Lime debris heaps

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Lime scree slopes with Dinaric Columbine . Orjen Mountains, Sub-Adriatic Dinarides
Periglacial frost pattern soils on lime. Frost weathering creates periglacial layers. Pioneering plants such as the white silver arum ( Dryas octopetala ) settle here . In addition, Scabiosa silenifolia , Carex kitaibelliana and Salix retusa
Rough dandelion (subsp. Hyoseroides ) on fine limestone scree

Lime scree slopes are a type of landscape and substrate in areas that are built up from carbonate rocks. Geomorphologically , they are an accumulation of calcareous loose rock, which has arisen in situ from the surrounding rock through frost weathering , or which is accumulated as debris at the foot of the mountain through gravitational processes from higher slope steps from rock fragments. From the geomorphological processes that affect the landscape, limestone scree slopes can either be calm or highly mobile. They are widespread from the hilly low mountain range to the subnival level of the high mountains. In the periglacial (sub) arctic areas, they occur in a circumpolar manner in completely flat areas. Material sorting and frost pattern soil formation occurs here through freezing and thawing processes of the soil. In the Alps, on the other hand, floating soils can form over limestone soils . In alpine high-altitude zones, calm limestone scree slopes always form snow- accentuated habitats that are the location of limestone-snow- soil societies in primary succession . As such, they are designated as legally protected biotopes in the BNatSchG ( Section 30 ) . The Faun-Flora-Habititat Directive in the EU Natura 2000 network lists them in habitat code 6170.

ecology

The limestone scree habitat is characterized by the mostly small proportion of fine sediments. Very different grain size fractions dominate, ranging from blocks (> 25 cm) to coarse rock (2–25 cm) and gravel (0.2–2 cm) made of rubble of all possible grain size classes. Due to the primary porosity and excellent water conductivity of limestone scree slopes, their high-ranking significance in the landscape balance results from the climatic excess of water and the resulting lateral water movements into the soil. In the sub-oceanic Northern Limestone Alps, they are ecotopes of the fresh seepage regimes with episodic drying phases (steep slopes) and flowing transitions to the seepage water regime with partial wetness and waterlogging (moderate slope, shady northern slopes). Supplementary water and groundwater regimes are only possible in the Karboden area, but here, too, there is drying out in midsummer after the last remains of snow have disappeared. The situation is different in the Southern Alps or the subtropical limestone mountains. Here limestone heaps often form very dry ecotopes that enjoy high amounts of heat.

Limestone scree slopes are particularly cold locations in nemoral high mountains such as the Alps, Pyrenees, Dinarides or the Caucasus . The enclosed air volume in the gaps between the gaps ensures good insulation against floor heating. This is also true even though the open areas can warm up considerably from exposure to the sun. However, the heat does not penetrate into the ground. With the rock shield, the short-wave solar radiation is also reflected and the rock layers are well insulated against high water evaporation . Therefore, limestone debris heaps are often the representatives of the limestone snow valley flora, in which creeping willows are character species. Due to this particular location apert snow from relatively late Kalkschutthalden.

Lime scree slopes can be divided into three basic types:

  • active with constant material supply
  • calms without material addition, but flexible
  • stabilized, completely immobile

Habitat for animals and plants

Larval habitats of the Red Apollo are sedum- rich limestone scree slopes

The flora and fauna of the limestone scree differ in the high and low areas. Typical plant species in alpine limestone scree are z. B. Woolly reed grass ( Calamagrostis villosa ), Round-leaved Täschelkraut ( Thlaspi rotundifolium ), Alpine butterbur ( Petasites paradoxus ) or more frequently Creeping gypsum herb ( Gypsophila repens ), dwarf bellflower ( Campanula cochleariifolia ), bladder campion ( Silene vulgaris ) or sign -Bampfer ( Rumex scutatus ). Einseles Columbine settles on dolomite . Various types of dandelion are also common: Leontodon hispidus subsp. pseudocrispus , Leontodon hispidus subsp. hyoseroides in the Alps and Leontodon crispus ssp. crispus in the Southern Alps, Appenines and mountains of Southeast Europe.

The limestone scree slopes of the Balkan Peninsula are rich in endemics. Here in particular in the Dinarides and in the Pindus . In the Dinarides, for example, the conspicuous tufted bells (especially Edraianthus serpyllifolius ) or the endemic large-flowered columbines ( Dinaric columbines and Kitaibel columbines ) can be found in limestone scree slopes.

The espalier shrubs white silver arum ( Dryas octopetala ) and blunt-leaved willow ( Salix retusa ) are special limestone scree pioneers in the Alps, Carpathians and Dinarides . You can secure calmed rubble heaps. The mountain dandelion ( Scorzoneroides montanus ) populates heavily to heavily moved scree slopes (such as in the run-up to glaciers ). The mountain dandelion dumps (Leontodontetum montani) are particularly species-poor locations and are found only very irregularly in the Bavarian Alps. In particular, however, they are widespread on the Zugspitzplatt . In addition to the mountain dandelion heaps as a society of moving debris, those of the agitated calcareous debris heaps of the snow valleys with the species-poor societies of the Täschelkrauthalde (Thlaspietum rotundifolii) and the rock cress snow valley (Arabidetum caeruleae) are settled. The most common plant community on the Zugspitzplatt is the Täschelkrauthalde on all scree slopes below the Plattumrahumg and in places as far as the lower alpine zone. A degree of coverage of 10–15% is characteristic. Physiological adaptations of the plants are resilient roots and shoots. Espalier bushes such as creeping willows use the partial covering of rubble as protection against severe frost. The buds and shoots are better protected in the air spaces of the coarse blocks as well as the growth form pressed against the ground against the deepest, damage-causing frosts.

The uneven subsoil is an important habitat for invertebrates such as insects and spiders and serves as a retreat for many relic species. Among the ground beetles are z. B. Species of the genera Bembidion and Nebria are represented. Some of the rare alpine butterflies with geographical restrictions, such as the red apollo , the glacier butterfly , the yellow-spotted carrot or the alpine moth mother-of-pearl butterfly, are adapted to their larval habitats with the food plants that only occur on limestone scree and scree meadows. In addition, Engadine bears and ice moors are also worth mentioning in the Alps for the relic characteristics of the location.

Alpine brown flies , ptarmigan and wheatear are typical bird species that can be encountered here.

distribution

Limestones like calcite and dolomite are prone to frost weathering. In temperate mountains, which are mainly composed of dolomite and limestone, the accumulation of frost cycles and periglacial weathering are the cause of the formation of limestone scree. In the Bavarian Alps these are u. a. striking at the Zugspitzplatt or in the Berchtesgaden Alps. In the Southern Alps, heaps of rubble emerge in the Dolomites. Mountain streams may transport lime rubble into deeper valleys. As a result, typical representatives of the limestone rubble flora can also occur in overgrown river beds. The white silver arum in the Isar valley descends on the accompanying limestone pebbles to Bad Tölz .

Area and species protection

Lime scree slopes are comparatively small. Their main Alpine distribution is limited to certain altitude zones above the tree line in the Northern and Southern Limestone Alps. Since the altitude distribution and the microclimate result in special living conditions in which the competitive power of lime-loving grass species decreases in favor of espalier bushes, the species of these habitats also have different requirements than the social complexes spread over fine-earth locations in the same altitude zone. Depending on the type of location, the thickness and duration of the snow cover in the interplay with small relief and wind effects are also more important than the general macroclimate. The image of the isochions is very clearly reflected in the vegetation mosaic of the limestone scree . It is also irrelevant whether the temporal distribution of the snow cover is subject to strong fluctuations every year and is therefore dependent on the weather; Spatially, the snowpack is characterized by an always constant annual distribution of the isochions. Limescale heaps are very different from other locations due to lower evaporation and lower wind effects as well as cryoturbation and higher soil moisture. Above the subsoil with different levels of consolidation or mobility, they offer a high variety of small-scale locations. The main threat to these locations comes from climate change, as the species adapted to the habitat are more sensitive to temperature than other habitats.

Individual evidence

  1. ↑ Thorsten English: Multivariate analyzes of the syn systematics and site ecology of the snow floor vegetation (Arabidetatlia caeruleae) in the Northern Limestone Alps. In: Stapfia. 59, Linz 1999, pp. 1-211 ( PDF on ZOBODAT ).
  2. ↑ Law on Nature Conservation and Landscape Management (Federal Nature Conservation Act - BNatSchG). In: gesetze-im-internet.de. Retrieved May 11, 2020 .
  3. ↑ BFN - Natura 2000 NATURA 2000 Code: 6170 .
  4. ↑ Stefan Bräker: Landscape development and landscape processes in an alpine high valley of the Northern Limestone Alps (Oberjoch / Allgäu Alps). Z. Geomorphology Sppl. Vol. 147, 2006, pp. 55-76.
  5. ↑ Aquilegia einseleana .
  6. ↑ Leontodon hispidus subsp. pseudocrispus .
  7. ↑ Oliver Korch, Arne Friedmann: Phytodiversity and dynamics of the flora of the vegetation of the Zugspitzplatt. In: Yearbook of the Association for the Protection of the Mountains. 76/77, 2012, pp. 217-234.
  8. ↑ Christian Körner: Alpine Plant Life. 2nd edition, Springer, 2003, ISBN 3-540-00347-9 , p. 108.
  9. ↑ Wolfgang Wagner 2005-2019 Roger Apollo
  10. ↑ European butterflies and their ecology - Engadine bear (Arctia flavia) .
  11. ↑ European butterflies and their ecology - Ice Mohrenfalter (Erebia pluto) .
  12. ↑ Christian Körner: Alpine Plant Life. Springer, 2nd edition, Berlin 2002.
  13. ↑ Thorsten English: 1999, p. 57.
  14. ↑ Magalì Matteodo, Klaus Ammann, Eric Pascal Verrecchia, Pascal Vittoz: Snowbeds are more affected than other subalpine – alpine plant communities by climate change in the Swiss Alps. Ecology and Evolution, 6/19, 2016 ( [1] ).

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