Nature protection and biodiversity - Drivers and pressures (Denmark)

The main pressure on Danish biodiversity are identified to be: Urbanisation, cultivation, pesticides, eutrophication, land drainage, overgrowing, high-intensity logging in forests and plantations, former activities to straighten and dam watercourses and commercial fishing.

Arable land comprise approximately 62 % of the total area in Denmark. Besides producing food crops, these fields are home to many species of plants and animals and thus are highly significant for biodiversity. Arable land has become more homogeneous and many hedges have disappeared. Fields are on average 7 % larger than they were ten years ago.

Although the atmospheric deposition of nitrogen to the terrestrial and the aquatic environment has decreased since 1990 the critical loads for sensitive habitats, i.e. heaths, commons, raised bogs and ‘Lobelia lakes’ (after Lobelia dortmanna), have been exceeded in the monitoring period 1990-2008. Approximately 1/3 of the atmospheric deposition is from foreign sources.

Pesticide treatment has increased since 2000 and the application frequency increased by more than 50 % from 2000 (2.07 times per year) to 2008 (3.16 times per year).

The quality of the Danish forest is poor, measured in the number of old trees, dead wood and undisturbed forest. On average, dead wood in Danish forests amounts to 4.7 m³ per hectare compared to 70 m³ per hectare in natural forests. Natural forest only covers 7 % of the total forest area in Denmark. Six out of nine types of forest have been labelled as having a favourable conservation status in accordance with the EU Habitats Directive for the period 2001-2006.

Marine invasive species are particularly worrying because it is very difficult to control the prevalence of marine species. An estimated 2 656 species in Denmark are not indigenous. Of these, 63 species are invasive and a further 17 species are known as potential invaders, as they appear as invasive species in countries close to Denmark. Examples of invasive species in Denmark are the warty comb jelly (Mnemiopsis Leidyi) and the Pacific oyster (Crassostrea gigas). These species influence the biological balance in Denmark.

Figure 7 (6.1.2): Average field size in hectares (ha) in Danish agriculture. The marked drop between 2004 and 2005 was due to a change in the grant scheme allowing grants for fields as small as 0.3 ha. This resulted in the recording of such fields. Source: Danish National Environmental Research Institute.

Figure 8 (1.2.2): Frequency of pesticide application in Danish agriculture. Because the calculation method changed in 1998 and the target set for frequency of application is based on an old method, both are shown. Reference: Statistics Denmark and The Danish Environment Agency.

Figure 9 (6.7.1): Average nitrogen (N) deposition from the atmosphere on Danish land areas. The figure shows critical loads for some of the most sensitive habitats and deciduous forest. For comparison, an ordinary cereal field is fertilised with approximately 150 kg nitrogen per ha per year Source: Danish National Environmental Research Institute and the Forest and Nature Agency.

Figure10 (6.7.2): Average nitrogen (N) deposition from the atmosphere on Danish sea areas. Source: Danish National Environmental Research Institute.

Figure 11 (6.7.3): Atmospheric nitrogen deposition in kg N per ha in 2008. Based on calculation models. Source: Danish National Environmental Research Institute.

Figure 12 (1.3.1). Development in number and production area in ecological farming. Source: Statistics Denmark and the Danish Plant Directorate.

Figure 13 (6.3.2): Volume of dead wood in Danish forest in 2006, measured in m3 of dead wood per ha of forest. In comparison, a natural forest contains over 70m3 of dead wood per hectare. Source: Forest and Landscape.

Figure 14 (6.8.1): Accumulated figures for introduced species recorded in Danish natural habitats, collated according to the year of the first find. Only a small percentage of introduced species are defined as invasive (see text). Source: NOBANIS.