11 



A. Ghamaephyte and Nanophanerophyte 



formations. 



The Chamaephytes of the heather moor (especially Calluna, Em- 

 petrum nigrum, Erica tetralix, Arctostaphylos uva ursi) are dominant, 

 wherever there is not too much moisture, chiefly on the mineral soil, but 

 also on the sufficiently dry peaty ground; on the latter we often find 

 in addition theVnanophanerophyte Myrica gale. According to the dom- 

 inant plant we may divide these formations into: 



1. Callunetum. 



2. Ericetum. 



3. Myricetum. 



4. Mixed formations (especially Calluna-Empetrum heath and Cal- 

 luna-Erica heath). 



The Callunetum. According to the dampness, richness and exposure 

 of the ground Calluna assumes a very variable appearance, and the 

 age of the crop makes a distinct mark on the physiognomy. Young 

 communities form fresh, brownish green carpets, but soon the growth 

 becomes open and tufty, Cladonia rangiferina is added, and thus, 

 by contrast also with the pale colour of the old heather stems, the brown 

 colour of the older Callunetum becomes spotted with gray. Often 

 we meet with a very open Calluna heath on high and dry ground with 

 sparsely covered sandy spots between the tufts of heather; the first immi- 

 grants on sand of this kind (formed by heath fires, gusts of wind or 

 the like) are Polytrichum pilosum and lichens (Lecidea decolorans, 

 Cetraria islandica); later we often find a community of grasses and 

 sedges (Aira flexuosa, Festuca ovina, Weingartneria, Carex are- 

 naria and others) with their accompanying plants and gradually the 

 Chamaephytes arrive. At many places, especially on the slopes of the 

 ridges, the Callunetum assumes a yellowish-green tone from abundance 

 of mixed and even predominating Empetrum; at places Arctostaphylos 

 forms dense mats, or Vaccinium vitis idaea becomes very prominent. 

 As commoner, accompanying plants in the dry Callunetum, in ad- 

 dition ta the above species, we may note: Antennaria dioeca, Arnica 

 montana, Carex panicea, C. pilulifera, Genista anglica, Hieracium pilo- 

 sella, H. umbellatum, Juncus squarrosus, Nardus stricta, Potentilla erecta, 

 Salix repens, Solidago virga aurea; Stereodon ericetorum often forms 

 a dense mat under the heather tufts. On stony, wind-swept ground 

 the heather shows only a paltry growth, whereas on peaty soil it forms 

 very strong tufts up to a metre high; on such spots it is mixed 

 with Erica tetralix, and other accompanying plants are also added to 

 some extent: Andromeda polifolia, Eriophorum polystachyum, E. vagi- 

 natum, Juncus species, Molinia coerulea, Myrica gale, Oxycoccus pa- 

 luster, Scirpus caespitosus; Leucobryum and other mosses, especially 

 tufts of Sphagnum. 



