Best results for aquatic and mountain ecosystems
Progress in both marine and freshwater ecosystems
The situation in both marine and freshwater ecosystems has improved from 2010 to 1990. With better management of the commercial fish stocks, the state of biodiversity in all the large sea areas has remained stable or improved. The only exception is the Skagerrak, where the Nature Index indicates a decline for pelagic species. This may be related to overfishing and eutrophication.
In freshwater ecosystems, various measures to improve the state of the environment have produced results. There have been considerable improvements in Southern, Eastern and Western Norway since 1990. International agreement to reduce emissions of air pollutants that cause acidification under the Gothenburg Protocol, and liming of rivers and lakes to reduce the impacts of acidification, have played an important part in this.
No significant change for coastal waters
For coastal waters, the Nature Index shows no significant change from 1990 to 2010 for the country as a whole, but there has been a marked improved in Eastern and Southern Norway. This is explained by better treatment of waste water and a reduction in transport of nutrients from southern parts of the North Sea. However, conditions on the seabed along this part of the coastline have worsened.
The state of biodiversity on the seabed along the coast of Nordland is still poor as a result of overgrazing of kelp forests by sea urchins, although this is markedly less serious than in 1990. The reasons for this phenomenon are unclear.
Deterioration in open lowland landscapes
Open lowland landscapes consist mainly of uncultivated areas that were formerly used as hay meadows and livestock pasture. They have the lowest Nature Index value of all the major ecosystems, mainly because of the discontinuation of traditional mowing and grazing.
Forests and mountains
The Nature Index value for forest ecosystems is also relatively low. Like open lowland, forest ecosystems are strongly influenced by human activity.
Mountain and mire/wetland ecosystems have also shown some deterioriation. In the case of mires and wetlands, this is most marked in North Norway, where palsa mires (peat bogs dotted with palsas, which are hummocks with a core of ice) are thawing relatively rapidly. The negative trend for mountain ecosystems is also most marked in North Norway.
Pressures include physical disturbance, pollution and climate change
Open lowland landscapes becoming overgrown
The semi-natural vegetation types that dominate open lowland ecosystems are dependent on traditional management regimes such as grazing, controlled burning of heathland and mowing. When active management or grazing by livestock is discontinued, coastal heaths, grassland and herb-rich meadows become overgrown with shrubs and trees. The Nature Index indicates that even in the remaining areas of semi-natural vegetation types, the state of biodiversity is generally poor.
Forestry reduces Nature Index values for forests
In general, Nature Index values for forest ecosystems are low, and lowest in Central Norway and Hedmark county. Large-scale harvesting of timber has been continuing for hundreds of years, resulting in a much smaller proportion of old-growth forest and far less dead wood than in natural forests, and therefore less biodiversity.
In addition, modern forestry methods produce denser forests, and their species composition differs from that of natural forests. In recent years, the forestry industry has introduced changes in management that are expected to result in higher Nature Index values in some years’ time. For example, owners are being encouraged not to remove old-growth forest or dead wood. Dead wood is a natural component of healthy forest ecosystems; it supports a wide variety of organisms and is therefore important for the level of forest biodiversity.
Low Nature Index values after ditching and draining of mires
Ditching and draining, peat cutting and cultivation have altered large areas of mire since the 1920s. There are wide geographical variations in the state of mire and wetland ecosystems. In addition, certain types of mires are very sensitive to long-range transport of nitrogen, climate change and motor traffic when there is no snow cover. Hydropower projects and the construction of flood defences have had major impacts on floodplains/wetlands.
Some mountain areas under pressure
The state of biodiversity in mountain ecosystems is generally good, but poorer in certain areas in the southern half of the country. They are under pressure from a combination of factors such as inputs of long-range air pollutants, changes in land use (reduction in summer grazing by livestock, more construction of power lines, roads and holiday cabins), and climate change.
The Nature Index provides an overview of ecosystems
Under international agreements, Norway has undertaken to obtain an overview of status and trends for biodiversity in major ecosystems. The Norwegian Nature Index is intended to provide this, and to indicate whether Norway is succeeding in halting the loss of biodiversity.
Compilation of ecosystem data
The Nature Index is the most extensive compilation of information on Norway’s biodiversity to date. It measures the state of biodiversity in Norway’s nine major ecosystems. A set of indicators has been chosen to represent biodiversity in each of these ecosystems. In all, the Nature Index uses more than 300 indicators.
More knowledge needed
Work on the Nature Index has demonstrated that there are still gaps in our knowledge about biodiversity. We have fairly satisfactory information about vertebrates (fish, birds, mammals ), but know much less about fungi, lichens, mosses, flowering plants and invertebrates.
With a better knowledge base, it will be possible to make more reliable assessments of changes in biodiversity and to develop better and more precisely targeted management regimes. Reports on the Nature Index describe gaps in our knowledge and priorities for further work to improve the knowledge base for the public administration. More knowledge will also improve the quality of the next edition of the Nature Index, to be published in 2015.
Scientists most concerned about trends in open lowland ecosystems
To give an idea of where we need to act to halt the loss of biodiversity, all the researchers who provided data for the Nature Index were asked how they expected the values for “their” indicators to change by 2020. The researchers who assessed indicators for open lowland ecosystems were most concerned about current trends, and in their opinion, action is urgently needed to reverse negative trends.