SANDPIT COVERT MARSHES, BLYTHBURGH, III By P . J . O . TRIST
IN 1953, these marshes were re-enclosed after having lain lost to the tidal waters of the River Blyth for thirty years. Previous accounts of the re-appearance of natural flora are recorded in Vol. IX, Pts. I and III. With the exception of 1957, annual observations have been made and the accompanying list shows the gradual reappearance of the various species. In the first two years after re-enclosure, the only plants recorded were a few halophytes which are very tolerant to high saline conditions. At the same time, the sah (NaCl) in the soil has over the past five years fallen considerably and it will be seen that all of the original immigrants continue to persist, with the exception of the Cord Grass (Spartina tozvnsendii) and two species of Salicornia*, of which a few plants were found in 1954 and 1955. The more common species, S. stricta, has continued to persist in isolated depressions. Date of Sampling. NaCl % in 6" soil Sept. 1953 1.57 „ 1954 1.29 „ 1955 1.80f „ 1956 0.57 Apr. 1957 0.40 „ 1958 0.12 In 1954 Spartina established itself in several small colonies, but by September, 1956, the normal conditions for its growth had been considerably altered and the plant disappeared. Both the Carex otrubae and Ranunculus sceleratus were isolated colonies, introductions on or near ditch banks. By 1955, in spite of a rise in the salt percentage in the soil, due to a breach in the wall causing new flooding in December, 1954, the salt marsh ränge of flora common to this area started to establish itself, but over large areas Salicornia stricta and Suaeda maritima remained the dominant flora. Juncus, Scirpus, Eleocharis and Typha were all confined to low places, old tide Channels or near the sides of ditches : in fact, in close proximity to places where fresh water stood or moved. The Atriplex spp. neither formed a dominant ground cover nor grew into such large plants as were seen on other marshes after the 1953 floods. This can be explained : first, the number of plants on the old river walls was not great and the possible release of viable seeds would be limited. Secondly, by comparison with conditions elsewhere after the 1953 flood, the Sandpit Covert *Sclicornia prostrata and ramosissima (identified by Kew). t F u r t h e r salt water flooding in December, 1954.