation for intense co-operation with the Royal Belgian Institute of Natural Sciences is being laid as part of an exhibition programme on urban biodiversity (fauna in the city).


Machteld Gryseels
Brussels Institute for Management of the Environment
Gulledelle 100
1200 Brussels


  1. Brussels Institute for Management of the Environment (BIME)
    = Institut Bruxellois pour la Gestion de l'Environnment (IBGE)
    = Brussels Instituut voor Milieubeheer (BIM)
  2. Administration for Urban Planning and Zoning
    = Administration de l'Urbanisme et de l'Aménagement du Territoire
    = Administratie voor Stedebouw en Ruimtelijke Ordening
  3. Environmental Council
    = Conseil de l'Environnement
    = Raad van Leefmilieu
  4. Brussels Higher Council for Nature Conservation
    = Conseil Supérieur Bruxellois pour la Conservation de la Nature
    = Brusselse Hoge Raad voor het Natuurbehoud
  5. Plan of Regional Development
    = Plan Régional de Développement (PRD)
    = Gewestelijk Ontwikkelingsplan (GEWOP)
  6. Regional Soil Destination Plan
    = Plan Regional d'Affectation du sol (PRAS)
    = Gewestelijk Bodembestemmingsplan (GBBP)
  7. Municipal Development Plan
    = Plan Communal de Développement (PCD)
    = Gemeentelijk Ontwikkelingsplan (GEMOP)


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