Lower Abbey Farm Marsh

LOWER ABBEY FARM MARSH On 2nd July, 1955, the Botanical Section of the Suffolk Naturalists' Society, led by Mr. P. J. O. Trist, visited the Minsmere Levels North of Lower Abbey Farm, and both North ancl South of the New C u t ; and were able to see something of the coercion of Nature by the agriculturalist, diverting natural forces, to produce an uniform food producing flora ; and of Nature's reluctance to be so coerced.

Mr. Trist explained that before 1939 the sward of these levels probably consisted of Agrostis spp., Cynosurus cristatus (Crested Dog's-tail Grass Loliurn perenne Perennial Rye-grass) Festuca spp.

(Fescues) Trifolium repens (Wild White Clover) Juncus spp.

(Rushes) and others.

The War necessitated the flooding of this area with sea and fresh water, and it remained under water until 1945.

In 1947, the western part was dominated by Agrostis, and there there was much Juncus commmunis (Common Rush) and patches of Scirpus sylvaticus (Wood Club Rush). In the centre there was no clover or grass and Phragmites communis (Reed) and Scirpus sylvaticus were dominant. There is a healthy hill of sand in this area with Agrostis and Ulex (Gorse) which was not flooded.

Grasses are seeding luxuriantly in the absence of the rabbit.

On the lowest levels Aster tripolium (Sea Aster) was plentiful.

In 1949, four years after the flood of salt water had been released, most of the Marsh was dominated by Phragmites communis, also present in considerable quantities were Scirpus sylvaticus and Scirpus maritimus. There was some Aster tripolium, but salt content in soil samples had fallen considerably, so much so that ploughing and seeding with rye grass and wild white clover, and some alsike clover was undertaken.

Inadequate sea-sluices were the primary cause of fresh water flooding in the two succeeding winters, but cultivations and sowings were continued during the intervening summers.

The first effect of the flooding was to wash out the sodium chloride from the top-soil and in the spring, large areas were covered in Ranunculus aquatilis (Water Buttercup) and Alopecurus geniculatus (Marsh Foxtail).

In the summer of 1951, the Marsh was re-seeded, but evaporation brought salt to the surface, and a salt-tolerant flora, including Aster tripolium, Spergularia salina, Scirpus maritimus and Atriplex hastata developed.

At the time of our visit we found Phragmites communis dominant over large areas that had formerly been rye grass and clover.

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Other areas were plentifully spattered with Phragmites, and obviously in process of reverting to reed bed. Most of the area being colonised was at this season relatively dry. It was also noted that the leaf blades were glaucous and leathery, in contrast with the greener and thinner leaves of plants found further inland.

This was thought to be attributed to the salt content of the soil.

A height of six to twelve inches above the general level was enough to ensure that the sown rye-grass and wild white clover held its own, on its tiny watershed ; and a slight depression had its intensified salt tolerant flora, Aster tripolium in particular.

Other associations noted included Alopecurus geniculatus and Glaux maritima (Sea Milkwort) not found off saline soil; Spergularia salina, another salt-tolerant plant and Glaux maritima, a typical area of which had about 60 % S. salina and 20 % G. maritima ; and the Phragmites areas.

In these areas a few minute plants of Ranunculus aquatilis, Âą 1 cm. high with one flower of about 4 mm. diameter, were found, the last stragglers of the fresh-water flooding. Some deformed Ranunculus plants were found, one of which seemed to be a hybrid between R. bulbosus and R. sceleratus.

Other plants noted were Myriophyllum spicatum (Spiked Water Milfoil) whose brick-red spikes dotted one of the dykes, the curious local Hydrocharis morsus-rance (Frogbit) a free-floating aquatic, Lemna polyrrhiza (Great Duckweed) with relatively large redflushed fronds and Lemna trisulca, the Ivy-leaved Duckweed.

A fine colony of Althcea officinalis (Marsh Mallow) was noted and a mile-long river wall of Agropyron pungens (Sea-couchgrass).

On some bare patches within the Marsh, where dredged material from the river bed had been placed in the black soil, Rumex acetosella (Sheep's Sorrel) grew. The soil looked sour and acid but when tested was found to have a pH value of 6.

As we returned across the Marsh from East to West, crossing narrow river-spanning planks, and noting a few plants of Oenanthe fistulosa, it was interesting to note also, the change from a salt tolerant flora, to a freshwater flora of Lychnis flos-cuculi (Ragged Robin), Iris pseudacorus (Flag Iris), Phalaris arundinacea eight feet high, and typical meadowland plants, with a few plants of Triglochin palustris (Marsh Arrow Grass).

The party of about twenty members enjoyed its tea by Tuppenny Bridge ofbygone importance, spanning a river skimmed by swallows, and expressed its thanks to Mr. Trist for an instructive and pleasurable afternoon.

N.

S.

P.

MITCHELL.