Red List Indicator, 1995-2013

Endangered and non-endangered species

The number of endangered species on the Red List can be regarded as an indicator for the state of biodiversity in the Netherlands. If many species are endangered, nature is not well preserved and vice versa. Between 1950 and 1995, the number of endangered species has risen dramatically and consequently, the number of non-endangered species has declined (see first tab page). More than 1/3 of all species were put on the Red List during this period because they were endangered to some extent.
The number of endangered species has grown marginally between 1995 and 2005, but has in fact declined somewhat after 2005.

RLI length and RLI colour

The so-called "Red List Indicator" (RLI) reflects changes in the number of species on the Red List and the degree to which they are under threat. There are two RLI versions: RLI length and RLI colour. RLI length (see second tab) indicates changes in the number of species on Red Lists by means of indices, reference year (1995 =100). If the Red List becomes longer (more endangered species), relative to the reference year, the value will exceed 100. If the number of endangered species is reduced relative to 1995, the RLI value drops to below 100 - in other words - the lower the value, the better.
Species on the Red List can be classified according to the degree of threat they are exposed to. The RLI colour (see third tab page) also considers shifts between the various RL categories. For this RLI version, too, a lower value (= less "red") is better. On average, more species have shifted to the category "non-endangered" since 1995 than to "more endangered". The changes are only small and dominated by vascular plants, as this is a very comprehensive group.

Groups of species

Taking separate groups of species into consideration, (fourth tab page), we find that improvement is not restricted to vascular plants only. Since 1995, mammals, dragonflies and vascular plants have improved (see index values below 100 in 2013 in the table) and since 2005 breeding birds and reptiles have shown some signs of recovery (compare index values from 2005 and 2013). Butterflies and amphibians show very little or no signs of recovery. For the class of amphibians, this is caused by only one species, the fire salamander. The fire salamander population was decimated as a result of a new fungal infection.
The RLI represents averages. So after 2005, the Red List status of many species has deteriorated, but the Red List status of an even larger number of species has improved; 28 "vulnerable" and "sensitive" species have improved and 28 have deteriorated. Eight species "seriously threatened" of "threatened" in 2005 have deteriorated further, but 32 species have improved. In fact, the most threatened species have improved. In addition, the number of species has grown after 2005, as 7 species returned, but only 2 have disappeared.

Representativeness

Nature policy and land management predominantly focus on the seven groups of species on the RLI. These groups have the greatest resonance with the wider public. Unfortunately, the RLI represents mainly terrestrial and fresh water species. Apart from a few sea mammals, marine species are lacking entirely.

Relevance for nature policy

During the past two decades, policy was aimed at averting the loss of biodiversity. Emissions considered harmful to the environment were reduced on a large scale and in many areas measures were taken to restore nature values (PBL, 2012). The area where nature is protected has grown and environmental conditions and water quality have improved. After many years of loss of biodiversity or - at best - a slowdown of the deterioration process, it seems that the number of threatened species in the Netherlands starts te get smaller. Whether this improvement is the result of measures taken in the past is subject to further investigation. The RLI criterion agrees with the international conventions ratified by the Netherlands, in particular the Bern Convention, the Biodiversity Convention and the EU biodiversity target. These conventions aim to prevent the loss of indigenous species in the Netherlands.
As from 2015, the Ministry of Economic Affairs has incorporated the RLI in its current form in the report to the parliament explaining the national budget.