Lampenflora

Lamp-Flora - Lamp Flora


Lampenflora is the term used to describe the totality of all autotrophic plants that are found in natural or artificial cavities in the area of permanently installed lighting fixtures. The German term "Lampenflora" has also become common in English and is used internationally.

Lampenflora is a problem in show caves and all other underground attractions. It is cool in caves, but there is no frost and also always enough humidity. And with the installation of electric light, the final prerequisite for plant growth is fulfilled. The germs, seeds or spores either come along in the dripping water, come from the air or are carried in by visitors on their clothing. Typical is the growth of algae, then mosses and finally even ferns. In rare cases, even flowering plants can be found. The dominant species are different from those on the surface due to the special conditions in the cave.

Lampenflora develops around a light source, surrounding it in a circle. It usually ends up about 50 cm from the lamp, but this depends greatly on the type of light source. With the earlier light bulbs, however, the heat caused the moisture in the immediate vicinity of the lamp to dry out and the plants there dried out, so that the circle became a ring. LED lamps generally do not produce this effect.

Lampenflora are usually taken very seriously by operators because they alter the caves. Visitors frequently perceive them as unsightly, as pollution. Green rings, but especially plants on dripstones, have therefore been combated for a long time. Of course, lampenflora is even worse in caves with cave paintings. There, the growth would destroy the paintings.

Over the decades, various methods have been tried to combat lampenflora. If possible, it helps to place lamps only in dry places, but these are rare and often not optimal for illumination. It has also been tried to treat the plants with weedkiller, but this is extremely harmful to the cave fauna and is now frowned upon. A much more harmless variant is the use of brine, which is water with a high salt content. This is also not good for the cave fauna, but much more harmless. The main problem with this method is that it has to be used several times a year and is therefore very labour-intensive and therefore expensive. Similarly, having the guides turn the lights on and off for only a few minutes during the tour was not sufficient. It seems that as little as 15 minutes of light a day can be enough. The hope that the light from LED lamps would not be sufficient for the plants was unfortunately not fulfilled, or only partially. Special LED lamps, which largely lack the wavelengths suitable for photosynthesis, have at least greatly reduced the lampenflora. In particularly sensitive caves, electric lighting is therefore dispensed with and visitors are given torches.

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