The Norwegian nature index 2015 indicates that the nature index value for forest has increased since 1990, while we see a declining trend for wetlands and open lowland landscapes.
The goal of the Natural Diversity Act is that the ecosystems and species in Norway are to be conserved. In order to get a picture of the trends in biodiversity, the government has given the Norwegian Environment Agency the responsibility to establish the Norwegian nature index and to present it every five years.
“The Norwegian nature index is the researchers’ best answer to how the biodiversity is affected by human activity. Even though there are low values and declining trends in several ecosystems, the nature in Norway is generally in better condition than in most European countries,” says Ellen Hambro, director general of the Norwegian Environment Agency.
Within the nature index, each ecosystem is given a value between 0 and 1 that shows how affected the biodiversity is by human impact. A value of 1 represents a reference state more or less without human impact, whereas lower values indicate a deviation from undisturbed nature. For semi-natural landscapes the reference state is defined as land areas that are kept in good condition with traditional management regimes such as grazing and mowing.
Management targets, describing where on the scale from 0 to 1 each of the ecosystems should be, have so far not been set. This would be a political matter in which conservation and utilization of natural resources must be weighed up against each other.
In order to calculate the nature index values, expert groups have assessed the state of more than 300 species that should give a representative picture of the trends of biodiversity. These assessments are combined in order to give a complete picture of the state and trends of biodiversity in each of the major ecosystems.
The Norwegian nature index 2015 shows that the state of biodiversity in Norwegian ecosystems in 2014 is significantly different than the reference state. Ecosystems in water have in general higher values than those on land.
“As expected, forests and open lowland landscapes have relatively low values in the nature index. We have extensive agriculture and forestry, and this causes a certain reduction in the state of biological diversity in these ecosystems. Trends over time in these areas will be more interesting to follow, to see whether we are moving in the right direction in terms of conserving the diversity of species,” says director general Hambro.
Since 1990 there has been a decline in the index values for wetland and open lowland landscapes, which is due to both intensification of agriculture and the overgrowing of areas where traditional management has ceased. Over the same period, the index value for forest has slightly increased. More dead wood is particulary contributing to the positive trend in forests, as well as an increase in deer and blueberries.
In the mountains, the state is now slightly poorer than in 1990. This is partly due to the decline in the populations of ptarmigan, willow ptarmigan, rough-legged buzzard, European golden plover and Lapland bunting.
In open waters of the ocean and off the coast, trends have been generally positive during the period 1990-2014. The index value for the coast has declined a little since 2010, which is due to declining seabird populations as well as in the populations of herring and sand eel. On the marine and coastal seabed, conditions have been relatively stable since 1990.
In fresh water, the state have remained almost unchanged since 1990 for Norway as a whole.
By expert assessments of how sensitive important indicators are for various impact factors , we get a picture of what impacts that are most important for the different ecosystems.
In ecosystems on land that show a declining trend, it is the indicators that are sensitive to land use that contribute most to the reduction. For the mountains, climate change is as important as land use/human intervention.
The nature index is presented in the report Norwegian Nature Index 2015. The state and trends of biological diversity. The results and background information are also available online at www.naturindeks.no.
The results are used for international reporting on biodiversity. It also represents updated knowledge for evaluating possible targets for nature conservation.
senior adviser Eirin Bjørkvollphone: 990 04 482