Rubble vegetation

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Rubble vegetation is the population of plants on rubble heaps and the like. Ä. These represent a very extreme environment for plants in which adaptations to the rough and inhospitable conditions are inevitable. For plant species in this habitat, adjustments to the following conditions are necessary:

1. The upper layers of rubble dry out very quickly; Direct sunlight and the drying wind are the main reasons for this. Rainwater also seeps away very quickly in coarse surface debris. Furthermore, there is little soil here that could store water. So moisture is in short supply here. However, these upper stone layers keep the drying wind away from the lower layers, so that these are protected from drying out.

2. Fine soil is only available in small crumbs where it is deposited by regular water flow. It is therefore a matter of luck that seeds accidentally germinate precisely in these locations.

3. The rock above the scree is increasingly eroding. Rockfall results. This means that substrate movements increase on steep slopes. The plants are spilled, torn, crushed, uprooted. So there is a balance between plant colonization and destruction through mechanical stress

Kalkschuttflur, Schynige Platte, Canton Bern (CH)

Adjustments

In order to get to the moist fine soil, debris plants usually develop extensive roots. Strong tap roots are used to anchor in loose rock, while fine roots are used to absorb water and nutrients.

Schroeter (1932) subdivides the growth forms as follows:

The species germinates relatively quickly, as the young plant must quickly reach the surface or light from the crumbs of fine soil below. For example, a 10-day-old seedling of the round-leaved pocketwort was already measured to be 20 cm long. Most debris plants are also characteristic of runners and creeping shoots. On the one hand, this strengthens the subsoil, and on the other hand, it increases the ability to regenerate after a spillage.

Lime rubble corridor

The plants also find the following factors on a heavily calcareous subsoil: The pH of the subsoil is in the range of 6-8. The chemical composition of the lime is responsible for this. HCO3- dissolves from the lime . This catches the protons, producing water and carbon dioxide. This prevents acidification of the subsoil. The high content of calcium ions and HCO3-. however, it can damage the plant. This must therefore take special measures. Nutritional ions such as iron, phosphorus and manganese are also difficult to absorb. Nitrogen is v. a. present in the form of nitrate. The plant must have a nitrate reductase to absorb them.

Taschelkraut-Kalkschuttflur ( Thlaspietum rotundifolii ): low degree of coverage (5–10%), relatively few species. Typical types are:

Silicate rubble corridor

In return, silicate communities have an acidic subsoil (pH 3–6). Aluminum is readily soluble, but large quantities of it are toxic to plants. Nitrogen lies v. a. as ammonium. Lime-loving plants could not absorb this form.

Acid silicate rubble corridor ( Sieversio-Oxyrietum-digynae ): Physiognomy similar to the flask herb calcareous rubble corridor, but more species-rich. Typical types are:

See also

Individual evidence

  1. ↑ Schroeter, Carl: The plant life of the Alps - A description of the high mountain flora; 2nd edition with Marie and Heinrich Brockmann-Jerosch, August Günthart and Gottfried Huber-Pestalozzi. Zurich: Albert Raustein, 1926