Red List habitat classification > RLH - Sparsely vegetated habitats > RLH5.1b Polar desert

Polar desert

Quick facts

Red List habitat type code RLH5.1b
Threat status
Europe Near Threatened
EU -
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)

Summary

Polar deserts comprise stone- and gravel-dominated areas north of or at elevations above the Arctic tundra zone where the vegetation cover is fragmentary owing to low temperatures and where woody plants and sedges are lacking. This is a circumpolar arctic habitat type that has in common with the ‘true deserts’ that precipitation is extreme low (< 200 mm yearly) and the vegetation growth period is very short. Around the Isfjord on Svalbard, an area very positively affected by the north atlantic current, the growing season for example is about 40-50 days. The habitat is characterized by extreme low summer temperatures (< 2 °C mean summer temperature, considered as the most important abiotic factor), shallow soils over permafrost (which is instable due to cryoturbation, causing honeycomb soil patterns), and little relief (resulting in low snow cover). Polar deserts consist of fine to medium coarse substrates resulting from frost weathering processes with particle sizes ranging from silt to gravel and stones. The sediment in most sites is calcium-rich, but acidic bedrock may occur as well. Polar deserts are restricted to continental areas influenced by cold sea currents from the Arctic Ocean.

The habitat has in general a very low vegetation cover (1-10%) or is in some areas completely free of plants. Species characteristic for Polar deserts are Cerastium nigrescens subsp. arcticum, C. regelii, Draba pauciflora, Luzula confusa, Papaver dahlianum, Phippsia algida, Saxifraga hyperborea and S. oppositifolia, which usually grow scattered. In between mosses and crustose lichens may be found in rock crevices; these are mainly wide-spread species. Locally, plant cover in Polar deserts may be increased owing to favourable abiotic conditions. For instance, at sites better protected from wind and frost, species like Stereocaulon rivulorum and Phippsia algida may be abundant. Increased nutrient input in areas colonized for long time by reindeer, like on the plateaus of Edgeøya, may enable an increased growth of byrophyte mats dominated by Tomentypnum nitens. Such areas, although in the climatic region of the polar desert, are considered Moss tundra habitat (F1.2). Some of the polar desert species (Luzula confusa, Papaver dahlianum, Phippsia algida) also grow in slightly warmer climates, in habitats with little competition with other species.

Polar deserts are typically found in the flat or slightly undulating lowlands and on mountain plateaus of eastern and northern Svalbard, and on glacier free parts of the Russian islands in the Barents Sea (Franz-Jozef-Land, Victoria islands and Nowaja Semlja). The mountains of these regions may have a similar plant species composition on scree habitats (type H2.1, H2.1). Moreover, Polar deserts occur all over Svalbard at elevations above 200 to 500 m a.s.l.  A difference with Moss and lichen tundra (F1.2) is the general lack of typical tundra species (e.g. Carex spp.) including woody species (e.g. Salix spp., Dryas octopetala and Silene acaulis).

Indicators of good quality

This is natural vegetation occurring in remote areas which are under limited human influence. It is generally rather stable, but may be threatened by global warming.

The following characteristics can be considered as indicators of good quality:

  • Long-term stability of low vegetation cover
  • Abundance of species sensitive to changes in soil moisture and temperature (like Draba adamsii, Cerastium regelii, Saxifraga hyperborea)
  • Absence of long living and slow colonizing species indicating global warming, like Silene acaulis, Dryas octopetala, Salix polaris and Festuca rubra ssp. richardsonii

Characteristic species
For full habitat description, please download the habitat factsheet.

Threat status

Synthesis of Red List assessment

No data on past trends in quantity and quality are available. However, for the near future it is expected that the habitat will decrease both in area and quality as a result of climate change. The relatively small EOO combined with a serious threat results in the category Near Threatened (NT) for criterion B1. The expected changes in quality results in the same category for criterion C/D2. The category Near Threatened is the same result as was given by experts in the Norwegian Red List of Ecosystems.
EU
Red List Category Red List Criteria
- -
Europe
Red List Category Red List Criteria
Near Threatened B1, C/D2

Confidence in the assessment

low
Red List of habitat categories and criteria descriptions

Pressures and threats

  • Mining, extraction of materials and energy production
    • Open cast mining
  • Pollution
    • Acid rain
    • Nitrogen-input
  • Climate change
    • Changes in abiotic conditions
    • Changes in biotic conditions

Habitat restoration potential

Only naturally. Recovery processes occur very slowly in the cold arctic climate.

Trends in extent

Average current trend in quantity

No occurrence Unknown
EU28 EU28+

Trends in quality

Average current trend in quality

No occurrence Unknown
EU28 EU28+

Conservation and management needs

The protected areas now cover 65 % of the Svalbard land area. All known habitats, including polar deserts, are well represented in these areas, where regulations provide robust protection against any material impact on the natural landscape. Provisions for hunting in protected areas vary. Snowmobile driving is permitted in some national parks near settlements. As most of Svalbard is now largely free of human influence, the archipelago is of great value as a reference area for research on the effects of climate change, transboundary pollution and other large-scale environmental impacts.

List of conservation and management needs

  • No measures
    • No measures needed for the conservation of the habitat/species
  • Measures related to spatial planning
    • Establish protected areas/sites

Distribution

For each habitat a distribution map was produced from a wide variety of sources indicating known and potential occurrences of the habitat in 10x10 km grids within Europe. Occurrences in grid cells were given in two classes: actual distribution from relatively reliable sources (surveys, expert knowledge), and potential distribution based on models or less reliable indicators. Please download the fact sheet to see the map.

Geographic occurrence and trends

EU28 Present or presence uncertain Current area of habitat (Km2) Recent trend in quantity (last 50 years) Recent trend in quality (last 50 years)
EU28 + Present or presence uncertain Current area of habitat (Km2) Recent trend in quantity (last 50 years) Recent trend in quality (last 50 years)
Svalbard Present 5000 (2850-7500) Unknown Unknown

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 -- -- -- No occurrence in EU 28
EU28+ 419 5000 (2850-7500) Johansen et al. 2009, Lindgaard & Henriksen 2011
AOO = the area occupied by a habitat measured in number of 10x10 km grid cells.
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).

Characteristic species

Not available

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

Not available
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