KENFIG IJURROWS: AN ECOLOGICAL STUDY 21 3 



of bright green colour everywhere, and are particularly obvious 

 during the early spring. 



The following detailed description of the associations is not 

 intended to be exhaustive. Many problems arising out of the 

 distribution of the dependent species in this formation have yet to 

 be solved, and the listing of associated types is but a step on the 

 way to their complete elucidation. No sharp line can be drawn 

 between two associations, and it is often difficult to determine 

 whether a certain species belongs to one association or to another. 



In the Kenfig sand-dune area the Salix repetis association is of a 

 transitional type. In its more open stations on the mobile dunes 

 the majority of its subordinate species are those of the Marram 

 grass association. Towards its inner limit, fixation of the sand is 

 complete, and the included species are those of the fixed dunes 



Before enumerating the species which are found in the chief 

 associations, it is necessary to call attention to the plants which 

 occupy the foreshore, above high-water mark. These plants are 

 usually included in the sand-dune formation, although, as a rule, 

 they are more of a halophilous nature. This association of strand 

 plants is not well developed on this part of the coast ; only a few 

 species occurring here and there. The following are the commoner 

 species : Cakile maritima, Scop. : Arenaria peploides, Linn. ; Salsola 

 Kali, Linn. 



Marram Grass Association. 



In the "flats" and sheltered hollows among the "shifting" dunes 

 the following species occur : — 



DOMINANT SPECIES. 



Amniophila arenaria, Link. 



ABUND.^NT SPECIES. 



JLrodiian cicutarinni, L'Herit. ILiiphorbia Paralias, Linn. 



Anaphalis margaritacea, B. & Euphorbia portlandica, Linn. 



H. fil. Iris foetidissima, Linn. 



Se?tecio /acobcea, Linn. Carex arenaria, Linn. 

 Cnicus arvensis, Hoffm. 



FREQUENT OR OCCASIONAL SPECIES. 



Erigeron acre, Linn. Cynoglossufu officinale, Linn. 



Taraxacum erythrospermum, Verbascum Thapsus, Linn. 

 Andrz. Verbena officinalis, Linn. 



The variety glandulosujn, Bosch., of Erodiiim cicutarium has been 

 recorded from this district. Anaphalis margaritacea is well established 

 on the dunes, and apparently succeeds best where competition is 

 reduced to a minimum. Cnicus arvensis colonises the sandv ho'lows 



