High moor biotopes are highly specialized habitats - not entirely land biotopes and not entirely water biotopes either. In this gray area in between, living conditions are very inhospitable for some residents. They have to contend with low oxygen levels and high acidity. The plants of the moors fed by rainwater are highly specialized, they don’t grow anywhere else. If the special characteristics of the high moors are lost to drainage, the species native to the high moors are lost as their habitat disappears - forever.
Peat moss (sphagnum ssp.) are adapted to the wet, acidic, and low-nutrient conditions in the high moors. They don’t have roots and will grow incessantly at heights - while the moss at the top continues to grow, the lower layers of moss die. The form the so-called peat moss bed. The image shows a scheme of different species of peat mosses and their anatomy.
The peat mosses are the most important peat architects of the high moor. They are capable of retaining twenty to thirty times their dry weight in water - so they suck it up like a sponge. This ability stems from peculiarities of their anatomy - not only do the leaves of the peat moss have chlorophyll sells for photosynthesis, but they also have hyaline cells for water retention. Another important characteristic of peat mosses is the exchange of ions. Alkali or alkaline earth ions, such as calcium and magnesium, are embedded in the cell walls, while hydrogen ions are released into the surrounding water. This increases the acidity of the groundwater. The living conditions are thus worsened for higher plants and sphagnum species remain competitive.
Peat mosses a visually differentiated mainly by their color. Yellowish green species, such as sphagnum cuspidatum and sphagnum tenellum, reside mainly in water-filled mud bottoms, growing underwater or near the water’s surface. Red or redish brown species, such as sphagnum capillifolium and sphagnum rubellum, live mainly on the somewhat dryer hummock.
The lack of nutrients in the moors is a limiting factor that prevents the growth of higher plants - the so-called insectivorous plants obtain the nitrogen they need to grow from the protein in their prey. The round-leaved sundew (Drosera rotundifolia) is an example of a higher plant that grows on the peat moss hummocks of open moor areas. The leaves are covered in rounded digestive glands that react to stimulation. Drops of sticky digestive enzymes stick to the gland hairs, capturing small animals (insects, spiders) and digesting them (COLDITZ, 1994).
Another group of species native to the high moors is the dwarf shrubs. These plants take advantage of other opportunities to overcome the lack of nutrients in the ground: Fungus grows on the roots of the dwarf shrubs in a symbiotic relationship (mycorrhiza). The hyphae of the fungi enhance nutrient absorption in plants (COLDITZ, 1994).
Some of them are plants associated particularly with the moor environment such as bog bilberries (Vaccinium uliginosum), bog rosemary (Andromeda polifolia), crowberries (Empetrum nigrum), and cranberries (Vaccinium oxycoccus) - which grow exclusively on peat. Other species such as common heather (Calluna vulgaris), European blueberries (Vaccinium myrtillus), and cranberries (Vaccinium vitis-idea), grow on the mineral ground of the forest. The ideal growth conditions for all dwarf shrubs are found, however, on the acidic ground substrates offered by peat.
Common heather (Calluna vulgaris) grows in dry areas, offering one last burst of color in the moors in the fall.
Cranberries (Vaccinium oxycoccus) are an evergreen plant that forms small, creeping shoots upon which small, leathery leaves grow. In the fall, the shoots bear relatively large, red, firm berries located directly on the ground.
Bog rosemary (Andromeda polifolia) is a relic of the Ice Age and has already disappeared in many moors with well-preserved sections, such as the Georgenfelder High Moor in the Eastern Ore Mountains. This species, which has been classified as critically endangered (Red List - 2), still persists in the Mothhäuser Haide nature preserve luckily.
Bog bilberries (Vaccinium uliginosum) grow exclusively on peat. They bear blue berries similar to European blueberries, but that are white inside. It has been said that eating a large quantity of these berries would heighten a person's senses. There is no proof of this.
Cranberries (Vaccinium vitis-idea) are evergreen dwarf shrubs the form deep red, somewhat bitter tasting berries in the fall. The acidic earth offers ideal growth conditions.
Crowberries (Empetrum nigrum) have only survived in well-preserved moors such as here in the Kleiner Kranichsee nature preserve. It is listed as endangered on the Saxon Red List (3). The blue berries in the photo aren’t crowberries, but rather a very elaborately grown European blueberry (Vaccinium myrtillus).
Sedges are one of the main higher plants that grow in the moors. Species typical of the moor include hair’s-tail cottongrass (Eriophorum vaginatum) and common cottongrass (Eriophorum angustifolium). Both species are easily recognizable by their white flower clusters that appear in about June. At that time, they grace the entire moor area with their cotton-like flowers.
While hair’s-tail cottongrass only bears one flower per stem, common cottongrass will bear multiple flowers on a single stem.
Dryer parts of the moor, the sloped boarders or even drained moors for example, are home to trees native to the moor. This includes the bog pine (Pinus mugo) and in its mountain pine form (Pinus mugo ssp. rotundata), the upright type of the mountain pine, the spirke (Pinus mugo ssp. Uncinata), and also the moor birch (Betula pubecsens).
When conditions are too dry, pines also lose their competitive edge and are driven out by spruce, which will result in the beginnings of a spruce moor forest in the bordering areas.