260 SUCCESSION IN EURASIA. 



Fritsch and Parker (1913 : 215) have described the recolonization of heath 

 burns: 



Within a few months after the fire, Ulex minor and U. europaeus were found 

 sprouting afresh, while numerous Ulex seedlings were growing on the ground; 

 a considerable area bore a growth of Pyronema confliiens, but apart from this 

 and the Ulex there was no other vegetation. In April the fungus had dis- 

 appeared, but otherwise the vegetation of the burnt area showed little change; 

 munerous Ulex seedlings were present, though their nimiber had diminished 

 since January and from other observations it seems probable that only very 

 few of them prosper; at some points Molinia was reappearing, the growth 

 again arising from the old plants; here and there isolated Pteris fronds were 

 coming up, but no other forms yet showed any indication of growth. By July 

 a vigorous growth of the sprouting Ulex had taken place, but the U. minor 

 seedUngs were doing badly, in marked contrast to the behavior of U. europaeus 

 seedhngs on the part of the burnt area situated in valley A, where many had 

 reached a height of 15 to 20 cm., their growth doubtless being favored by the 

 protection of the tall Pteris; numerous Vacdnium shoots were now arising 

 from the old plants, and occasional sprouting Calluna and Erica plants were 

 observed, while seedlings of the two last-named, and especially of Erica, were 

 rather munerous at some points; most of the old Calluna and Erica plants, 

 however, still showed no signs of life. 



These observations tend to indicate that the typical heath representatives 

 are mainly stationary and reappear again in exactly the same positions as they 

 occupied before a fire. A study of the small zone burnt before the survey was 

 begun leads to the same conclusions. The authors distinguish the following 

 four successive stages in the recolonization of burnt grotmd on the Hindhead 

 heath: (1) sprouting of the Ulex; (2) appearance of new growth from the base 

 of other members of the heath flora and development of a niunber of seedlings 

 (Ulex dominant); (3) Calluna, Erica cinerea, Ulex minor, and to some extent 

 Pteris and Vacdnium competing for dominance (C. U. E. facies) ; (4) Calluna 

 (tall) and Ulex minor dominant, all other forms subsidiary (C. U. facies). 



Moss (1913) has considered in thoroughgoing detail the formations of the 

 Peak District of England. The successional relations of the three most 

 important formations, calcarion, oxodion, and silicion, are indicated in the 

 diagrams on page 261 (fig. 21). 



Oliver (1912 : 73; 1913 : 4) has made a thorough study of the shingle-beach 

 as a plant habitat, and has described the communities of the following areas: 



(1) Mobile shingle, (2) stabilized shingle, (3) narrow-mouthed salt-marshes 

 (4) broad-mouthed bays and mud-flats, (5) shingle low. The characteristic 

 halophyte of mobile shingle is Suaeda fruticosa, often with Artemisia; the 

 chief non-halophytes are Silene maritima, Arenaria peploides, Rumex trigranu- 

 latus, Glaucium luteum, and Sedum acre. The stabilized shingle is marked 

 by Suaeda on the slopes, above which lies a zone of Statice binervosa and 

 Frankenia levis, while the crest is occupied by a mixed community. 



Oliver and Salisbury (1913 : 249) have summarized the relation of Suaeda 

 fruticosa to shingle-beach as follows: 



"Provided the conditions permit the establishment of Suaeda on the lee 

 edge of the beach it will, as the beach slowly travels over it, respond by con- 

 tinually growing to the surface. In this way it has come about that Suaeda 



